Maintenance Bypass

Power distribution

Maintenance bypass

A maintenance bypass lets you move the load from the UPS to utility power with one switch, so the UPS can be repaired or replaced while the connected equipment keeps running. Switch back and the load is protected by the UPS again. The XBDM plugs in with supplied cords and adds outlets; the XBDM HW is hardwired through terminal blocks.

Compare models

ModelConnectionsRatingsTransfer timeOutletsMounting
XBDMSupplied cords15, 20, 30A at 120V; 16A at 208/230V4-8 msUp to 101U rack, horizontal or vertical
XBDM HWHardwired terminal blocks15, 20, 30A at 120VAC; 63A at 230VAC8 ms (63A: make-before-break)Six 5-15R on 15A and 20A modelsWall or 19-inch rack, hardware included
The M90S and X90 modular UPS include a maintenance bypass, so they don’t need a separate module. The XBDM is not recommended for UPS with switched output receptacles.

How to choose

If you needStart with
A plug-in bypass for a 120V UPS up to 1500 VAXBDM-1015LV
The same for a 2000 or 3000 VA UPSXBDM-1020LV or XBDM-1030LV
A 208/230V UPS, up to 16AXBDM1020HV1 or XBDM1020HV2
A bypass wired into the electrical panel, 120VXBDM HW, 15, 20 or 30A
A higher-capacity UPS with a bypass interlock, such as the P91 5-10 kVAXBDM-HW63 (confirm interlock support for your model)
A UPS with bypass built inM90S or X90 modular UPS

Frequently asked questions

What does a maintenance bypass do?
It switches the load from the UPS output to utility power so the UPS can be turned off, serviced or replaced without shutting down the equipment. When the work is done, the switch returns the load to the UPS.
Is the load protected while in bypass?
The load keeps running on utility power and stays surge protected on the XBDM and on the 15A and 20A XBDM HW, but it has no battery backup until the UPS is back in the circuit. Keep the bypass period short.
XBDM or XBDM HW?
The XBDM plugs in with supplied cords and adds up to 10 outlets in a 1U enclosure. The XBDM HW connects through terminal blocks for hardwired installations, and the 63A model adds make-before-break transfer with a static-switch interlock.
Will the XBDM work with any UPS?
Match the XBDM model to the UPS rating and voltage. It is not recommended for UPS with switched output receptacles. Alternate versions are available for the P91 5-10 kVA.