best way to run residential fridge on limited shore power?

[brandonrv]

So my new coach is 50amp and I am going to a camp this weekend that just has 30.

I'm just trying to conserve as much amps as possible to avoid a brown out. Ill have to have both ACs on while we are in the coach at full blast due to it being really hot out.

Are these residential fridges an LP hog?

It's a norcold 4 door. I was told the battery will run it which leads me to believe the LP would be fine as well.

With both ACs on high cool it leaves me with about 10 amps to work with. I'll run the water heater on LP for sure.

Just wondering what others do. If it burns too much LP it's probably worth just running it on the 30amp power. I'll just have to watch what else we plug in with 2 ACs, Fridge and the TV goin.

Thanks

[valhalla360]

smkettner wrote:

brandonrv wrote:
At what point is it damaging the AC? below 100V or is that 106 - 109 an issue?

Motor is rated 115v +- 10% so 103.5 is the lowest but that is right at the motor. I would consider shutting one down if you are dipping to 105.

Consider a powermaster booster if you will be doing this frequently.

Of course, in reality it's not a hard and fast number.

Run if for a weekend at 105V and you will probably never "see" an issue to it. Do it regualarly and instead of a 15-20yr life, you may only get 5-8yrs out of the AC units.

Of course, I'm talking in gereraltites. Predicting the exact life based on your usage is near impossilbe. The point being, unless the voltage goes way low, it isn't likely that the AC will run for an hour and then the compressor dies suddenly. It's more of an accumulation of damage.

I don't like when the voltage gets much below 107-108V.

A suggestion: If you don't use the sleeping areas during the day, do you really need them cooled? We only have a single AC but when it gets into the 90's and above, we often close off the sleeping area and just cool the main living area during the day. At night, with the sun down, you need far less cooling, so we open the ducts to cool the sleeping area.

[Bill_Satellite]

You might want to read the responses. He does not have a residential fridge.

[AllegroD]

I have not read all responses.

An RR does not use LP. It is elec only. The issue is start surges of the three items, 2 AC and 1 RR. What are the surge amps at start up. There is a potential that if you do not have an EMS that 2 AC starting at the same time will pop the CB. if both AC are running and drawing 13 amps each, total 26, and the fridge compressor starts, you might pop the CB.

[Executive45]

A side note to the OP...make sure your Norcold is not involved in the recall...if it is, make sure it's been done....Dennis

[Desert_Captain]

To run both AC's on 30 amps(and you will have something less than that), you will need to turn everything else off. You also ned to have EMS protection or at the very least a voltage meter and then watch it like a hawk. When you are operating right on the edge all it takes is a few neighbors turning things on and your voltage will drop to dangerously low levels. Everything may keep running but you are taking years off of the life of your AC units.

When it gets 105 here in Tucson and that happens a lot in summer we either go up to 7, 8 or even 9,000' to beat the heat. If we can't do that we stay home. Camping in anything over 100 degrees just does not sound like anything I want to do.

As always.... Opinions and YMMV.

:C

[time2roll]

brandonrv wrote:
At what point is it damaging the AC? below 100V or is that 106 - 109 an issue?

Motor is rated 115v +- 10% so 103.5 is the lowest but that is right at the motor. I would consider shutting one down if you are dipping to 105.

Consider a powermaster booster if you will be doing this frequently.

[DanTheRVMan]

I have successfully run two ACs occasionally on 30 amp. I would never leave the MH like that as the breaker could kick and the dog would suffer.

Expect the breaker to trip. Typically at a bad time even with almost everything turned off.

Some locations I can not even get 2 ACs working at all.

water heater, and norcold need to be on propane. Battery charger as low as possible or off during the day and charge the batteries on a low setting when possible.

I do not like 30 amp in spring or fall, but hate it during the summer.

[brandonrv]

OK i was wrong it's pulling the line voltage down to 109ish. Saw the 2nd zone go to 106 for a brief moment.

Total amps it's using hover between 18-20. These are airexcel high efficiency ACs if that matters. I put them on cool high. Don't think it registers fast enough to show the spike when it kicked on.

Only reason I need the 2nd one on is to get enough air into the back bedroom for sleeping at which point I would have everything else off.

At what point is it damaging the AC? below 100V or is that 106 - 109 an issue?

[hanko]

Residential frig a LP hog???? trying to figure this one out.

[valhalla360]

brandonrv wrote:

valhalla360 wrote:
Propane for the fridge should be fine but you will be pushing that 30amp outlet to run 2 AC units.

Keep in mind a 30amp outlet is actually only rated for around 25amps. You might want to check the voltage drop to make sure you aren't killing your AC units with low voltage.

What do you mean by check voltage drop? Just make sure the voltage is not dropping below some threshold?

If you push up near the limits, the line voltage doesn't always keep up (especially in a campground with lots of RV's all running thier AC). If the voltage drops a little, it's not a big deal. If it's down to 100volts or less, there can be problems.

2 AC units is really pushing the limits. Keep in mind:
- Your battery charger will kick on occassionally drawing a few amps.
- TV, laptop, phone chargers can add a couple amps.
- When one of the AC units starts up, it will draw far more than the rated amps. Since you are already using close to your max, the odds of tripping the circuit go up significantly.

If you do try this make sure to check the plug periodically to make sure it isn't overheating.

[brandonrv]

John S. wrote:
But what is the load drawing the AC voltage down too? I do not run two acs on a 30 even when I had a LP fridge. It will eventually trip the breaker. My AC units use 14 amps each and more at startup. Unless you have a EMS to guard against low power you need to look carefully at your laid there. There is a battery charger and converter running too.

Has a voltage monitor for L1 and L2. They are hovering around 118-120ish

[John_S_]

But what is the load drawing the AC voltage down too? I do not run two acs on a 30 even when I had a LP fridge. It will eventually trip the breaker. My AC units use 14 amps each and more at startup. Unless you have a EMS to guard against low power you need to look carefully at your laid there. There is a battery charger and converter running too.

[brandonrv]

bluwtr49 wrote:
The refrigerator will be the least of you worries on 30A. It's unlikely you can run both AC units at all much less both units and anything else AC like microwave, hot water heater, TV, and etc.

A brown out isn't much of a concern but expect to trip the breaker periodically.

Both ACs are using 19 amps at full blast.

So yeah doesn't give me much room for anything else. We'll have to juggle it.

[2oldman]

brandonrv wrote:
Yeah I was worried about "residential refrigerator"..

Maybe they forgot the word 'size'.