Hi and thank you to whoever reads this,
I'm back on the forum today after a hiatus. I have no recall as to where I've been, life is passing by like a mighty river. But I'm getting the Beast, as I call it, ready to travel back home to NY this summer. So - I've updated my older topic about a new LP gas tank, that's a separate post from this one, and I have this new question:

My original Norcold does not run on the 120V A/C when the generator is running, due to problems many of you have described, that the generator does not provide stable enough Hz output (as this layman would say it). And in this heat, I have the generator running even while driving to power the A/C.

It's been recommended on several topics that a very good solution is to just run the refrigerator only on 12V D/C, which is what I want to do. But none of the topics I've read describe how to disconnect the refrigerator from 120V A/C in my case, because I do not have a regular A/C plug coming out of the refrigerator into a regular 120V A/C outlet. I've looked in the cabinet area under the refrigerator and there's only the vacuum plug into an outlet. I've looked behind the vent under the refrigerator and only see a main power cord coming down from the refrigerator into two boxes, one being labeled a transformer, the other box is not labeled. I also looked where the water heater is plugged in and it's only the water heater plugged into that outlet.

I'm wondering if the wiring behind the vent under the refrigerator is the place to disconnect it from 120V A/C, and if so how, and if so, can I with novice electrical skills do the job; there aint much room in there to work, so God willing, it's an easy task.

Anyone know which connectors or wires to dork with to disconnect the refrigerator from 120V A/C please?

Thank you.
david

...You may be better to consider running the fridge off an inverter into its 120V input. The swing motor and transformer will run cooler and quieter.

RF_Burns wrote on Tue, 09 May 2017 05:59

...You may be better to consider running the fridge off an inverter into its 120V input. The swing motor and transformer will run cooler and quieter.

It also possible an aftermarket inverter will be less drain on the battery than the built-in chopper inverter.

http://www.bdub.net/Refrigeration_in_the_GMC.pdf

That is interesting. On my coach the outlets are on a GFI breaker while the refrigerator is on a breaker by itself.
Well, so much for that idea.

Ken Burton wrote on Thu, 11 May 2017 14:07

That is interesting. On my coach the outlets are on a GFI breaker while the refrigerator is on a breaker by itself.
Well, so much for that idea.

As near as I can tell from the manuals, GM never hooked up the 120VAC fridge power on the early models. When I took the OEM fridge out of the Sequoia "donor" to put in mine, I never found a cord. There was a two-spade connector on the "chattering protector" for AC connector, but no cable/connector from there.

I have a bigger Norcold that came out of a Palm Beach that had a regular power cord from the connector on the "chattering protector". So I bought/assembeld the stuff to make a cord/connector and made one identical to the Palm Beach fridge for the Sequoia. I used 120VAC to test it for functionality. I have never tried it on 12VDC.

And if your eyes haven't glazed over yet, I think I know the reason that GM never hooked up the 120VAC to the fridge.
A. The Onan can run slow or fast and the frequency will be outside what the swing-motor compressor will tolerate, and it won't last.
B. There is no reason to use the 120VAC input. Underway, its power originates from the engine alternator, through the isolator, the converter, to the fridge. "Dry" camping, it gets its power from the battery like it has to. On shore power or Onan, it gets power from the converter.

To summarize: There is never any need for it to run on anything but 12VDC, and the generator can kill it graveyard dead on its 120VAC if it runs too fast or too slow.

If I was going to keep it and use it, I would gut the electronics to eliminate the OEM "chopper" (square wave) inverter and install a 12VDC-to-120VAC 60Hz pure sine wave inverter connected to a 5:1 transformer to get the 24vac that the compressor wants.

Well, Here is another set data points....
My 73 23 (S/N 1650) did have a line cord and a plug.
The reefer was not on its own circuit, but that is not what killed it.
The only GFI are those I added.

There is a reason to keep the 120V power available. It just may not be worth the risk. If you have a coach that has the house bank in the front and you are trying to recover it with the buzz box powered from the APU, the line loss though the 25' of #10SAE wire (note - NOT AWG) is enough to make this operation problematic - As in the best charge rate you can get is about 25Amp.

That is my final answer and I don't need to call a friend.

Matt - Just greased his Lenzi hubs for the first time

Matt Colie wrote on Thu, 11 May 2017 18:09

Well, Here is another set data points....
My 73 23 (S/N 1650) did have a line cord and a plug.
The reefer was not on its own circuit, but that is not what killed it.
The only GFI are those I added.

There is a reason to keep the 120V power available. It just may not be worth the risk. If you have a coach that has the house bank in the front and you are trying to recover it with the buzz box powered from the APU, the line loss though the 25' of #10SAE wire (note - NOT AWG) is enough to make this operation problematic - As in the best charge rate you can get is about 25Amp.

That is my final answer and I don't need to call a friend.

Matt - Just greased his Lenzi hubs for the first time

If I needed all the amps from the charger to rejuvenate the house bank, and the 5A to the fridge was going to make or break the victory, I would turn off the fridge (in the case that I didn't have a way to run it off 120VAC). The fridge isn't that big, and there isn't that much food in it. But you shouldn't have to do that. Of the two ways I have suggested to increase the efficiency of the fridge, either method can re-use the existing voltage selector relay to retain dual voltage capability.

Aham,
What I am suggesting is that GMT&B original design was flawed. This is why they added (cobbled) the outside venting of the reefer for hot climates (but neglected to order the closing off of the original internal venting allowing communication between). They undoubtedly got both complaints about the charge rate and the warranty for the reefer being killed by the swing motor failure before the started installing absorption units. There were undoubtedly a few engineers hustling to get this all in a row. In real terms, the development time for the coach part was very short and did not allow for serious validation. - Says the guy who did vehicle validation. - This is not the first time and sure was not the last. I can provide many other anecdotal examples if you provide the beer.

But, after my own personal development, the only way to get serious on a decent house bank (more than a single Gp.29) is to relocate the converter. The possibility of successfully installing the required copper has a very low probability.

Matt

... It was the smaller of the 2 connectors under the refrigerator, behind the grill. ...BTW, do you prefer I use another name other than A. Hamilto?...