What Panel Do I Have? (Find Your Generator Interlock Kit in 60 Seconds)
Most homeowners buy the wrong interlock kit because they guess on the panel brand. This guide helps you identify your panel fast, avoid mistakes, and find the right interlock setup.
Look for the brand, breaker style, and label inside the door.
Interlock kits are not universal.
The wrong kit may not fit your breaker spacing or panel model.
Step 1: Open the Panel Door
Start with the easiest thing: open the breaker panel door and look inside. You are not removing the cover. You are only checking visible information.
- Find the brand name on the label or door.
- Look for a model number inside the panel door.
- Check the shape and color of the breakers.
- Find the main breaker amperage, often 100A, 150A, or 200A.
Important: Do not remove the panel cover. This guide is for visual identification only.
Step 2: Identify the Brand
The big four panel brands in many U.S. homes are Square D, Eaton, Siemens, and GE. Here is how to tell them apart.
Square D
One of the most common residential panel brands. You may see Homeline or QO.
- Look for the Square D logo.
- QO breakers often have a small orange indicator window.
- Homeline is very common in newer homes.
Eaton
Another very common brand. Older labels may say Cutler-Hammer.
- Common types include BR and CH.
- CH breakers often have tan handles.
- Check the label closely for Eaton or Cutler-Hammer branding.
Siemens
Common in many modern residential installations and remodels.
- Look for a Siemens label.
- Often paired with QP style breakers.
- Model details are usually printed clearly inside the door.
GE / ABB
Still common in many homes, especially older installations.
- Look for GE or sometimes ABB branding.
- THQL breakers are commonly associated with GE panels.
- Older homes may still have a large GE installed base.
Extra Square D Reference
Square D panels are common enough that it helps to compare a second example image while identifying your setup.
Second Square D Example
Use this as a visual cross-check if your panel looks close to Square D but you want a second reference before buying an interlock kit.
Do not guess off one image
Some homeowners misidentify their panel by one quick glance. A second reference image helps reduce bad purchases and improves confidence before moving to the compatibility step.
Step 3: Watch for Older Panels
Some older panel brands are known for safety concerns or poor upgrade value. If you have one of these, pause before buying an interlock kit.
Federal Pacific (FPE / Stab-Lok)
These panels are widely known for safety concerns. If you identify a Federal Pacific panel, it is usually smarter to get professional guidance than force an interlock solution onto outdated equipment.
Zinsco
Zinsco panels are another older style with a poor reputation. In many cases, replacement makes more sense than trying to build around the old panel.
Step 4: Match the Right Interlock Kit
This is where people mess up. An interlock kit has to match more than just the brand name.
- Panel brand
- Panel model number
- Main breaker position
- Breaker spacing
- Amperage
That means a Square D kit does not automatically fit every Square D panel, and the same goes for Eaton, Siemens, and GE.
Quick Decision Guide
Square D
If you have Homeline, buy a Homeline-compatible interlock. If you have QO, buy a QO-specific kit.
Eaton
Make sure you know whether it is BR or CH. They are not the same.
Siemens
Confirm the panel label and model before buying. Siemens compatibility details matter.
GE / ABB
Check the exact model and breaker layout before ordering an interlock kit.
Still not sure?
Look inside the panel door, find the model number, and search it with the words interlock kit.
Example: Square D HOM 200A interlock kitFind the Right Interlock Kit
Once you know the panel brand and model, you can narrow down the right interlock option fast.
Choose your panel brand below, then verify the exact model, breaker layout, and compatibility before buying.
⚠️ Interlock kits are NOT universal. Always match your exact panel model and breaker layout before purchasing.
This guide is for general identification and educational purposes only. Always verify compatibility using the exact panel label and manufacturer specifications before purchasing or installing an interlock kit. If you are unsure, use a licensed electrician.