7210 24kw disconnecting white battery charging cable

[mygenbckup]

My 7210 24kw generator was installed in December 2021. I’ve noticed over the last three months it takes the generator longer to crank and start the engine about 4 to 5 seconds. About two months ago it overcranked during a brown out (short power outage). A 6 month oil change was already scheduled the generac service rep. , also had trouble starting the generator manually to warm up the oil and change it. It took him 3 times (due to overcranking) and then it finally started the engine. He didn’t even check the battery or charger and just left after the oil change after I told him of the starting issue. I was able to remove the battery and inspect the water levels and they all seemed low (but above the plates). I filled each cell with distilled water (since don’t have a battery charger I was not able to charge the battery before adding water but I was careful not to over fill and just fill to the lowest minimal level to avoid water expanding out of the battery later). I figured since the battery was connected to a charger inside the generator that he should be close to fully charged anyway. Anyway my mobile link app showed that the battery voltage before adding water was 13v and a few hours after adding water it now read 13.4v, so the water seems to have helped and the generator seems to be starting after about 3 seconds of cranking. I also checked the battery a day later after exercising the generator the previous day and there was no battery acid leakage due to the water I added. My question is upon the next time I need to remove the battery I will follow all the steps in the owners manual regarding the battery expect I want to skip “disconnecting the white charging cable”(because it is hard to get to) and just turn off my MLCB at my house(I also turned off the MLCB inside the generator and pulled the fuse and put generator in “off” mode at the control panel). Since no electricity in coming to my house due to house’s MLCB is now off, there should be no problem removing the battery for future inspections or replacement if I skip the step of disconnecting the white battery charging cable? Right? Also the 7210 Model has a “Smart Battery Charge” which mean’s: “Delivers charge to the battery only when needed at varying rates depending on outdoor air temperature. Compatible with lead acid and AGM-style batteries.” I believe the battery is charged using the electricity from my house’s Main Line Electrical input not a physical charging unit inside my generator.
So would it be safe to skip the step of disconnecting the white battery charging cable as long as I shut down the house’s MLCB since that would prevent any power going to the transfer switch and the generator? Attached is a picture of the white battery charging cable.

[mygenbckup]

My 7210 24kw generator was installed in December 2021. I’ve noticed over the last three months it takes the generator longer to crank and start the engine about 4 to 5 seconds. About two months ago it overcranked during a brown out (short power outage). A 6 month oil change was already scheduled the generac service rep. , also had trouble starting the generator manually to warm up the oil and change it. It took him 3 times (due to overcranking) and then it finally started the engine. He didn’t even check the battery or charger and just left after the oil change after I told him of the starting issue. I was able to remove the battery and inspect the water levels and they all seemed low (but above the plates). I filled each cell with distilled water (since don’t have a battery charger I was not able to charge the battery before adding water but I was careful not to over fill and just fill to the lowest minimal level to avoid water expanding out of the battery later). I figured since the battery was connected to a charger inside the generator that he should be close to fully charged anyway. Anyway my mobile link app showed that the battery voltage before adding water was 13v and a few hours after adding water it now read 13.4v, so the water seems to have helped and the generator seems to be starting after about 3 seconds of cranking. I also checked the battery a day later after exercising the generator the previous day and there was no battery acid leakage due to the water I added. My question is upon the next time I need to remove the battery I will follow all the steps in the owners manual regarding the battery expect I want to skip “disconnecting the white charging cable”(because it is hard to get to) and just turn off my MLCB at my house(I also turned off the MLCB inside the generator and pulled the fuse and put generator in “off” mode at the control panel). Since no electricity in coming to my house due to house’s MLCB is now off, there should be no problem removing the battery for future inspections or replacement if I skip the step of disconnecting the white battery charging cable? Right? Also the 7210 Model has a “Smart Battery Charge” which mean’s: “Delivers charge to the battery only when needed at varying rates depending on outdoor air temperature. Compatible with lead acid and AGM-style batteries.” I believe the battery is charged using the electricity from my house’s Main Line Electrical input not a physical charging unit inside my generator.
So would it be safe to skip the step of disconnecting the white battery charging cable as long as I shut down the house’s MLCB since that would prevent any power going to the transfer switch and the generator? Attached is a picture of the white battery charging cable.

[grsthegreat]

A much easier way , and not have to shut off power to house, is:

1. Turn generator to off
2. Open transfer case and disconnect the 9 wire molex connector, as it simply unplugs. This kills all utility power into generator

66CF9460-0EED-48B4-B9C5-CD8F77937911.jpeg (84.72 KiB) Viewed 2944 times

[mygenbckup]

Thank you for your answer. Someone from Generac suggested that to me also. But I’m concerned about the transfer switch and then opening the internal cover and being close to the deadly electrical wires nearby. If I turn off the electricity to my house through my main house circuit breaker that would shut down all the electricity coming from the power company into my house. I would assume that would mean no electricity would be going to the transfer switch or the generator? Right. Or would the transfer switch still be getting power from the electric company? I don’t know. But if the first scenario is true then I would not have to disconnect the white battery charger cable when working on the battery since I have shut down all the power to my house and also shut down the MLCB in the generator and pulled the fuse and put the generator in off mode? Right. Please let me know if you think I am safe in this regard. Thank you.

[grsthegreat]

If you first turn off the generator, not the generator breaker, but the generator controller. Then shut off the breaker inside the transfer switch you will kill all power going into generator.

Im not sure how your system is hooked up, but as long as your transfer switch has the large 200 amp breaker inside it, that will kill power feeding house and generator.

Now, i am assuming your setup has the transfer switch after the meter, and that the transfer switch then feeds the house panel and the generator. But your discription leads me to think that there may be a breaker before the transfer switch? Is this correct.

Turning off the main breaker within the house panel will not kill power going into the generator IF that panel is after the transfer switch.

Pictures would help

[mygenbckup]

The meter was pushed to the left from where it original was and the transfer switch was placed where the meter used to be. The main house breaker panel wiring now goes into the back bottom of the transfer switch. See pictures. Now I realize killing power at the house breaker panel does not kill any power at the meter or transfer switch. If I do what you say but add shutting down the MLCB inside the generator, put generator in off mode, pull the fuse and turn off the main switch inside the first part of the transfer switch, then that should shut down power to the generator and the battery right? Thanks

[grsthegreat]

Yes…you got it. The large breaker inside transfer switch is now your main point of service disconnect. Shut that off, you kill everything. But shut off gen first, or it will start up when you shut down breaker.

The BREAKER inside generator does not need to be shut off. It only protects the wires leading away from gen when gen is running. It does nothing about sending power into the generator. You only need to turn off the RED “OFF” button on controller.

You can also pull the small fuse on controller

Then remove negative wire first on battery, then positive terminal

Install positive terminal first on NEW battery, then negative.
Then install small spade fuse if removed.
Then turn on breaker in transfer switch
Then go to generator and follow instructions on screen. Reset time and follow instructions.
Lastly, place gen in AUTO mode.

[mygenbckup]

Thanks for your help. For clarification the owners manual says when doing general maintenance on the generator:
1. Set utility MLCB to off (open) ? Is this the main “Utility Service Disconnect” inside the transfer switch. Or is the utility MLCB my main house circuit breaker panel that shuts off power to the house. Just to be safe why can’t I shut down the MLCB inside the generator, then the Utility Service Disconnect inside the transfer switch and then lastly the circuit breaker in my electrical panel that shuts power to inside my house just to be safe when working on the generator?
Is the Utility Service Disconnect the same as the utility MLCB?
Thanks again.

[grsthegreat]

You can shut them all down if you want to, but you dont need to. The breaker in the transfer switch, when opened (off) kills all power from utility into house.

The MLCB in your case is the breaker inside the transfer switch..

[mygenbckup]

You wrote “The MLCB in your case is the breaker inside the transfer switch..”.

So when the manual says:
Proceed as follows to prepare unit for maintenance: 1. Set utility MLCB to OFF (OPEN). 2. Lift lid and set generator MLCB (generator discon-nect) to OFF (OPEN). 3. If running during a utility outage, allow generator to run and cool down for one minute with no load. 4. Press OFF button on controller. 5. Remove 7.5A fuse from control panel. 6. Remove front panel and intake side panel

In step 1 above “set utility MLCB to off”, that is the same as the “breaker switch” (or Utility Service Disconnect-see picture) inside my transfer box? Right?