Generator Interlock Kit for Eaton Panels
The Eaton generator interlock kit you need depends on whether your panel is a BR or a CH load center, whether it's a plug-on neutral model, and which main breaker it uses. Eaton sells its own mechanical interlocks for both lines, so read the panel label and the main breaker before you order anything.
Find the kit for your panel
BR or CH: tell them apart first
Eaton has two residential lines, and their breakers don't swap.
- BR is the common, budget line. The breakers are wider, with black handles.
- CH is the premium line, sold under the Cutler-Hammer name for decades. CH breakers are narrower, and many residential CH panels use tan-handle breakers (GenInterlock even sorts its CH kits by "tan handle" panels).
The panel label inside the door names the type. If the label is gone, the breakers themselves say BR or CH on the handle or the side. One more thing to note: newer panels from both lines come in plug-on neutral (PON) versions, where breakers clip onto a neutral rail instead of using a white pigtail wire. Eaton makes separate interlocks for those.
Eaton's own interlock kits
These are the catalog numbers Eaton lists on its product pages.
| Kit | Panel | Main breaker | Rating |
|---|---|---|---|
| BRMIKCSR | BR load centers | CSR type main (check spec sheet) | Not listed on the product page |
| BRPMIKCSR | Plug-on neutral BR load centers | CSR or CSH main | 225 A |
| BRMIKBR | BR back-fed load centers | Back-fed main breaker | Not listed on the product page |
| CHMIKCSR | CH load centers | CSR or CSH main | 225 A |
| CHPMIKCSR | Plug-on neutral CH load centers | CSR or CSH main | 225 A |
Eaton's pages for the BRMIKCSR, BRMIKBR and CHMIKCSR list them as UL listed. A "back-fed" BR panel is one where the main breaker sits down in the branch spaces, held by a retainer, rather than in a separate main compartment at the top. That's what the BRMIKBR is for.
Eaton's product page for the BRMIKCSR isn't fully consistent about which main breakers it covers, so pull the spec sheet linked from that page and match it to the catalog number printed on your main breaker.
When the Eaton kit doesn't fit
Older panels, meter-main combos and panels with the main at the bottom often don't match the factory kits. Aftermarket makers fill that gap. GenInterlock, for one, lists separate kits for BR panels made before and after a 2019 layout change, so the panel's age decides which one fits. It also lists kits for CH panels with the main on the bottom, CH and BR meter mains, and vertical-throw mains.
If you go aftermarket, buy a kit that's listed by a testing lab and comes with written instructions. Interlock Technologies says its kits are MET listed to UL standards. An inspector will want to see a listed product installed to its instructions, not a homemade plate.
Parts you need besides the kit
The interlock is only the lockout plate. The full setup also needs:
- A two-pole back-fed breaker of the same type as your panel (BR in a BR panel, CH in a CH panel). Interlock Technologies says the breaker style must match the panel.
- A hold-down or retainer for that breaker, since a back-fed breaker can't rely on the bus clip alone.
- An outdoor power inlet box and a generator cord rated for your generator's outlet.
For sizing, Interlock Technologies says a 30 amp back-feed breaker and inlet suit generators up to 8,000 watts, and larger units get a 50 amp setup. The generator's own manual has the final word on its largest outlet.
What the electrician does
The electrician mounts the plate between the main and the generator breaker, installs the retainer, runs wire from that breaker to the inlet box outside, and labels the panel. The plate lets only one of the two breakers be on at a time. Most of the work is the inlet run, not the plate, and the plate itself takes minutes once it's matched to the panel.
FAQ
Is a generator interlock kit legal?
Yes, when it's a listed kit installed to its instructions, with a permit where your town requires one. Interlock Technologies says its kits meet the NEC rules for optional standby systems. Check with your local building department before the work starts, because some places add their own rules.
How much does it cost to install an interlock kit on a generator?
The kit is the cheap part. Most of the bill is the electrician's labor to run the inlet box, the back-fed breaker, the cord and the permit. Get two written quotes that list each of those items separately.
Can I install my own interlock kit?
Some homeowners do, but it means working inside an energized panel, and many towns require a licensed electrician or a homeowner permit plus inspection. GenInterlock, which sells these kits, says electrical equipment should be installed by qualified, licensed people. We agree.
Which is better, a transfer switch or interlock kit?
An interlock costs less and lets you power any circuit in the panel, as long as you manage the load by hand. A transfer switch limits you to the circuits wired into it but makes switching simpler. For a portable generator, an interlock is usually the better value.
Sources
- EatonBRMIKCSR BR mechanical interlock kit (opens in a new tab)
- EatonBRMIKBR BR mechanical interlock kit for backfed loadcenters (opens in a new tab)
- EatonBRPMIKCSR BR plug-on neutral interlock (opens in a new tab)
- EatonCHMIKCSR CH mechanical interlock kit (opens in a new tab)
- EatonCHPMIKCSR CH plug-on neutral mechanical interlock (opens in a new tab)
- GenInterlockEaton and Cutler-Hammer generator interlock kits (opens in a new tab)
- Interlock TechnologiesInterlock kit FAQs (opens in a new tab)