Eaton Logo

PD-NF and PD-RF Maintenance Mode

The PXR20 trip unit is available with ARMS as an optional feature. The PXR25 trip unit includes ARMS standard. ARMS stands for Arcflash Reduction Maintenance System, and is used interchangeably with the term "maintenance mode". 

The wiring diagrams have sample maintenance mode (ARMS) schematics.

If you are going to wire in a remote switch to pins 20-22, this switch needs to have logic level contacts (note that 24VDC should NOT be applied across 20-22 even though pin 22 is the negative 24VDC connection). An option for a 30mm padlockable switch with a blue knob uses these components:

  • E34VFBK6 – maintained two position knob, blue
  • 10250T53E – logic level contact block, 1NO
  • 10250TA38 – padlock hasp
    • This allows the customer to use a padlock to prevent other people from operating the switch
  • E34SP42 – OFF/ON legend plate

If you are going to wire a relay contact to pins 20-22 to enable ARMS, this relay needs to have logic level contacts. One option is the XR relays in Volume 7 Tab 3; these are available with gold plated contacts.

If you would like to have a contact to indicate when ARMS is enabled, one of the programmable relays needs to be programmed for "Maintenance Mode active". By default, relay 1 (pins 13-14) comes configured for maintenance mode. This can be changed in the menu systems or by using PXPM.