Main panel size

[Stan Croenne]

Need a little help on main panel amperage. Did a 60 year old home yesterday. Outside meter is round type. # 4 copper leading to the main panel breaker. Main breaker is 100 amp. What would you rate this. I always struggle with the round exterior meter. I was told that that type of meter is a 60 amp meter. What would you say. 60 or a 100. Thanks, Stan

[Larry D. Kage]

Originally Posted by scroenne

Need a little help on main panel amperage. Did a 60 year old home yesterday. Outside meter is round type. # 4 copper leading to the main panel breaker. Main breaker is 100 amp. What would you rate this. I always struggle with the round exterior meter. I was told that that type of meter is a 60 amp meter. What would you say. 60 or a 100. Thanks, Stan

Probably 100 amp but what was the service panel rating?

[Robert Meier]

IMO, 100 main breaker, 100 amp panel, 100 amp condcutor = 100 amp service. What was the insulation type on the #4 AWG?

[Stan Croenne]

100 amp rating on service panel. Older gray woven cable covering. Appears to be original from the meter.

[Robert Meier]

Originally Posted by scroenne

100 amp rating on service panel. Older gray woven cable covering. Appears to be original from the meter.

So it's SE cable w/ #4 AWG copper condcutors? Should be Ok for 100 amps due to NEC Table 310.15(B)(6) which allows #4 AWG copper to be used for a 100 amp residential service. The reason I asked about the insulation is that 60 years ago type TW insulation was commonly used and that is one of the insulation types that is not permitted to use NEC table 310.15(B)(6) for ampacity sizing.