Cummins 20KW Generator low voltage wiring

[MGRABHAM]

Hello,
I am also having trouble mapping the DC wiring TB4 1-9 from the Cummins ATS RSS 200-6869 (no controller model) to the Cummins GenSet CH20N6H (RS20AE) labeled TB1 thru TB9. Thank you.

 

[hillbilly1]

The Cummins generator is far superior to the Generac’s, but their wiring diagrams are the worst. They have started giving a cheat sheet that simplifies which diagram to use now. I tried to find it, but my truck is mess right now, so it is buried in it somewhere. Here is some pictures of the basic controls, if you are doing the load shedding, you will need more. This is for the service entrance rated switch. Don’t forget to remove the bond jumper in the switch if you are not using it as the service disconnect.

 

[MGRABHAM]

Hello, thank you. Your picture seems to illustrate a TB2 terminal block therefore it has a controller within this transfer switch that you illustrated. My Transfer Switch is a RSS 200-6869 no controller with a TB-4 terminal block with 1-9. I need help mapping the TB-4 wires to the genetator TB set 1 thru 9 at the generator.

 

[hillbilly1]

That TS says it does have a controller and a battery charger, according to Cummins literature, but is discontinued. Do you have a picture of the TS terminal strip?

 

[cadpoint]

Hillbilly is that an Amp fuse in the first picture?

 

[hillbilly1]

Hillbilly is that an Amp fuse in the first picture?

On the terminal strip? No, it’s a jumper they supplied with the switch. I will have to clean my truck out and find that diagram. I’ve put two of them in this month. They are a little more complicated to install because they are not designed to be installed by a homeowner like Generac. Load shedding is all hardwire from the generator.

 

[MGRABHAM]

That TS says it does have a controller and a battery charger, according to Cummins literature, but is discontinued. Do you have a picture of the TS terminal strip?

Hello,
Here's a picture of the ATS RSS 200 low voltage TB4.

 

[MGRABHAM]

Here's a picture of my Cummins Onan service entrance RSS transfer switch without controller model RSS200-6869. The TB4 terminal is located at bottom on the left. Thanks.

 

[hillbilly1]

Looks like it will be wired the same, but may or may not need the jumper. I think the SE switches do require it. I think the switch position outputs are not needed unless you have a remote annunciation panel. If I can find what I have on it, I will post it.

 

[hillbilly1]

Here is the cheat sheet.

 

[MGRABHAM]

Do you think that the ATS illustration on the right for the TB4 connections RA200SE will work for my RSS200SE transfer switch?

 

[hillbilly1]

Seems to be labeled the same. Looks like the same switch I’ve been putting in, but yours has the charger ( black box above the terminal block) in the switch instead of the generator. They have the charger and alternator heater built into the generator now. (The 120 volt circuit that’s called for)

 

[MGRABHAM]

I agree, only one other difference the RA200SE requires that jumper on TB4 between 3 & 4, the RSS200SE does not appear to need it. I can try it without then add it if needed.

 

[hillbilly1]

Yeah, I think that jumper just provides the common -12 vdc to K1.

 

[MGRABHAM]

Well no luck, turned of utility power with genset remote & standby enabled, this config. TB4-1 tied to genset TB6-ATS,
TB-4 tied to genset TB7-gnd with & without jumper to TB-3, TB4-7 tied to genset TB5--TB4-7.

 

[hillbilly1]

Did K1 light up? Did the generator start, but not transfer?

 

[hillbilly1]

Meant to mark up the picture showing K1! Sorry!

 

[MGRABHAM]

Not sure about K1, however the generator did not even start when I cut utility power.

 

[hillbilly1]

With utility off, see if you get 12 vdc between 1 and 4? Should be zero with utility on.

 

[hillbilly1]

Scratch that, it’s 12 vdc WITH utility on! Sorry!