# Home backup hits a snag.



## thehandyman1957 (Feb 11, 2017)

Hello all, first thing I should say is thank you for this forum and to all those who might be able to help.

I live in AZ and purchased a Generac Primepact 66LP (propane) generator for a backup system on my property.
It runs well and I finally got everything hooked up and wired in. 

This generator came out of a motor home and as I found out today, is not actually a 240 generator 
but two 120 legs at 30 amps each for a total wattage of 6600. It was designed for running in a 50 amp coach 
and running two 120 roof top AC's at the same time.

It shows 120 at each leg when testing from the neutral or ground to each leg. But leg to leg is zero.

I had purchased this to run my well pump and central air conditioning when the power goes out in monsoon season.
My central air requires 240v at 17 amps. 

I live in a 5th wheel and everything in the house works including the swamp cooler as it is only using one leg at 30 amps.

And now I'm in a pickle. My genius electronic friend said to find a voltage transformer that would convert the two 120 legs to 240 but looking online, I can't find anything that would take two 120 legs to 240 
but only one 120 leg to 240.

Does anyone have any suggestions?


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## Osviur (Sep 7, 2015)

Hi thehandyman1957,

It seems like one of the power coils were inverted. Let's see: This generator has two coils, each of them produces 120 volts. You can connect them in series ( as from factory), being the junction point the neutral. From this point to any of the 2 terminals will obtain 120 volts, and from extreme to extreme (end to end) 120 + 120 = 240 volts. But if you invert any one of the coils, ( phase inverting) you will obtain exactly what you are measuring 120 volts between neutral and each extreme but 0 volts between extremes because they are in phase. It means that at any instant the voltage in both terminals will be exactly at the same level, giving as result a difference of 0 volts between both terminals.

So the solution is very simple, if this is the case, just invert One of the coil terminals coming from the stator to the power connector, in this way: 
Before: a bnc d After: b anc d
Being a and b terminals, of coil 1 and c and d, terminals of coil 2, n is neutral.

I hope this help you.


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## thehandyman1957 (Feb 11, 2017)

Osviur, you are indeed correct. After seeing your reply I dug into the owners manual and found the exact instructions on 
page 6.

It took me about 40 minutes to get it all to where it needed to be and after testing it indeed showed 239 across both legs.

I tested it on both the central AC and then the well pump (separate of course) and both worked flawlessly :tango_face_grin:

Thank you for your reply and I will mark this as fixed.:tango_face_wink:


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## thehandyman1957 (Feb 11, 2017)

Well it seems I'm not allowed to edit any post so I'm not sure how to mark as fixed.


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## Osviur (Sep 7, 2015)

You are welcome thehandyman1957 and I am happy.


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