3 (easy) questions for electricians

[disney]

installing a generator transfer switch for my mom's; same one as installed by electricians at my place more than 5 years ago, but (currently) have three questions. First is there a minimum distance between the main breaker box and the transfer box? the meter and main box are about 4" apart, which is little more than whats needed to have a piece of 2" pvc with a threaded male piece glued to each end. 2nd) are the plastic bushings needed when plastic pvc is used? (bushing piece circled in pic) Third the electrician ran the (expensive) main utility power wire to the top of the transfer switch using several extra feet (per piece) of 2/0 wire, and then made the (cheap) 6 gauge gen wire at the bottom, is there a reason why I could not do it the other way? thanks in advance.

 

[YardBikeBob]

No, no, and no, IMHO.

 

[Tractor Seabee]

The utility wire has to be the same size all the way to the panel. This type system relies on the generator circuit breaker to protect the smaller wire which is not code compliant. It also requires that load shedding be done when on generator. I am surprised an "electrician" did that install. Proper way is to have a separate essential load panel for the generator load sized for that load and proper size breaker to protect the wire. There are kits you can install in most modern panels to do the transfer a lot cheaper than that switch. There are plenty of diagrams on how to do this on the internet. Just google "generator transfer switches".

Ron

 

[disney]

The utility wire has to be the same size all the way to the panel. This type system relies on the generator circuit breaker to protect the smaller wire which is not code compliant.".
Ron

So if you were to do it (with this transfer switch) you would run 2/0 to the generator inlet socket? I would be ok with that (yeah more $, but not much), but its not likely I can connect that thick wiring to a 30, or even 50amp inlet connector, unless I trim a lot of the copper strands, which i doubt is allowable.

Also her 'real' panel on the garage wall is recessed, into a wall less than 40" wide, so any generator sub panel would have to be mounted to a different wall (not desirable with how her garage is set up), and while not impossible, would make it more difficult. Also I paid less for those transfer switches than you might expect. My american made eaton was less than 300$ when I bought mine, but hers was a little more.

 

[stingray1]

1.no 2.yes 3.no

 

[Tractor Seabee]

I was misunderstood; only the utility side needs the 2/0. The generator side needs a wire size based on the circuit breaker protecting the wire from the Generator to the circuit breaker protecting the wire. Size the generator side to the largest connected load you would ever want to encounter. You may want to use a larger generator some day. Remember breakers protect the wire not the generator; it has its own overload protection installed by the manufacturer. Any jury rigged solutions are dangerous and non-code. Also wire sizing needs to be based on 125% of the connected load; such as a 20 breaker should only be loaded to 15 amps.

Ron

 

[rekees4300]

is there a reason why I could not do it the other way? thanks in advance.

I hired a professional electrician to install our transfer switch. Different strokes for different folks but I recommend you do the same. If project is done incorrectly, yourself and/or a repair lineman could be electrocuted. Ask yourself if the risk is worth it to save a few bucks.

 

[disney]

I am running 6ga thhn, rated 65a to the gen, current generator 30a, and planned gen is 50a, so she should be ok.

Thanks for the replay, and sorry for any misunderstanding on my part.

 

[disney]

I hired a professional electrician to install our transfer switch. Different strokes for different folks but I recommend you do the same. If project is done incorrectly, yourself and/or a repair lineman could be electrocuted. Ask yourself if the risk is worth it to save a few bucks.

When I had mine done; the 'professional' electricians charged their hourly per guy rate (I think it was 85$ then) as they waited for the inspector. so I paid 170+ per hour until the inspector showed up... more than two hours later.... would you pay 400+ for them to play on their smart phones, and eat lunch again? note that does not count the time it took them to do the actual work.

Regarding safety, with this type of switch it is impossible to feed power from generator back to the utility, or from utility into the generator, but I understand, and agree with you on safety.

 

[hr3]

One problem I see with the installer put the green bonding screw in place this would tell me that this is the first switch after the meter which would make it wrong. There has to be a breaker or fuses before it goes to the switch. If you look close at the label on the transfer switch I don't think you will find the markings for " Service rated transfer switch". But other than that being against the code it looks good. lol