Generator Interlock Kit for Cutler-Hammer Panels

Cutler-Hammer, Eaton, CH and BR: sorting out the names

Older panels say Cutler-Hammer on the label. Newer ones say Eaton. Both names cover the same two residential lines:

• CH, the premium line. Many residential CH panels use tan-handle breakers, and GenInterlock sorts some of its CH kits by "tan handle" panels.
• BR, the more common line, with black handles and wider breakers.

The two don't share breakers, and they don't share interlock kits. Check the panel label inside the door or the breaker handles before you shop. Then look at where the main breaker is: top of the panel, bottom of the panel, or down in the branch spaces with a retainer (a back-fed main).

Factory kits for CH panels

Eaton lists two mechanical interlocks for CH load centers.

The CHMIKCSR is UL listed on Eaton's page. If your CH panel has a plug-on neutral rail (breakers clip onto a neutral bar and have no white pigtail), you want the CHPMIKCSR instead.

Factory kits for Cutler-Hammer BR panels

For BR panels Eaton lists the BRPMIKCSR for plug-on neutral BR load centers with a CSR or CSH main, rated 225 A, and the BRMIKBR for BR back-fed load centers. Our Eaton interlock kit page covers the BR kits in more detail.

Older Cutler-Hammer panels

This is where most Cutler-Hammer owners end up, because a lot of these panels were installed decades ago and don't match a current Eaton catalog number. GenInterlock lists kits for several older CH layouts:

• CH panels made before 2019, sold separately from its plug-on neutral CH kit for later panels.
• CH panels with the main breaker at the bottom.
• CH meter-main panels with a single row of tan-handle breakers.
• Vertical-throw main panels, where the main handle moves up and down instead of side to side.

GenInterlock also says BR panel layouts changed in 2019, and it sells separate pre-2019 and post-2019 BR kits. So the year on the panel label matters as much as the brand.

Whatever you buy, it should be listed by a testing lab and come with instructions. Interlock Technologies says its kits are MET listed to UL standards. Inspectors look for that.

The rest of the hookup

The kit is only the lockout plate. You'll also need a two-pole back-fed breaker that matches the panel line (Interlock Technologies says the breaker style must match the panel), a retainer to hold it down, an outdoor inlet box, and a generator cord.

Interlock Technologies pairs a 30 amp back-feed breaker and inlet with generators up to 8,000 watts, and a 50 amp setup with larger units. Check your generator's manual for the outlet it actually has, since the cord and inlet have to match it.

The panel cover usually needs to be drilled or slotted for the plate, and the back-fed breaker goes in a specific position next to the main. That position is set by the kit, not by where you have an empty slot, so an electrician may need to move a branch circuit or two.