Okay, you've got a classic case of a panel aging and connections degrading, exacerbated by the high continuous load of an EV charger. Let's break down the situation and potential solutions

Diagnosis & Likely Causes
Overheating at the Breakers

This is the key symptom. The primary culprit is almost certainly loose connections. Loose connections create resistance, and resistance generates heat (I²R losses). The higher the current (like with the EV charger), the more pronounced the heating.

Quad Breakers

Quad breakers (two double-pole breakers in one slot) inherently concentrate load and connections in a small area. This makes them more susceptible to overheating issues, especially with older panels where busbar stabs might be slightly weakened.

EV Charger Load

EV chargers represent a very high, continuous load. This is far more stressful on a panel than occasional use appliances. A 9600-watt charger is drawing a significant amount of current continuously.

Aluminum Feeders

Aluminum conductors are prone to oxidation, which increases resistance at connections. This oxidation layer needs to be mitigated with proper preparation (cleaning, anti-oxidant compound) when making terminations.

Panel Age

Panels from the 70s have seen a lot of thermal cycling (heating and cooling) over the years. This can weaken busbar stabs, breaker spring tension, and wire connections.

ITE/Siemens Compatibility

Siemens is the correct replacement breaker for ITE/Gould/Siemens panels, but as you noted, they sometimes feel a little looser. This is because ITE used a slightly different geometry that wasn't quite as tightly toleranced.

Potential for Loose Connection at Main

The fact that multiple breakers are overheating could indicate a problem further upstream, like the main breaker connections, the meter connections, or even the service entrance conductors at the point where they enter the house.

Why Siemens Breakers May Feel Loose

You're right, Siemens breakers can feel a little less snug in older ITE panels. This is likely due to slight manufacturing differences over time. ITE may have had a slightly different tolerance or bus bar thickness. While Siemens breakers are generally considered compatible, the fit might not be as perfect as the original ITE breakers were (when they were new). This slightly looser fit contributes to the potential for loose connections and overheating.

Steps You've Taken and What to Do Next1. You've Swapped Some Breakers

Replacing the badly damaged breakers is a good start to try to keep the customers safe until you can remedy the full solution. However, simply swapping breakers without addressing the underlying cause (loose connections) is just a temporary fix. The new breakers will likely experience the same problems down the line.2.

You've Recommended a Panel Swap

This is the BEST long-term solution. It eliminates all the potential issues related to aging components, busbar corrosion, and questionable connections.3.

You've Recommended an Exterior Disconnect

This is also a good idea, especially with an EV charger. It provides a convenient and safe shut-off point for the EV charger circuit, and it can also act as a safety disconnect for the entire house.

Next Steps & Recommendations (Given the Customer's Budget Constraints) Priority #1: Thoroughly Inspect and Retorque EVERY Connection

This is the minimum you should do.

Turn off the main breaker! Safety first. Carefully Inspect

Look for signs of burning, discoloration, or corrosion on the busbars, breaker stabs, wires, and connections.

Retorque

Using a torque screwdriver or wrench, retorque every screw connection in the panel to the manufacturer's specified torque. This includes the main breaker lugs, the neutral bus, the ground bus, and all breaker connections.

Crucially, use an anti-oxidant compound (like Noalox or Penetrox) on aluminum connections before retorquing. Check Wire Insulation

Look for cracked or brittle wire insulation near the terminations. Overheating can degrade the insulation. If damaged, carefully trim the wire back to healthy insulation and re-terminate.

Check Wire Gauge

Verify that the wire gauge is appropriate for the breaker size.

Inspect and Retorque Meter Connections

Call the utility company and have them come out and inspect the meter base connections. This is a crucial step, as a loose connection at the meter can cause problems throughout the entire electrical system. Let them know you suspect a possible loose connection on the service.

Inspect and Retorque Main Breaker Connections

While the panel is de-energized, carefully inspect the main breaker connections. Retorque them to the manufacturer's specification. If the main breaker itself shows signs of damage, it should be replaced.

Consider Replacing Quad Breakers with Individual Breakers (If Possible)

If the panel layout and available spaces allow, replace the quad breakers with individual breakers. This reduces the concentration of load on single busbar stabs.

Derate EV Charger (Potentially)

If a panel swap isn't possible and overheating persists, consider derating the EV charger. This means reducing the maximum charging amperage. While it will slow down charging, it will reduce the continuous load on the panel. You can adjust the charging amperage in the EV charger settings or the EV's settings.

Offer a Phased Approach (If Budget is the Issue)

Explain to the homeowner that a panel swap is the best solution, but if that's not feasible right now, you can take a phased approach:1.

Phase 1

Thorough inspection, retorquing of all connections, and replacement of any damaged components.2.

Phase 2

(Later, when budget allows) Panel swap and exterior disconnect.

Documentation is Key

Document everything you do, including inspection findings, torque values, and any recommendations you make. This protects you from liability in the future.

Important Safety Considerations Working on electrical panels is dangerous. If you're not comfortable or qualified, hire a licensed electrician. Always de-energize the panel before working on it. Double-check that the power is off with a voltage tester. Wear appropriate personal protective equipment (PPE), including safety glasses and insulated gloves.By taking these steps, you can address the immediate overheating issue and provide the homeowner with a plan to improve the safety and reliability of their electrical system, even within budget constraints. Emphasize the importance of addressing the underlying problem and explain the risks of continuing to operate the panel in its current condition. Flag for review