older electrical....please help

Older electrical is not my forte…this is a house built in 1979. 1st pic is a 60 amp breaker labeled “main” on the panel cover. 2nd. pic clearly shows aluminum service cables for more than 60 amp service. Wish I had one of those gauges to test for size but it is clearly for at least 100 amp. The 3rd pic is the meter which says “type M-50” Hopefully someone can help me with determining the service amps. Also, does it look like the 60 amp main that is below the other breakers will not shut those top breakers off with the flip of the main switch? Thanks.

p.s. the label on the panel was ripped so i couldn’t see what the panel was rated for.

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Going out on a limb here, 60 amp service, split bus panel.


It looks like a split bus panel with the 60 amp 2 pole feeding the bottom section. The top section has room for 6 2 pole breakers or 12 single pole breakers. (either works for the 6 motions to turn off all power) The main lugs at the top are fed with what appears to be 4/0 aluminum SE cable. It is rated for 200 amps in a residential application. Generally when a panel is fed with SE cable it is usually a sub-panel setup and requires a separate equipment ground bar which is not visible. A pic of the bottom half of the panel will help tell The Rest of the Story…:shock:

Split bus - no single service disconnect. Service is disconnected by switching off the top four breakers.

The service capacity is dependant upon the SEC size.

the bottom half was just 15 and 20 amp breakers for branch.

so what i am guessing here is i can report 60 amp service because of the 60 amp ‘main’ breaker but upgrading would be simple by installing a larger ‘main’ breaker due to the 4/0 aluminum service wire. Since I don’t know what the panel is rated for, I think I will defer to an electrican to evaluate. thanks

also, that 60 amp breaker labeled ‘main’ could be the breaker that shuts off the bottom branch circuit breakers. they were all 15 & 20 amps. the wire that comes from the 60 amp breaker in pic#2 connects to the bus that houses all the branch breakers. So, would i be correct in reporting the following…“Appears to be 4/0 al. service cable which would be sufficient for 200 amp service but since the panel information is torn away, I am unable to rate the panel and therefore am unable to ascertain with any degree of certainty the amperage to the home. Recommend a qualified electrician to evaluate and make repairs as necessary.”

The 60 amp breaker is the lighting main, not the main for the service. There can be up to five more 2 pole breakers (mains) on the top for the heavy loads like HVAC, range, dryer etc, and still be compliant. With 4/0 AL, if the meter is rated for it, you do have a 200 amp service there.

I see you are in the Sun City West area. APS has run only 200 amp capable services underground for many years as far as I know. Overhead is another story, but underground it was always 200, or more for the McMansions.

This does not mean the original meter base had to be rated for 200 amps. Sometimes people will slap in a new 200 amp panel using an old meter base rated at only 100 amps.


It sounds as if you don’t understand the “split-bus” concept.

There is no single disconnect, so reporting that it is a 60 amp service would be wrong. The service capacity is limited by the service conductors, not the size of the breakers that have been installed.

You should report that “the service amperage could not be determined.”

As others have said, the 60 amp breaker labeled as “main,” is the shutoff for the lower portion of the bus - the general branch circuits or “lighting” circuits.

I understand. Like I said, older electrical is a weak spot of mine but it’s becoming clearer now. thanks again for the help.
p.s. i did report it as unable to determine amps.