A customer wanted me to check out this house he was going to buy,and the bank wanted to know if the wiring was knob&tube and the amps of the main service.So from the pole he had 120v.2 wire,single ph. So i went to see how many amps was the service and i saw a meter sitting by itself and next to it was a new looking disconnect box with a two pole 30amp breaker in it.One side of the breaker wasn't being used.I'm pretty sure this was a 60amp at one time so what do i tell the customer,it's a sixty amp or a 30amp main?
Old knob & tube service upgrade
- Thread starter zappy
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
electricalperson
Senior Member
- Location
- massachusetts
most old services ive worked on are 120v 30amp. thats what the one you are working on is. 60 amp services came along after
goldstar
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
It may very well have been a 60 amp service at one time (as far as the POCO was concerned) but once the 30 amp disconnect was installed it then became a 30 amp service. I'd be willing to bet that there was a fuse box with 6 fuses inside the home.
I saw my first 60 amp, 120 volt service last year. I was working for a plumber who was installing a new steam boiler. The original one ran off a mili-volt system and required no electricity. The new one required me to install a dedicated, 120 volt circuit. From what I remember there was more than 6 fuses in this panel but it had a 60 amp fused main disconnect. I was quite surprised to see this as the house was in a residential area that had both larger and remodeled homes where new or upgraded services were installed. This HO was just a hold-out from the old days. He'll have a tough time selling his house without an upgraded service.
I saw my first 60 amp, 120 volt service last year. I was working for a plumber who was installing a new steam boiler. The original one ran off a mili-volt system and required no electricity. The new one required me to install a dedicated, 120 volt circuit. From what I remember there was more than 6 fuses in this panel but it had a 60 amp fused main disconnect. I was quite surprised to see this as the house was in a residential area that had both larger and remodeled homes where new or upgraded services were installed. This HO was just a hold-out from the old days. He'll have a tough time selling his house without an upgraded service.
What size is the conductor in the riser? we still have some homes with the 30A service with 2 15A fuses, most of then had owners connect 8 or 10 circuits to the 2 fuses, no problem when you put a penny in the socket. Don't forget back in the 40's and 50's all you needed to be a resi electrician was a flashlight and a roll of tape.
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Buck Parrish
Senior Member
- Location
- NC & IN
I changed a service on an older house. That had something like you have described. The main circuit did not have a breaker on it in to the house. But it looked like it. The 30 on the outside was where they double tapped off the main for an ac unit.
So it looked like you we're shutting off power to the house. But it was just a disco for the ac.:smile:
Just curious , you did take the panel cover off , didn't you?:wink:
There wasn't a riser.The service drop hit a insulator right below the eve and taped onto the knob & tube,and the wires went into the attic.I talked to POCO about the service drop conductors connecting to the knob & tube and he said man thats a old 60amp service i bet.So thats why i asked my friends at mike holt:smile:
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