# Generac Transfer Switch



## electricalwiz (Mar 12, 2011)

I have a customer (my uncle) who had a 7kw Generac generator that went bad. I am replacing it with a 10 kw. The exsitng transfer switch is rated for 100 amp. In the existing transfer switch their is connections for utility, load 23 and 194. I called Generac Customer service and they were no help because the existing tranfer switch does not have a model or serial number
Any ideas how to make this transfer switch work with the new generator


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## TOOL_5150 (Aug 27, 2007)

electricalwiz said:


> I have a customer (my uncle) who had a 7kw Generac generator that went bad. I am replacing it with a 10 kw. The exsitng transfer switch is rated for 100 amp. In the existing transfer switch their is connections for utility, load 23 and 194. I called Generac Customer service and they were no help because the existing tranfer switch does not have a model or serial number
> Any ideas how to make this transfer switch work with the new generator


hook it back up the way you un-hooked it.


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## electricalwiz (Mar 12, 2011)

TOOL_5150 said:


> hook it back up the way you un-hooked it.


The same terminals are not available on the new generator


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## ohiosparky99 (Nov 12, 2009)

Those sound like utility sense connections, may be able to find a connection labled T1 & T2 on the generator, possibly land them there if that's the case


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## electricalwiz (Mar 12, 2011)

ohiosparky99 said:


> Those sound like utility sense connections, may be able to find a connection labled T1 & T2 on the generator, possibly land them there if that's the case


I was thinking the same thing about the T1 & T2 being the utility
But not sure about the load and 23/194 terminals


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## nrp3 (Jan 24, 2009)

You have a new nexus 10 kw unit? You will be missing the T1 connection for powering the board. You need n1,n2, 23, 194, and T1. The first two are utility sense, the second are +194, -23 both for transfer, the third is for powering the control board/battery charger.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> You have a new nexus 10 kw unit? You will be missing the T1 connection for powering the board. You need n1,n2, 23, 194, and T1. The first two are utility sense, the second are +194, -23 both for transfer, the third is for powering the control board/battery charger.


Is there any way to make it work without ordering a new transfer switch
Are you a dealer


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## nrp3 (Jan 24, 2009)

I am a dealer/service guy. There probably is a way to do this as long as those other four terminals are available. I haven't done this myself. The new transfer switches will have a three terminal fuse block instead of the two fuse one you have. Its all about getting 120v for T1 from the right place, most likely from the output going to the breakers, not either input ie utility or generator feeds. That way T1 recieves 120v all the time regardless of the source. It needs to be fused just like n1,n2.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> I am a dealer/service guy. There probably is a way to do this as long as those other four terminals are available. I haven't done this myself. The new transfer switches will have a three terminal fuse block instead of the two fuse one you have. Its all about getting 120v for T1 from the right place, most likely from the output going to the breakers, not either input ie utility or generator feeds. That way T1 recieves 120v all the time regardless of the source. It needs to be fused just like n1,n2.[/quote
> 
> I know I had 6 conductors going to the genertor from the transfer switch
> 2 were utility, 2 were load, 2 were the 23 and 194
> ...


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## nrp3 (Jan 24, 2009)

Is this a whole house switch, ie just transfer mechanism, or does it have its own little load center built in? The other question I would ask is do you need a service rated switch or not. The RTSX is not service rated, the RTSD is. Looking at the lead times on the dealer site, that might be accurate. I am doing repairs and portables right now, had a long wait for Reliance manual transfer switches. As for control wires for these two switches, you would need an extra wire "0" if you want to be able to use the load shedding feature of these switches.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> Is this a whole house switch, ie just transfer mechanism, or does it have its own little load center built in? The other question I would ask is do you need a service rated switch or not. The RTSX is not service rated, the RTSD is. Looking at the lead times on the dealer site, that might be accurate. I am doing repairs and portables right now, had a long wait for Reliance manual transfer switches. As for control wires for these two switches, you would need an extra wire "0" if you want to be able to use the load shedding feature of these switches.


Transfer switch is by itself with a seperate panel for the generator, not service rated, no load shedding needed, the only thing on the genreator is some lights and a couple of frigs and freezers, tvs etc but no AC. 
will the RTSX100 work? I can order it from Home Depot and they normally get it to me quicker


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## nrp3 (Jan 24, 2009)

That switch should work just fine with a new 10k. Though you might be able to add :

http://www.zillerelectric.com/0G925...1&searchPage=2&searchRank=price&searchSize=12

and be good to go.


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## nrp3 (Jan 24, 2009)

Not using the load shedding won't hamper the operation, its a seperate module within the enclosure.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> That switch should work just fine with a new 10k. Though you might be able to add :
> 
> http://www.zillerelectric.com/0G925...1&searchPage=2&searchRank=price&searchSize=12
> 
> and be good to go.


that came with the generator


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> Not using the load shedding won't hamper the operation, its a seperate module within the enclosure.


Thanks for all your help
Generac cusomter service is terrible and would not answer any of questions about the exisitng transfer switch
I am gonna go ahead and order the new transfer switch


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## nrp3 (Jan 24, 2009)

Really, did you order that(part on website)? Never seen that come with a generator. Anyway, do you get what that kit does? That tab goes under one of the lugs that feeds your subpanel. The the little section of wire goes from the tab to the line side of the fuse holder. The load side of the fuse holder becomes T1 going to the T1 terminal in the generator. Once done, you should have n1,n2,T1,194, and 23 for controls. 0 will be unsused in this case.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> Really, did you order that(part on website)? Never seen that come with a generator. Anyway, do you get what that kit does? That tab goes under one of the lugs that feeds your subpanel. The the little section of wire goes from the tab to the line side of the fuse holder. The load side of the fuse holder becomes T1 going to the T1 terminal in the generator. Once done, you should have n1,n2,T1,194, and 23 for controls. 0 will be unsused in this case.


I have no idea what it is 
I did not order the generator, the existing generator went bad and since my uncle had a home waranty on the house, they replaced the generator. But that was it, the warranty company delivered it to his house and the washed their hands of it.
Let me get this straight, I feed the fuse from the line side of the emergency panel and the load goes to T1 on the generator


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## electricalwiz (Mar 12, 2011)

So if N1 and N2 are utility, and 23 and 194 are your positive and negative, and I can generate the T1 like you described, cant I then reuse the exisitng transfer switch
So on T1 you would have 120 volts, correct?


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## nrp3 (Jan 24, 2009)

As long as the square metal piece can be installed under the left hand lug feeding the subpanel, that's correct. That provides power to the battery charger and the nexus control board regardless of whether you are on generator power or utility power.

That's the idea of this, yes, to reuse what you have. Exactly, n1 and n2 are utility sensing. 194 is constant positive. 23 is grounded to operate the transfer relay (should be a little ice cube relay in transfer switch) T1 is 120v feed from the transfer mechanism itself.

Don't forget to upsize the output wiring of the generator for the increased amperage too.


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## nrp3 (Jan 24, 2009)

Oh, and one other thing, you may need to upsize the gas line too.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> As long as the square metal piece can be installed under the left hand lug feeding the subpanel, that's correct. That provides power to the battery charger and the nexus control board regardless of whether you are on generator power or utility power.
> 
> That's the idea of this, yes, to reuse what you have. Exactly, n1 and n2 are utility sensing. 194 is constant positive. 23 is grounded to operate the transfer relay (should be a little ice cube relay in transfer switch) T1 is 120v feed from the transfer mechanism itself.
> 
> Don't forget to upsize the output wiring of the generator for the increased amperage too.


What metal piece? the piece I have is shaped like a rectangle with a 1/4" hole in one end and slit in the other end, does not match the piece in the picture that you posted.
The original install actually used 100 amp SE cable, not SER. So I have to replace it, it is only a 7 foot run though


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> Oh, and one other thing, you may need to upsize the gas line too.


I have my plumber looking at that, it is actually propane


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## nrp3 (Jan 24, 2009)

I have their slide rule for nat gas/propane for calculating distance from source/size of gen if you need a reference.

As long as you can find a way to attach a fused line to the left hand lug on the transfer mechanism that feeds the subpanel, you should be fine. You know how it is, they change parts around over time. Though different, it may do the same thing.


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## electricalwiz (Mar 12, 2011)

This is what I was talking about, but it does notshow the metal piece

http://www.munroelectric.com/silver...&ID=,Fuses,Misc..Fuse.Accessories,Fuse.Blocks


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> I have their slide rule for nat gas/propane for calculating distance from source/size of gen if you need a reference.
> 
> As long as you can find a way to attach a fused line to the left hand lug on the transfer mechanism that feeds the subpanel, you should be fine. You know how it is, they change parts around over time. Though different, it may do the same thing.


I was just thinking of running a piece of wire to feed it
Why the left side opposed to the right side
The propane tank it only about 15 feet from the generator


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## nrp3 (Jan 24, 2009)

Hang in there, I'm eating dinner at the same time. I have a bare transfer mechanism that I will get out of the truck to show you where to hook that fuse block to.


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## nrp3 (Jan 24, 2009)

This is what you have, correct?


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## nrp3 (Jan 24, 2009)

This is where that connection would go(T1):


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## nrp3 (Jan 24, 2009)

This piece doesn't have the lugs. We have to remove the ones there to attach that piece shown in the website photo. Would it really matter, left or right, probably not, just that it goes with the label, T1.


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## electricalwiz (Mar 12, 2011)

nrp3 said:


> This is what you have, correct?


I think so, but i dont have the transfer switch in front of me


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## nrp3 (Jan 24, 2009)

According to our slide rule, 3/4 inch line is good for 70 feet for a 10kw on propane. Add 2.5 ft for each bend to your straight length.


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