Cummins 20GSBB-6714A ATS replacement

IJB

Member
Location
Seattle, WA
Occupation
Electrician
I am a residential electrical contractor in Seattle, WA and have never come across a Cummins generator. A client of mine lost a phase and I found it was lost in the ATS. I told them I don’t have a strong background in Cummins as I’ve always used Generac and found them a technician by calling Cummins directly.

The technicians have been horrible and weren’t going to pull a permit and scared my client off so they asked if I’d be willing to give it a go and just replace the whole transfer switch. I’m confident in following the schematics and everything I’m just unsure of which model to buy and if I’ll have access to everything I need through online distributors or big box stores.

The model number of the generator is 20GSBB-6714A which has been discontinued.

Does anyone have some insight on this subject? I tried uploading a picture of the ATS as I imagine some of you may have an easier solution then replacing the whole ATS. Power comes in on the top of the switch and has both legs present, then the switch says phase A on phase b off.

I appreciate any help on this subject, thank you!
 
What does "lost in the ATS" mean? In most ATSs, there isn't much that can happen other than a contact failing in the power switching device (contactors or solenoid switch). Might be a simple case of a bad contact, which might be replaceable. That'll be a lot easier and cheaper than replacing the ATS.

BTW, in many places a permit wouldn't be needed to simply repair a piece of equipment; might need to coordinate an outage with the PoCo through (does that need a permit in your area?).
 

IJB

Member
Location
Seattle, WA
Occupation
Electrician
What does "lost in the ATS" mean? In most ATSs, there isn't much that can happen other than a contact failing in the power switching device (contactors or solenoid switch). Might be a simple case of a bad contact, which might be replaceable. That'll be a lot easier and cheaper than replacing the ATS.

BTW, in many places a permit wouldn't be needed to simply repair a piece of equipment; might need to coordinate an outage with the PoCo through (does that need a permit in your area?).
The lugs at the top of the ATS (line) read 120 on each phase but the lugs on the bottom read 0 on one leg. I’ll be going there to temporarily bypass the ATS temporarily and I’ll test more, I didn’t stick around long since I had found a certified Cummins shop to help.

The technicians told her she needed a new ATS too. They way they treated her seems like it could easily have been an upsale. So yeah, definitely should have been permitted and coordinated with PoCo but they were going to just pull the meter themselves. Which is allowed in Seattle city limits but not where this specific job is located.
 
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