Need to know what 45mm, 54mm, and 72mm pitch means
GV2 Manual Starters
IEC Contactors and Starters
The pitch is the spacing between slots. In order to select the correct pitch, total up the width of the device, plus any side mounted auxiliaries. Use the total width for selecting the proper pitch. The busbar pitch selection must be the same or greater than the sum of device and auxiliaries.