Community Forums

Stan&Jacquie · 03-04-2013, 08:43 PM

I know the refrigerator will run on AC when either on shore power or genset. My question is why won't it run on inverter when not hooked to shore power or running the genset?

Is this possible or isn't it setup to do this? I was thinking that with suitable solar to charge the batteries, the frig should be able to get enough AC from the batteries through the inverter to operate when boondocking.

Any thoughts?

Gorlininc · 03-04-2013, 08:51 PM

Did you turn the inverter on? There's a switch on the inverter and one inside the rig. Also make sure the circuit breakers are on in the inverter.
If the inverter is on, do you have power on some of your 120v outlets?
You should have power on the outlets, microwave and frige.
Also make sure you have good voltage on your house batteries.
What kind of rig do you have.
Rick

Stan&Jacquie · 03-04-2013, 08:57 PM

Quote:

Originally Posted by Gorlininc

Did you turn the inverter on? There's a switch on the inverter and one inside the rig. Also make sure the circuit breakers are on in the inverter.
If the inverter is on, do you have power on some of your 120v outlets?
You should have power on the outlets, microwave and frige.
Also make sure you have good voltage on your house batteries.
What kind of rig do you have.
Rick

Rick: My rig is an '07 Knight DFT 40'. The inverter button is engaged on the EMS and the microwave has power also but the frig electrical panel says "no AC". Rick:

docj · 03-04-2013, 09:04 PM

I assume you have an RV fridge. If that is the case many MH's are set up so the fridge cannot run off the inverter because the load would be too much. When not connected to shore power the assumption is you will run your fridge off propane.

crah · 03-04-2013, 09:15 PM

Stant

It seems some changes were made from some of the earlier years. For my year coach, I have two electrical outlets in the exterior refrigerator compartment. 1 outlet is hooked through the inverter and the other outlet is not. The factory default for my Monaco made coach for 2003 is that the refrigerator is plugged into the non inverter outlet and the Norcold ice maker is plugged into the inverter powered outlet.

I can just reverse the two if I wanted to run my refrigerator in electric mode through the inverter-I never have because the refer draws too much power. The Norcold in electric mode is not power efficient and draws too many amps. Unlike a house refer that cycles a compressor, the Norcold turns on a heating element to boil the ammonia (just like propane mode) but with a heating element instead of a flame.

Gorlininc · 03-04-2013, 09:27 PM

I also have 2 outlets for my Norcold.

My Norcold has always run off the inverter while I'm traveling. You are right. It draws about 8 amps at 120v. It's is the way I bought the MH and never thought about it.
I've put 12k miles on with the inverter on and refrig on. Never had a problem. You got me thinking about using the LP while driving. I'll have to do some more research.
Thanks for the suggestion
Rick.

Pusherpilot · 03-04-2013, 10:46 PM

Our 04 Imperial had a Norcold 1200. There were two outlets that powered it, one for the fridge that was powered from the shore power or generator only and one that was powered by the inverter. The thing ran off propane while off shore power but powered the icemaker all the time so you had the icemaker available no matter what power you were using, shore, generator, or inverter. The Norcold also has an auto mode that looks for an available cooling mode when it is turned on or it's power source changes, it changed fron shore power to propane automatically when I unplugged from shore power. I now have a Samsung RF 197 that draws far less power than the old 1200 and I run it on the inverter outlet all the time.
Ron

Mr_D · 03-04-2013, 11:13 PM

Quote:

Originally Posted by docj

I assume you have an RV fridge. If that is the case many MH's are set up so the fridge cannot run off the inverter because the load would be too much. When not connected to shore power the assumption is you will run your fridge off propane.

Exactly what ours does, unplug the shore power and the refer automatically switches to gas. Running the generator will allow it to run on electricity also.
We had CW install a 2,500 watt inverter in our 2000 DSDP in place of the original 400 watt one. Since they didn't split the circuits (like I thought they would and should have for the amount they charged) I could run the refer and even the heat pumps off the inverter/batteries. I had to remember to switch the refer manually.

K7JV · 03-05-2013, 07:39 AM

Good information from all, on this one. One thing to note when putting loads on inverters, is that the current draw on the coach batteries is approximately 10 times what it is on 120VAC. That is because of the voltage ration of 12 volts to 120 volts. On purely resistive loads, the kVA demand is the same as the watts demand. On motors, or other reactive loads, the ratio goes up due to the reactive load VARs. So on things like heat pumps, A/C's, motor driven tools, the factor can be considerably higher than 10 to 1. So just remember, when you put an 8 amp load on your inverter, you are putting at least an 80 amp load on your battery. That's a lot!

Also know that a 200 amp-hour battery bank can't begin to deliver that many amp-hours, if the current draw rate is high.

Inverters, when off of shore power or generator power, can take batteries down in a real hurry. They're still an awesome addition to our RV's. We just need to know not to expect them to replace the energy capabilities of shore power connections or on-board generators.

Stan&Jacquie · 03-05-2013, 02:52 PM

I'm sure learning alot from this. My assumption is that RV refers are meant to run on propane when boon docking and not off of the inverter if the genset is not running. If the electrical load of 8 amps on the EMS is actually a load of 80amps at the battery then even solar charging is not sufficient to make up the draw.

OK then....if I want to go electric, I should go with a residential refer. Otherwise, I should be content to go with propane when boon docking (unless I am willing to run the he set).

Thanks again to all for your assistance. If I haven't got this right please correct me.

information from all, on this one. One thing to note when putting loads on inverters, is that the current draw on the coach batteries is approximately 10 times what it is on 120VAC. That is because of the voltage ration of 12 volts to 120 volts. On purely resistive loads, the kVA demand is the same as the watts demand. On motors, or other reactive loads, the ratio goes up due to the reactive load VARs. So on things like heat pumps, A/C's, motor driven tools, the factor can be considerably higher than 10 to 1. So just remember, when you put an 8 amp load on your inverter, you are putting at least an 80 amp load on your battery. That's a lot!

Also know that a 200 amp-hour battery bank can't begin to deliver that many amp-hours, if the current draw rate is high.

Inverters, when off of shore power or generator power, can take batteries down in a real hurry. They're still an awesome addition to our RV's. We just need to know not to expect them to replace the energy capabilities of shore power connections or on-board generators.[/QUOTE]

Gorlininc · 03-05-2013, 02:59 PM

Hi Stant

If say your math and reasoning is correct. However when I'm running the alternator on the highway. It can handle the 80 amps but I agree the load is great. For now on I'll put it on LP.
Thanks
Rick

doublechevy · 03-05-2013, 04:41 PM

On my o8 Knight the 120 volt for the refrig is not connected to the inverter but the 120V for the ice maker is so you can make ice cubes when running on gas. there are two outlets in the outside access compartments one is on the inverter for the ice maker the other is for the refrigerator when connected to shore power or running the generator.

K7JV · 03-06-2013, 05:29 AM

'Fridge on shore power and ice maker on the inverter makes good sense. The ice maker demand lasts only a minute or so, while the ice dumps and re-fills with water. That's easy for the inverter. The inverters are good for short term, medium-demand jobs (toaster, coffee pot, hair dryer), and longer term, low-demand jobs (TV, computer).

Also, there's a lot of talk about having propane on or off, or generators on or off, while on the road. Twenty RV'ers will give you twenty different answers, too. As for us, we only turn off our propane when re-filling the propane tank. Since we're diesel, and always fueling a long way from the risk of gasoline fumes, we normally don't turn it off when refueling the coach. I should add that the kitchen burners and the 'fridge are the only propane use points on the coach, as we have an Aquahot. We also routinely run the generator on the road, if we need the air conditioning help from the roof units.

bruceisla · 03-06-2013, 05:54 AM

We have a residential reefer and no 120vac power leg from the inverter ... while on the road the reefer stays safely cold (without power) for about 6 hours if we keep the doors closed. Not an issue for us. If necessary, we can run the genset.