generac generator and cummins transfer switch

Automatic/Manual transfer switch repair, wiring & troubleshooting questions
andrew
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Hello:
I am an electrical contractor installing a guardian generac 22 kw nat gas gen set twinning it with a cummins RA100 transfer switch
Am having trouble getting it to work in auto mode.
The site is 20 miles away with no telephone service yet.
The generator is indicating several faults such as red light and yellow light
CDY error and battery charger not connected.
In manual I can have it start and transfer and shut down and transfer
in auto nothing
also when I disconnect the utility feed nothing happens

I did have it start onc ein auto and it transffferred but did not transfer back. .

any suggestions?

Andy
Chris
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I'm not very familiar with the Cummins gear, but most of their stuff is made for 2-wire start generators. What control wiring do you have running between the generator and the transfer switch?
Generac tech for over 12 years. I'm here to help!
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andrew
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good morning Chris
I have at least 7 control wires going to the generator.

Andy
Chris
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But what are they connected to at each end?
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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Birken Vogt
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This is an interesting problem.

I studied the manual for the switch and first off it says warranty void if used with anything other than a specific list of Cummins generators.

That aside, it appears that transfer switch terminals 3 - 7 could be hooked to the Generac transfer terminals.

Terminal 1 grounds when utility is lost so that I believe would be for 2 wire start opposite pin 4 which is generator signal ground.

Or you could ignore 2 wire start and add a pair of fuses for an N1/N2 signal to the generator.

Look at the manual and the switch and see if you agree.
andrew
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sorry everyone I incorrectly posted 0 and 194 connections, this is the way it is connected


Hello.
So here what I've done.
I installed a fuse block with two fuses in the transfer switch connected to the transfer switch mains and wired these 2 wires to the oil filter heater in the generator

from the generator N1 and N2 (yellow) are connected to the #1 and #2 transfer switch terminal
T1 (blue) is connected to the #6 transfer switch terminal
0 (black) is connected to the #4 transfer switch terminal
194(Red) is connected to the #7 transfer switch terminal
23 (white) is connected to the #3 transfer switch terminal

I have ordered a two wire start kit from Generac dealer,
could use some help explaining any jumpers and connections tht may be needed.
Cummins has a detail to connect a two wire generic start on page 6 of their transfer switch diagrams, but have concerns with the generac battery charger connections

Thanks
Andy
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Chris
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The generator itself only needs 2 things if being used in 2-wire start mode: A set of wires for the actual 2-wire start signal and the T1 120V charger power to keep the battery alive. Other than that, the generator will just come on when told to do so and the switch would be responsible for everything else.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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andrew
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Thanks Chris
I have the two wire kit from generac and am concerned about where to stick them in the transfer switch.
The cummins transfer switch is an RA112N3 100 amp single phase non service entrance type.
would have sent you a pdf except my computer doesn't like the file number I found it on line by searching owner manualsl with the above number

I think I am looking for a set of contacts that are not being used for anything else

Its minus 25 C.outside and I am going to site to try and sort this for my customer later this morning .
Andy
Chris
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The transfer switch should have a dedicated set of 2-wire start contacts since the controller in the switch does the thinking. I don't have that manual in front of me, but I'm sure it would be in there!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
andrew
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OK thanks Chris I will have to find them or put another relay in it.
Andy
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