100 Amp Meter, 200 Amp Disconnect

56 year old home
Upgraded electrical system.
100 Amp Meter (listed as 15 Amp which was the test rating),
200 Amp Main Disconnect.
I will identify the Service Size as 100 Amps. This is sufficient for this home since it has no Air Cond, an all gas range, one electric water heater and one gas water heater, electric dryer, no pool, no spa, no whirlpool, gas furnace.

**The question is… **does the 100 Amp meter **actually restrict **the service to no more than 100 Amps?

Also, the bus bars to the main disconnect appear to be aluminum but I didn’t find any cu/al rating on the main disconnect. The panel is rated for use with aluminum but I didn’t see any markings on the main disconnect indicating it was also rated for Al. Some of the smaller breakers in the panel did indicate cu/al but they all had cu conductors.

Second question is… is the panel rating enough for it to be considered okay to have the aluminum connections? Or does the breaker need to indicate it as well?





The meter is not a limiting factor. The meter base may be, but it’s not definitive unless you check the conductor size, which is usually not possible.

I’m not sure I understand the second question.

A meter cannot restrict anything, nor can a meter base. If the meter base is rated at 100 amps and substantially more than 100 amps is pulled thru it for an extended period the lugs will overheat and the connections will degrade.

The panel is a UL listed assembly that comes assembled with the main breaker, there is not an issue there.

In rewording the question I think I answered my own question Jeff.

Since there are no markings directly on the main disconnect or on the main disconnect sticker that indicate Al is allowable…and the bar connections at the top and bottom of the main disconnect appear to be aluminum…I should I call it out for further evaluation.

My question originally was basically: Can aluminum be used if there are not Al markings on the disconnect itself when the panel door sticker indicates that Al may be used in the panel. My answer is no.

Please correct me if you feel otherwise.

Which may lead to arcing, heat, fire…right?

So if the main disconnect is 200 Amps isn’t this an issue based on what you state above?

If the main is rated at 200 and the meter base is not than yes it is an issue even though it will not cause a problem unless the service actually pulls more than 100 amps. But yes it is still wrong, if you are sure the meter base is only rated at 100 amps. We avoid this by installing a meter combo when upgrading.

I just looked at another photo and the base is rectangular which is indicative of 200 Amps. However the meter is still 100 Amps. Any problem?

The box on the right is empty… it was the old service for the knob and tube that has been upgraded.


That is a 200 amp meter combo. The meter appears to have a POCO locking ring on it. Were the POCO seals intact? Since the meter belongs to the POCO, maybe they will answer your concerns. It may not be correct, but utility companies don’t have to follow our rules. Or maybe they don’t know about the upgrade.

If you tell this story to the POCO they will tell you the meter is OK for 200a and spin you a yarn about what the 100a means. I have heard a couple.