service upgrade

Old 02-04-02, 08:29 PM
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Question service upgrade

Location: Central TX
1960 house with Zinsco main panel

I want to have the service upgraded to 200amps to allow a larger panel (full!) for a future home-office remodel that will require several dedicated branch circuits (evil 8 amp laser printers!).

To my point: Very few of the branch circuits are grounded - will the electrian have to re-wire the entire house to upgrade the service or can he/she simply reconnect all the branch circuits as they are currently setup?

Also, any clue on the cost of this and the time that would be required? (i.e. how much "down-time" would I be looking at when the house would be without power - hours?/days?)


Old 02-04-02, 08:40 PM
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more questions from the orig. poster

Another option...

I have two full-height (or whatever Zinsco called them) breakers - the rest are twins(?). If I replace the two full's with twins, I would gain to branch circuits, right? (One 20-amp, one 15-amp currently)

Also, the range is on a double full-height 50amp breaker (assuming that's what the 240vac breakers look like) that are tied with a wire band. Can I replace that double-one with a twin 50-amp and have room for an extra 15-amp twin? (Meaning I would have 4 new circuits available...)

Would all this be okay? Or would it cause one of the bus bars to become too hot?

Thanks, again!

Old 02-05-02, 09:46 AM
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You can't "twin the range" it requires 240v power which it takes from each of the two phases in the panel On a twin breaker they use one pahse for two.
You may be able to use the twins on the other two to gain the room you need, but you must run compatible circuits to what you have to work with.
My opion is if you are that low on space in a panel and you wish to continue to run circuits then sometimes running a new subpanel might be a good idea
Old 02-05-02, 11:30 AM
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Okay, by "twin the range" I meant to say swapping the current breaker that's 1 1/2 inches with an RC38-50 which I believe is 3/4 inches - it's listed as "T&B RC38-50. 50AMP 2POLE 240V PLUG IN. GTE-SYLVANIA/ZINSCO/CHALLENGER/ T& B ETC.. PANELS." It looks like both of the hot slots on the bottom of the breaker attach to the bars - not just one - hence the 240V rating for the plug-in. Sorry, I has half-asleep when I wrote the questions last night. That should free up another 3/4" of space (enough for another twin) and 2 additional circuits... right?

By the way - I'm only adding an additional 8amp (max) of load to the entire house. I just want to run two dedicated lines to the office (one for a 7.5amp laser and one for an 8amp laser), since the lights that share the same branch circuit with the 7.5amp laser flicker when the laser cycles the fuser. While I'm in the panel, I plan on making sure all the neurals are tight to see it that might me causing part of the "flicker" problem. Freeing-up the additional space is for "future-proofing".... A dedicated circuit for all the Christmas lights comes to mind....



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