Okay, Dave, let's break down how to identify a compatible replacement main breaker for your panel. Based on the picture and the information you've provided, it's highly likely you have an ITE/Siemens panel.1. Identifying the Panel (Confirming ITE/Siemens)



Look for Markings

The most obvious place to start is looking very closely at the panel's labeling. Look for "ITE," "Siemens," "Murray," or even just a logo. The panel door, the panel box itself, and the breakers inside might all have identifying marks. In your photo, the breakers look like Siemens breakers. ITE bought out Siemens later. This is good and makes it easier to find the correct breaker.

Panel Model Number

Ideally, there will be a model number printed on the panel's label. It's often inside the panel door or on the box itself. Take a picture of the panel label! This model number is the most reliable way to determine the exact replacement breaker.

2. Determining the Breaker Specs (If you can't find the model number)

If you can't find the panel model number, you need to determine the following about the existing breaker:

Amperage (Amps)

This is the most critical number. It's printed on the breaker's handle (e.g., "100A," "150A," "200A"). Replacing it with a breaker of different amperage could be dangerous and violate code.

Voltage

Residential panels in the US are typically 120/240V. The breaker will be rated for this. It's almost certainly 240V, but confirm.

Number of Poles

This is likely a 2-pole breaker (meaning it takes up two vertical slots in the panel). The main breaker is usually a 2-pole.

Physical Size and Mounting Style

ITE/Siemens breakers have a specific design.

3. Finding a Replacement Breaker

Here's how to find a replacement once you have the info from steps 1 & 2:

Best Option: Find the Exact Replacement

If you can find the exact part number printed on the old breaker, this is the easiest and safest option. Search online retailers like Amazon, Home Depot, Lowe's, or specialized electrical supply houses for that part number. Also try eBay. Sometimes you can find new old stock or used breakers there.

Electrical Supply House

Your local electrical supply house is your best resource. Take a picture of the old breaker and the panel label with you. They can cross-reference the information and find a compatible replacement. They deal with this all the time.

Online Retailers (Carefully)

You can find breakers on Amazon, Home Depot, etc. However, double-check that the breaker is compatible with your ITE/Siemens panel. Read the specifications carefully.

Siemens Website

Siemens often has a compatibility lookup tool on their website. You can enter the panel model number, and it will list compatible breakers.

4. Important Safety Considerations and Recommendations



Safety First: Turn Off the Power! Before you do anything, turn off the main breaker feeding the panel. Use a voltage tester to confirm that the panel is de-energized. Qualified Electrician

Replacing a main breaker is not a job for an amateur.

I strongly recommend hiring a licensed electrician to do this work. Main breakers carry a lot of current, and incorrect installation can be dangerous and could cause a fire. As a GC, you're likely familiar with hiring subcontractors. This is a job for a pro. Code Compliance

Make sure the replacement breaker meets current electrical code requirements. The electrician will be able to ensure this.

Inspect the Panel

While the panel is open, have the electrician inspect the entire panel for any other signs of damage or corrosion.

Breaker Torque

Ensure the breaker is properly torqued when installed. This is a common cause of failures.

Troubleshooting the Surges (Beyond the Breaker)



Loose Connections

The surges could be caused by loose connections elsewhere in the panel or at the meter. An electrician will check these.

Neutral Connection

A loose or corroded neutral connection is a common cause of voltage fluctuations and surges. The electrician will pay special attention to this.

Outside the Panel

While the breaker is the obvious suspect, the problem could be outside the panel (e.g., at the meter, the service drop from the utility). If the electrician can't find the problem in the panel, they may need to contact the utility.

In summary: Get the panel's model number if you can find it. Otherwise, carefully document the amperage, voltage, and physical characteristics of the breaker. Contact a licensed electrician to replace the breaker and inspect the panel. Flag for review