diff --git a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664.cpp b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664.cpp
index ed9dd32878..ed6fe813f5 100644
--- a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664.cpp
+++ b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664.cpp
@@ -42,27 +42,9 @@ PANEL_ELECTRICAL_SPACING_IEC60664::PANEL_ELECTRICAL_SPACING_IEC60664(
         long style, const wxString& name ) :
         PANEL_ELECTRICAL_SPACING_IEC60664_BASE( parent, id, pos, size, style, name )
 {
-    m_OVCchoice->Append( _( "OVC I" ) );
-    m_OVCchoice->Append( _( "OVC II" ) );
-    m_OVCchoice->Append( _( "OVC III" ) );
-    m_OVCchoice->Append( _( "OVC IV" ) );
     m_OVCchoice->SetSelection( 0 );
-
-    m_insulationType->Append( _( "Functional" ) );
-    m_insulationType->Append( _( "Basic" ) );
-    m_insulationType->Append( _( "Reinforced" ) );
     m_insulationType->SetSelection( 0 );
-
-    m_pollutionDegree->Append( _( "PD1" ) );
-    m_pollutionDegree->Append( _( "PD2" ) );
-    m_pollutionDegree->Append( _( "PD3" ) );
-    m_pollutionDegree->Append( _( "PD4" ) );
     m_pollutionDegree->SetSelection( 0 );
-
-    m_materialGroup->Append( _( "I" ) );
-    m_materialGroup->Append( _( "II" ) );
-    m_materialGroup->Append( _( "IIIa" ) );
-    m_materialGroup->Append( _( "IIIb" ) );
     m_materialGroup->SetSelection( 0 );
 
     wxString msg;
@@ -80,7 +62,7 @@ PANEL_ELECTRICAL_SPACING_IEC60664::~PANEL_ELECTRICAL_SPACING_IEC60664()
 
 void PANEL_ELECTRICAL_SPACING_IEC60664::ThemeChanged()
 {
-    m_creepageclearanceBitmap->SetBitmap( KiBitmap( BITMAPS::viacalc ) );
+    m_creepageclearanceBitmap->SetBitmap( KiBitmap( BITMAPS::creepage_clearance ) );
 }
 
 
@@ -89,7 +71,7 @@ void PANEL_ELECTRICAL_SPACING_IEC60664::SaveSettings( PCB_CALCULATOR_SETTINGS* a
     if( !aCfg )
         return;
 
-    aCfg->m_Electrical.iec60664_ratedVoltage = DoubleFromString( m_ratedVoltage1->GetValue() );
+    aCfg->m_Electrical.iec60664_ratedVoltage = DoubleFromString( m_ratedVoltage->GetValue() );
     aCfg->m_Electrical.iec60664_RMSvoltage = DoubleFromString( m_RMSVoltage->GetValue() );
     aCfg->m_Electrical.iec60664_transientOV = DoubleFromString( m_transientOvervoltage->GetValue() );
     aCfg->m_Electrical.iec60664_peakOV = DoubleFromString( m_peakVoltage->GetValue() );
@@ -109,7 +91,7 @@ void PANEL_ELECTRICAL_SPACING_IEC60664::LoadSettings( PCB_CALCULATOR_SETTINGS* a
     if( !aCfg )
         return;
 
-    m_ratedVoltage1->SetValue( wxString( "" ) << aCfg->m_Electrical.iec60664_ratedVoltage );
+    m_ratedVoltage->SetValue( wxString( "" ) << aCfg->m_Electrical.iec60664_ratedVoltage );
     m_RMSVoltage->SetValue( wxString( "" ) << aCfg->m_Electrical.iec60664_RMSvoltage );
     m_transientOvervoltage->SetValue( wxString( "" ) << aCfg->m_Electrical.iec60664_transientOV );
     m_peakVoltage->SetValue( wxString( "" ) << aCfg->m_Electrical.iec60664_peakOV );
@@ -129,7 +111,7 @@ void PANEL_ELECTRICAL_SPACING_IEC60664::LoadSettings( PCB_CALCULATOR_SETTINGS* a
 
 void PANEL_ELECTRICAL_SPACING_IEC60664::CalculateTransientImpulse()
 {
-    wxString              string = m_ratedVoltage1->GetValue();
+    wxString              string = m_ratedVoltage->GetValue();
     double                value = 0;
     IEC60664::OV_CATEGORY ovc;
 
diff --git a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.cpp b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.cpp
index 3a7d3a6a88..9afcd8f332 100644
--- a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.cpp
+++ b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.cpp
@@ -13,20 +13,22 @@
 
 PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE( wxWindow* parent, wxWindowID id, const wxPoint& pos, const wxSize& size, long style, const wxString& name ) : CALCULATOR_PANEL( parent, id, pos, size, style, name )
 {
-	wxBoxSizer* bSizer4;
-	bSizer4 = new wxBoxSizer( wxVERTICAL );
+	wxBoxSizer* bSizerWindow;
+	bSizerWindow = new wxBoxSizer( wxVERTICAL );
 
-	m_scrolledWindow1 = new wxScrolledWindow( this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxVSCROLL );
-	m_scrolledWindow1->SetScrollRate( 5, 5 );
-	wxBoxSizer* bSizeMain;
-	bSizeMain = new wxBoxSizer( wxVERTICAL );
+	m_scrolledWindow = new wxScrolledWindow( this, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxVSCROLL );
+	m_scrolledWindow->SetScrollRate( 5, 5 );
+	wxBoxSizer* bSizerMain;
+	bSizerMain = new wxBoxSizer( wxVERTICAL );
 
-	m_stTitle = new wxStaticText( m_scrolledWindow1, wxID_ANY, _("Insulation coordination for equipment within low-voltage supply systems"), wxDefaultPosition, wxDefaultSize, 0 );
+	m_stTitle = new wxStaticText( m_scrolledWindow, wxID_ANY, _("Insulation coordination for equipment within low-voltage supply systems"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_stTitle->Wrap( -1 );
-	bSizeMain->Add( m_stTitle, 0, wxALIGN_CENTER|wxALL, 15 );
+	m_stTitle->SetFont( wxFont( wxNORMAL_FONT->GetPointSize(), wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD, false, wxEmptyString ) );
+
+	bSizerMain->Add( m_stTitle, 0, wxALIGN_CENTER|wxALL, 5 );
 
 	wxStaticBoxSizer* sbSizerTop;
-	sbSizerTop = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow1, wxID_ANY, _("Determine the transient impulse voltage to withstand") ), wxHORIZONTAL );
+	sbSizerTop = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow, wxID_ANY, _("Determine the transient impulse voltage to withstand") ), wxHORIZONTAL );
 
 	wxBoxSizer* bSizerTopLeft;
 	bSizerTopLeft = new wxBoxSizer( wxHORIZONTAL );
@@ -42,8 +44,8 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	fgSizer111->Add( m_staticText5211, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
-	m_ratedVoltage1 = new wxTextCtrl( sbSizerTop->GetStaticBox(), wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0 );
-	fgSizer111->Add( m_ratedVoltage1, 0, wxALIGN_CENTER_VERTICAL|wxALL|wxEXPAND, 5 );
+	m_ratedVoltage = new wxTextCtrl( sbSizerTop->GetStaticBox(), wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, 0 );
+	fgSizer111->Add( m_ratedVoltage, 0, wxALIGN_CENTER_VERTICAL|wxALL|wxEXPAND, 5 );
 
 	m_staticText52112 = new wxStaticText( sbSizerTop->GetStaticBox(), wxID_ANY, _("V"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText52112->Wrap( -1 );
@@ -53,12 +55,13 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	m_staticText52111 = new wxStaticText( sbSizerTop->GetStaticBox(), wxID_ANY, _("Overvoltage category:"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText52111->Wrap( -1 );
-	m_staticText52111->SetToolTip( _("OVC I: Equipments with no direct connection to mains supply\n\nOVC II: Energy-consming equipment to be supplied from the fixed installation. (eg: appliances, potable tools, household loads). OVCIII applys if there are reliability and avaibility requirements\n\nOVC III :  Equipements in fixed installation with reliability and avaibility requirements. (eg: electrical switches, equipment for industrial use)\n\nOVC IV: Equipments at the origin of the installation (eg: electricity meters, primary overcurrent protection devices)") );
+	m_staticText52111->SetToolTip( _("OVC I: Equipments with no direct connection to mains supply\n\nOVC II: Energy-consuming equipment to be supplied from the fixed installation. (eg: appliances, portable tools, household loads). OVCIII applys if there are reliability and avaibility requirements\n\nOVC III :  Equipements in fixed installation with reliability and avaibility requirements. (eg: electrical switches, equipment for industrial use)\n\nOVC IV: Equipments at the origin of the installation (eg: electricity meters, primary overcurrent protection devices)") );
 
 	fgSizer111->Add( m_staticText52111, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
-	wxArrayString m_OVCchoiceChoices;
-	m_OVCchoice = new wxChoice( sbSizerTop->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_OVCchoiceChoices, 0 );
+	wxString m_OVCchoiceChoices[] = { _("OVC I"), _("OVC II"), _("OVC III"), _("OVC IV") };
+	int m_OVCchoiceNChoices = sizeof( m_OVCchoiceChoices ) / sizeof( wxString );
+	m_OVCchoice = new wxChoice( sbSizerTop->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_OVCchoiceNChoices, m_OVCchoiceChoices, 0 );
 	m_OVCchoice->SetSelection( 0 );
 	fgSizer111->Add( m_OVCchoice, 0, wxALL|wxEXPAND, 5 );
 
@@ -106,10 +109,10 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 	sbSizerTop->Add( bSizerTopRight, 1, wxEXPAND, 5 );
 
 
-	bSizeMain->Add( sbSizerTop, 0, wxALL|wxEXPAND, 15 );
+	bSizerMain->Add( sbSizerTop, 0, wxEXPAND|wxTOP|wxBOTTOM, 5 );
 
 	wxStaticBoxSizer* sbSizerMiddle;
-	sbSizerMiddle = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow1, wxID_ANY, _("Compute the clearance and creepage distances") ), wxHORIZONTAL );
+	sbSizerMiddle = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow, wxID_ANY, _("Compute the clearance and creepage distances") ), wxHORIZONTAL );
 
 	wxBoxSizer* bSizerMiddleLeft;
 	bSizerMiddleLeft = new wxBoxSizer( wxHORIZONTAL );
@@ -166,12 +169,13 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	m_staticText112 = new wxStaticText( sbSizerMiddle->GetStaticBox(), wxID_ANY, _("Type of insulation:"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText112->Wrap( -1 );
-	m_staticText112->SetToolTip( _("Functional: inuslation is necessary only for the functioning of the equipment\n\nBasic: Insulation of hazardous-live parts.\n\nReinforced: Single insulation that provides a degree of protection equivalent to a double insulation. ( which is two separate basic insulations, in case one of them fails  ).") );
+	m_staticText112->SetToolTip( _("Functional: insulation is necessary only for the functioning of the equipment\n\nBasic: Insulation of hazardous-live parts.\n\nReinforced: Single insulation that provides a degree of protection equivalent to a double insulation. ( which is two separate basic insulations, in case one of them fails  ).") );
 
 	fgSizer11->Add( m_staticText112, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
-	wxArrayString m_insulationTypeChoices;
-	m_insulationType = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_insulationTypeChoices, 0 );
+	wxString m_insulationTypeChoices[] = { _("Functional"), _("Basic"), _("Reinforced"), wxEmptyString, wxEmptyString };
+	int m_insulationTypeNChoices = sizeof( m_insulationTypeChoices ) / sizeof( wxString );
+	m_insulationType = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_insulationTypeNChoices, m_insulationTypeChoices, 0 );
 	m_insulationType->SetSelection( 0 );
 	fgSizer11->Add( m_insulationType, 0, wxALL|wxEXPAND, 5 );
 
@@ -184,9 +188,10 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	fgSizer11->Add( m_staticText52, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
-	wxArrayString m_pollutionDegreeChoices;
-	m_pollutionDegree = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_pollutionDegreeChoices, 0 );
-	m_pollutionDegree->SetSelection( 0 );
+	wxString m_pollutionDegreeChoices[] = { _("PD1"), _("PD2"), _("PD3"), _("PD4") };
+	int m_pollutionDegreeNChoices = sizeof( m_pollutionDegreeChoices ) / sizeof( wxString );
+	m_pollutionDegree = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_pollutionDegreeNChoices, m_pollutionDegreeChoices, 0 );
+	m_pollutionDegree->SetSelection( 1 );
 	fgSizer11->Add( m_pollutionDegree, 0, wxALL|wxEXPAND, 5 );
 
 
@@ -198,8 +203,9 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	fgSizer11->Add( m_materialGroupTxt, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
-	wxArrayString m_materialGroupChoices;
-	m_materialGroup = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_materialGroupChoices, 0 );
+	wxString m_materialGroupChoices[] = { _("I"), _("II"), _("IIIa"), _("IIIb") };
+	int m_materialGroupNChoices = sizeof( m_materialGroupChoices ) / sizeof( wxString );
+	m_materialGroup = new wxChoice( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, m_materialGroupNChoices, m_materialGroupChoices, 0 );
 	m_materialGroup->SetSelection( 0 );
 	fgSizer11->Add( m_materialGroup, 0, wxALL|wxEXPAND, 5 );
 
@@ -208,7 +214,7 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	m_staticText1112 = new wxStaticText( sbSizerMiddle->GetStaticBox(), wxID_ANY, _("PCB material:"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText1112->Wrap( -1 );
-	m_staticText1112->SetToolTip( _("Printed wiring mateiral can benefit of a creepage distance reduction for RMS voltages lower than 1000V") );
+	m_staticText1112->SetToolTip( _("Printed wiring material can benefit of a creepage distance reduction for RMS voltages lower than 1000V") );
 
 	fgSizer11->Add( m_staticText1112, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
@@ -220,7 +226,7 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 
 	m_staticText1112121 = new wxStaticText( sbSizerMiddle->GetStaticBox(), wxID_ANY, _("Max altitude:"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_staticText1112121->Wrap( -1 );
-	m_staticText1112121->SetToolTip( _("Coating and potting allows for clearange and creepace distances reduction.Not supported by the calculator.\n\nA coating that could easily delaminate in the lifespan of the product (such as a soldermask) should not be considered for a reduction.") );
+	m_staticText1112121->SetToolTip( _("Coating and potting allows for clearance and creepage distances reduction. Not supported by the calculator.\n\nA coating that could easily delaminate in the lifespan of the product (such as a soldermask) should not be considered for a reduction.") );
 
 	fgSizer11->Add( m_staticText1112121, 0, wxALIGN_CENTER_VERTICAL|wxALL, 5 );
 
@@ -314,13 +320,13 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 	bSizerBitmapHelp = new wxBoxSizer( wxVERTICAL );
 
 	m_staticline3 = new wxStaticLine( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, wxLI_HORIZONTAL );
-	bSizerBitmapHelp->Add( m_staticline3, 0, wxEXPAND | wxALL, 5 );
+	bSizerBitmapHelp->Add( m_staticline3, 0, wxEXPAND|wxRIGHT|wxLEFT, 5 );
 
 	wxBoxSizer* bSizerBitmap;
 	bSizerBitmap = new wxBoxSizer( wxHORIZONTAL );
 
 	m_creepageclearanceBitmap = new wxStaticBitmap( sbSizerMiddle->GetStaticBox(), wxID_ANY, wxNullBitmap, wxDefaultPosition, wxDefaultSize, 0 );
-	bSizerBitmap->Add( m_creepageclearanceBitmap, 0, wxALL, 5 );
+	bSizerBitmap->Add( m_creepageclearanceBitmap, 0, wxALL|wxALIGN_CENTER_VERTICAL, 5 );
 
 	m_stBitmapLegend = new wxStaticText( sbSizerMiddle->GetStaticBox(), wxID_ANY, _("solid: clearance\ndashed: creepage"), wxDefaultPosition, wxDefaultSize, 0 );
 	m_stBitmapLegend->Wrap( -1 );
@@ -336,38 +342,32 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 	sbSizerMiddle->Add( bSizerMiddleRight, 1, wxEXPAND, 5 );
 
 
-	bSizeMain->Add( sbSizerMiddle, 0, wxALL|wxEXPAND, 15 );
-
-	wxBoxSizer* bSizerBottom;
-	bSizerBottom = new wxBoxSizer( wxHORIZONTAL );
+	bSizerMain->Add( sbSizerMiddle, 0, wxEXPAND|wxTOP|wxBOTTOM, 5 );
 
-	wxStaticBoxSizer* sbSizer3;
-	sbSizer3 = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow1, wxID_ANY, _("Help") ), wxVERTICAL );
+	wxStaticBoxSizer* sbSizerBottom;
+	sbSizerBottom = new wxStaticBoxSizer( new wxStaticBox( m_scrolledWindow, wxID_ANY, _("Help") ), wxVERTICAL );
 
-	sbSizer3->SetMinSize( wxSize( -1,100 ) );
-	m_panelHelp = new HTML_WINDOW( sbSizer3->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, wxHW_SCROLLBAR_AUTO );
+	sbSizerBottom->SetMinSize( wxSize( -1,100 ) );
+	m_panelHelp = new HTML_WINDOW( sbSizerBottom->GetStaticBox(), wxID_ANY, wxDefaultPosition, wxDefaultSize, wxHW_SCROLLBAR_AUTO );
 	m_panelHelp->SetMinSize( wxSize( -1,-200 ) );
 
-	sbSizer3->Add( m_panelHelp, 1, wxBOTTOM|wxEXPAND|wxLEFT|wxRIGHT, 5 );
-
-
-	bSizerBottom->Add( sbSizer3, 1, wxEXPAND, 5 );
+	sbSizerBottom->Add( m_panelHelp, 1, wxBOTTOM|wxEXPAND|wxLEFT|wxRIGHT, 5 );
 
 
-	bSizeMain->Add( bSizerBottom, 1, wxEXPAND, 5 );
+	bSizerMain->Add( sbSizerBottom, 1, wxEXPAND, 5 );
 
 
-	m_scrolledWindow1->SetSizer( bSizeMain );
-	m_scrolledWindow1->Layout();
-	bSizeMain->Fit( m_scrolledWindow1 );
-	bSizer4->Add( m_scrolledWindow1, 1, wxEXPAND | wxALL, 5 );
+	m_scrolledWindow->SetSizer( bSizerMain );
+	m_scrolledWindow->Layout();
+	bSizerMain->Fit( m_scrolledWindow );
+	bSizerWindow->Add( m_scrolledWindow, 1, wxEXPAND | wxALL, 5 );
 
 
-	this->SetSizer( bSizer4 );
+	this->SetSizer( bSizerWindow );
 	this->Layout();
 
 	// Connect Events
-	m_ratedVoltage1->Connect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
+	m_ratedVoltage->Connect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
 	m_OVCchoice->Connect( wxEVT_COMMAND_CHOICE_SELECTED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
 	m_RMSVoltage->Connect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateClearanceCreepage ), NULL, this );
 	m_transientOvervoltage->Connect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateClearanceCreepage ), NULL, this );
@@ -382,7 +382,7 @@ PANEL_ELECTRICAL_SPACING_IEC60664_BASE::PANEL_ELECTRICAL_SPACING_IEC60664_BASE(
 PANEL_ELECTRICAL_SPACING_IEC60664_BASE::~PANEL_ELECTRICAL_SPACING_IEC60664_BASE()
 {
 	// Disconnect Events
-	m_ratedVoltage1->Disconnect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
+	m_ratedVoltage->Disconnect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
 	m_OVCchoice->Disconnect( wxEVT_COMMAND_CHOICE_SELECTED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateTransientImpulse ), NULL, this );
 	m_RMSVoltage->Disconnect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateClearanceCreepage ), NULL, this );
 	m_transientOvervoltage->Disconnect( wxEVT_COMMAND_TEXT_UPDATED, wxCommandEventHandler( PANEL_ELECTRICAL_SPACING_IEC60664_BASE::UpdateClearanceCreepage ), NULL, this );
diff --git a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.fbp b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.fbp
index 9e823ec546..6c5eec39bc 100644
--- a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.fbp
+++ b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.fbp
@@ -46,7 +46,7 @@
             <property name="minimum_size"></property>
             <property name="name">PANEL_ELECTRICAL_SPACING_IEC60664_BASE</property>
             <property name="pos"></property>
-            <property name="size">699,561</property>
+            <property name="size">669,561</property>
             <property name="subclass">CALCULATOR_PANEL; calculator_panels/calculator_panel.h; </property>
             <property name="tooltip"></property>
             <property name="two_step_creation">0</property>
@@ -55,7 +55,7 @@
             <property name="window_style">wxTAB_TRAVERSAL</property>
             <object class="wxBoxSizer" expanded="1">
                 <property name="minimum_size"></property>
-                <property name="name">bSizer4</property>
+                <property name="name">bSizerWindow</property>
                 <property name="orient">wxVERTICAL</property>
                 <property name="permission">none</property>
                 <object class="sizeritem" expanded="1">
@@ -98,7 +98,7 @@
                         <property name="minimize_button">0</property>
                         <property name="minimum_size"></property>
                         <property name="moveable">1</property>
-                        <property name="name">m_scrolledWindow1</property>
+                        <property name="name">m_scrolledWindow</property>
                         <property name="pane_border">1</property>
                         <property name="pane_position"></property>
                         <property name="pane_size"></property>
@@ -118,11 +118,11 @@
                         <property name="window_style">wxVSCROLL</property>
                         <object class="wxBoxSizer" expanded="1">
                             <property name="minimum_size"></property>
-                            <property name="name">bSizeMain</property>
+                            <property name="name">bSizerMain</property>
                             <property name="orient">wxVERTICAL</property>
                             <property name="permission">none</property>
                             <object class="sizeritem" expanded="1">
-                                <property name="border">15</property>
+                                <property name="border">5</property>
                                 <property name="flag">wxALIGN_CENTER|wxALL</property>
                                 <property name="proportion">0</property>
                                 <object class="wxStaticText" expanded="1">
@@ -150,7 +150,7 @@
                                     <property name="enabled">1</property>
                                     <property name="fg"></property>
                                     <property name="floatable">1</property>
-                                    <property name="font"></property>
+                                    <property name="font">,90,700,-1,70,0</property>
                                     <property name="gripper">0</property>
                                     <property name="hidden">0</property>
                                     <property name="id">wxID_ANY</property>
@@ -184,8 +184,8 @@
                                 </object>
                             </object>
                             <object class="sizeritem" expanded="1">
-                                <property name="border">15</property>
-                                <property name="flag">wxALL|wxEXPAND</property>
+                                <property name="border">5</property>
+                                <property name="flag">wxEXPAND|wxTOP|wxBOTTOM</property>
                                 <property name="proportion">0</property>
                                 <object class="wxStaticBoxSizer" expanded="1">
                                     <property name="id">wxID_ANY</property>
@@ -323,7 +323,7 @@
                                                             <property name="minimize_button">0</property>
                                                             <property name="minimum_size"></property>
                                                             <property name="moveable">1</property>
-                                                            <property name="name">m_ratedVoltage1</property>
+                                                            <property name="name">m_ratedVoltage</property>
                                                             <property name="pane_border">1</property>
                                                             <property name="pane_position"></property>
                                                             <property name="pane_size"></property>
@@ -465,7 +465,7 @@
                                                             <property name="style"></property>
                                                             <property name="subclass">; ; forward_declare</property>
                                                             <property name="toolbar_pane">0</property>
-                                                            <property name="tooltip">OVC I: Equipments with no direct connection to mains supply&#x0A;&#x0A;OVC II: Energy-consming equipment to be supplied from the fixed installation. (eg: appliances, potable tools, household loads). OVCIII applys if there are reliability and avaibility requirements&#x0A;&#x0A;OVC III :  Equipements in fixed installation with reliability and avaibility requirements. (eg: electrical switches, equipment for industrial use)&#x0A;&#x0A;OVC IV: Equipments at the origin of the installation (eg: electricity meters, primary overcurrent protection devices)</property>
+                                                            <property name="tooltip">OVC I: Equipments with no direct connection to mains supply&#x0A;&#x0A;OVC II: Energy-consuming equipment to be supplied from the fixed installation. (eg: appliances, portable tools, household loads). OVCIII applys if there are reliability and avaibility requirements&#x0A;&#x0A;OVC III :  Equipements in fixed installation with reliability and avaibility requirements. (eg: electrical switches, equipment for industrial use)&#x0A;&#x0A;OVC IV: Equipments at the origin of the installation (eg: electricity meters, primary overcurrent protection devices)</property>
                                                             <property name="window_extra_style"></property>
                                                             <property name="window_name"></property>
                                                             <property name="window_style"></property>
@@ -490,7 +490,7 @@
                                                             <property name="caption"></property>
                                                             <property name="caption_visible">1</property>
                                                             <property name="center_pane">0</property>
-                                                            <property name="choices"></property>
+                                                            <property name="choices">&quot;OVC I&quot; &quot;OVC II&quot; &quot;OVC III&quot; &quot;OVC IV&quot;</property>
                                                             <property name="close_button">1</property>
                                                             <property name="context_help"></property>
                                                             <property name="context_menu">1</property>
@@ -832,8 +832,8 @@
                                 </object>
                             </object>
                             <object class="sizeritem" expanded="1">
-                                <property name="border">15</property>
-                                <property name="flag">wxALL|wxEXPAND</property>
+                                <property name="border">5</property>
+                                <property name="flag">wxEXPAND|wxTOP|wxBOTTOM</property>
                                 <property name="proportion">0</property>
                                 <object class="wxStaticBoxSizer" expanded="1">
                                     <property name="id">wxID_ANY</property>
@@ -1493,7 +1493,7 @@
                                                             <property name="style"></property>
                                                             <property name="subclass">; ; forward_declare</property>
                                                             <property name="toolbar_pane">0</property>
-                                                            <property name="tooltip">Functional: inuslation is necessary only for the functioning of the equipment&#x0A;&#x0A;Basic: Insulation of hazardous-live parts.&#x0A;&#x0A;Reinforced: Single insulation that provides a degree of protection equivalent to a double insulation. ( which is two separate basic insulations, in case one of them fails  ).</property>
+                                                            <property name="tooltip">Functional: insulation is necessary only for the functioning of the equipment&#x0A;&#x0A;Basic: Insulation of hazardous-live parts.&#x0A;&#x0A;Reinforced: Single insulation that provides a degree of protection equivalent to a double insulation. ( which is two separate basic insulations, in case one of them fails  ).</property>
                                                             <property name="window_extra_style"></property>
                                                             <property name="window_name"></property>
                                                             <property name="window_style"></property>
@@ -1518,7 +1518,7 @@
                                                             <property name="caption"></property>
                                                             <property name="caption_visible">1</property>
                                                             <property name="center_pane">0</property>
-                                                            <property name="choices"></property>
+                                                            <property name="choices">&quot;Functional&quot; &quot;Basic&quot; &quot;Reinforced&quot; &quot;&quot; &quot;&quot;</property>
                                                             <property name="close_button">1</property>
                                                             <property name="context_help"></property>
                                                             <property name="context_menu">1</property>
@@ -1656,7 +1656,7 @@
                                                             <property name="caption"></property>
                                                             <property name="caption_visible">1</property>
                                                             <property name="center_pane">0</property>
-                                                            <property name="choices"></property>
+                                                            <property name="choices">&quot;PD1&quot; &quot;PD2&quot; &quot;PD3&quot; &quot;PD4&quot;</property>
                                                             <property name="close_button">1</property>
                                                             <property name="context_help"></property>
                                                             <property name="context_menu">1</property>
@@ -1687,7 +1687,7 @@
                                                             <property name="pin_button">1</property>
                                                             <property name="pos"></property>
                                                             <property name="resize">Resizable</property>
-                                                            <property name="selection">0</property>
+                                                            <property name="selection">1</property>
                                                             <property name="show">1</property>
                                                             <property name="size"></property>
                                                             <property name="style"></property>
@@ -1794,7 +1794,7 @@
                                                             <property name="caption"></property>
                                                             <property name="caption_visible">1</property>
                                                             <property name="center_pane">0</property>
-                                                            <property name="choices"></property>
+                                                            <property name="choices">&quot;I&quot; &quot;II&quot; &quot;IIIa&quot; &quot;IIIb&quot;</property>
                                                             <property name="close_button">1</property>
                                                             <property name="context_help"></property>
                                                             <property name="context_menu">1</property>
@@ -1907,7 +1907,7 @@
                                                             <property name="style"></property>
                                                             <property name="subclass">; ; forward_declare</property>
                                                             <property name="toolbar_pane">0</property>
-                                                            <property name="tooltip">Printed wiring mateiral can benefit of a creepage distance reduction for RMS voltages lower than 1000V</property>
+                                                            <property name="tooltip">Printed wiring material can benefit of a creepage distance reduction for RMS voltages lower than 1000V</property>
                                                             <property name="window_extra_style"></property>
                                                             <property name="window_name"></property>
                                                             <property name="window_style"></property>
@@ -2045,7 +2045,7 @@
                                                             <property name="style"></property>
                                                             <property name="subclass">; ; forward_declare</property>
                                                             <property name="toolbar_pane">0</property>
-                                                            <property name="tooltip">Coating and potting allows for clearange and creepace distances reduction.Not supported by the calculator.&#x0A;&#x0A;A coating that could easily delaminate in the lifespan of the product (such as a soldermask) should not be considered for a reduction.</property>
+                                                            <property name="tooltip">Coating and potting allows for clearance and creepage distances reduction. Not supported by the calculator.&#x0A;&#x0A;A coating that could easily delaminate in the lifespan of the product (such as a soldermask) should not be considered for a reduction.</property>
                                                             <property name="window_extra_style"></property>
                                                             <property name="window_name"></property>
                                                             <property name="window_style"></property>
@@ -2869,7 +2869,7 @@
                                                     <property name="permission">none</property>
                                                     <object class="sizeritem" expanded="1">
                                                         <property name="border">5</property>
-                                                        <property name="flag">wxEXPAND | wxALL</property>
+                                                        <property name="flag">wxEXPAND|wxRIGHT|wxLEFT</property>
                                                         <property name="proportion">0</property>
                                                         <object class="wxStaticLine" expanded="1">
                                                             <property name="BottomDockable">1</property>
@@ -2937,7 +2937,7 @@
                                                             <property name="permission">none</property>
                                                             <object class="sizeritem" expanded="0">
                                                                 <property name="border">5</property>
-                                                                <property name="flag">wxALL</property>
+                                                                <property name="flag">wxALL|wxALIGN_CENTER_VERTICAL</property>
                                                                 <property name="proportion">0</property>
                                                                 <object class="wxStaticBitmap" expanded="0">
                                                                     <property name="BottomDockable">1</property>
@@ -3068,82 +3068,71 @@
                                 <property name="border">5</property>
                                 <property name="flag">wxEXPAND</property>
                                 <property name="proportion">1</property>
-                                <object class="wxBoxSizer" expanded="1">
-                                    <property name="minimum_size"></property>
-                                    <property name="name">bSizerBottom</property>
-                                    <property name="orient">wxHORIZONTAL</property>
+                                <object class="wxStaticBoxSizer" expanded="1">
+                                    <property name="id">wxID_ANY</property>
+                                    <property name="label">Help</property>
+                                    <property name="minimum_size">-1,100</property>
+                                    <property name="name">sbSizerBottom</property>
+                                    <property name="orient">wxVERTICAL</property>
+                                    <property name="parent">1</property>
                                     <property name="permission">none</property>
-                                    <object class="sizeritem" expanded="1">
+                                    <object class="sizeritem" expanded="0">
                                         <property name="border">5</property>
-                                        <property name="flag">wxEXPAND</property>
+                                        <property name="flag">wxBOTTOM|wxEXPAND|wxLEFT|wxRIGHT</property>
                                         <property name="proportion">1</property>
-                                        <object class="wxStaticBoxSizer" expanded="1">
+                                        <object class="wxHtmlWindow" expanded="0">
+                                            <property name="BottomDockable">1</property>
+                                            <property name="LeftDockable">1</property>
+                                            <property name="RightDockable">1</property>
+                                            <property name="TopDockable">1</property>
+                                            <property name="aui_layer"></property>
+                                            <property name="aui_name"></property>
+                                            <property name="aui_position"></property>
+                                            <property name="aui_row"></property>
+                                            <property name="best_size"></property>
+                                            <property name="bg"></property>
+                                            <property name="caption"></property>
+                                            <property name="caption_visible">1</property>
+                                            <property name="center_pane">0</property>
+                                            <property name="close_button">1</property>
+                                            <property name="context_help"></property>
+                                            <property name="context_menu">1</property>
+                                            <property name="default_pane">0</property>
+                                            <property name="dock">Dock</property>
+                                            <property name="dock_fixed">0</property>
+                                            <property name="docking">Left</property>
+                                            <property name="drag_accept_files">0</property>
+                                            <property name="enabled">1</property>
+                                            <property name="fg"></property>
+                                            <property name="floatable">1</property>
+                                            <property name="font"></property>
+                                            <property name="gripper">0</property>
+                                            <property name="hidden">0</property>
                                             <property name="id">wxID_ANY</property>
-                                            <property name="label">Help</property>
-                                            <property name="minimum_size">-1,100</property>
-                                            <property name="name">sbSizer3</property>
-                                            <property name="orient">wxVERTICAL</property>
-                                            <property name="parent">1</property>
-                                            <property name="permission">none</property>
-                                            <object class="sizeritem" expanded="0">
-                                                <property name="border">5</property>
-                                                <property name="flag">wxBOTTOM|wxEXPAND|wxLEFT|wxRIGHT</property>
-                                                <property name="proportion">1</property>
-                                                <object class="wxHtmlWindow" expanded="0">
-                                                    <property name="BottomDockable">1</property>
-                                                    <property name="LeftDockable">1</property>
-                                                    <property name="RightDockable">1</property>
-                                                    <property name="TopDockable">1</property>
-                                                    <property name="aui_layer"></property>
-                                                    <property name="aui_name"></property>
-                                                    <property name="aui_position"></property>
-                                                    <property name="aui_row"></property>
-                                                    <property name="best_size"></property>
-                                                    <property name="bg"></property>
-                                                    <property name="caption"></property>
-                                                    <property name="caption_visible">1</property>
-                                                    <property name="center_pane">0</property>
-                                                    <property name="close_button">1</property>
-                                                    <property name="context_help"></property>
-                                                    <property name="context_menu">1</property>
-                                                    <property name="default_pane">0</property>
-                                                    <property name="dock">Dock</property>
-                                                    <property name="dock_fixed">0</property>
-                                                    <property name="docking">Left</property>
-                                                    <property name="drag_accept_files">0</property>
-                                                    <property name="enabled">1</property>
-                                                    <property name="fg"></property>
-                                                    <property name="floatable">1</property>
-                                                    <property name="font"></property>
-                                                    <property name="gripper">0</property>
-                                                    <property name="hidden">0</property>
-                                                    <property name="id">wxID_ANY</property>
-                                                    <property name="max_size"></property>
-                                                    <property name="maximize_button">0</property>
-                                                    <property name="maximum_size"></property>
-                                                    <property name="min_size">-1,100</property>
-                                                    <property name="minimize_button">0</property>
-                                                    <property name="minimum_size">-1,-200</property>
-                                                    <property name="moveable">1</property>
-                                                    <property name="name">m_panelHelp</property>
-                                                    <property name="pane_border">1</property>
-                                                    <property name="pane_position"></property>
-                                                    <property name="pane_size"></property>
-                                                    <property name="permission">protected</property>
-                                                    <property name="pin_button">1</property>
-                                                    <property name="pos"></property>
-                                                    <property name="resize">Resizable</property>
-                                                    <property name="show">1</property>
-                                                    <property name="size"></property>
-                                                    <property name="style">wxHW_SCROLLBAR_AUTO</property>
-                                                    <property name="subclass">HTML_WINDOW; html_window.h; forward_declare</property>
-                                                    <property name="toolbar_pane">0</property>
-                                                    <property name="tooltip"></property>
-                                                    <property name="window_extra_style"></property>
-                                                    <property name="window_name"></property>
-                                                    <property name="window_style"></property>
-                                                </object>
-                                            </object>
+                                            <property name="max_size"></property>
+                                            <property name="maximize_button">0</property>
+                                            <property name="maximum_size"></property>
+                                            <property name="min_size">-1,100</property>
+                                            <property name="minimize_button">0</property>
+                                            <property name="minimum_size">-1,-200</property>
+                                            <property name="moveable">1</property>
+                                            <property name="name">m_panelHelp</property>
+                                            <property name="pane_border">1</property>
+                                            <property name="pane_position"></property>
+                                            <property name="pane_size"></property>
+                                            <property name="permission">protected</property>
+                                            <property name="pin_button">1</property>
+                                            <property name="pos"></property>
+                                            <property name="resize">Resizable</property>
+                                            <property name="show">1</property>
+                                            <property name="size"></property>
+                                            <property name="style">wxHW_SCROLLBAR_AUTO</property>
+                                            <property name="subclass">HTML_WINDOW; html_window.h; forward_declare</property>
+                                            <property name="toolbar_pane">0</property>
+                                            <property name="tooltip"></property>
+                                            <property name="window_extra_style"></property>
+                                            <property name="window_name"></property>
+                                            <property name="window_style"></property>
                                         </object>
                                     </object>
                                 </object>
diff --git a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.h b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.h
index a1aa8889b1..8f5a2d9580 100644
--- a/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.h
+++ b/pcb_calculator/calculator_panels/panel_electrical_spacing_iec60664_base.h
@@ -44,10 +44,10 @@ class PANEL_ELECTRICAL_SPACING_IEC60664_BASE : public CALCULATOR_PANEL
 	private:
 
 	protected:
-		wxScrolledWindow* m_scrolledWindow1;
+		wxScrolledWindow* m_scrolledWindow;
 		wxStaticText* m_stTitle;
 		wxStaticText* m_staticText5211;
-		wxTextCtrl* m_ratedVoltage1;
+		wxTextCtrl* m_ratedVoltage;
 		wxStaticText* m_staticText52112;
 		wxStaticText* m_staticText52111;
 		wxChoice* m_OVCchoice;
@@ -97,7 +97,7 @@ class PANEL_ELECTRICAL_SPACING_IEC60664_BASE : public CALCULATOR_PANEL
 
 	public:
 
-		PANEL_ELECTRICAL_SPACING_IEC60664_BASE( wxWindow* parent, wxWindowID id = wxID_ANY, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize( 699,561 ), long style = wxTAB_TRAVERSAL, const wxString& name = wxEmptyString );
+		PANEL_ELECTRICAL_SPACING_IEC60664_BASE( wxWindow* parent, wxWindowID id = wxID_ANY, const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize( 669,561 ), long style = wxTAB_TRAVERSAL, const wxString& name = wxEmptyString );
 
 		~PANEL_ELECTRICAL_SPACING_IEC60664_BASE();