A.C. power draw

Andy mcd · 08-29-2018, 03:09 PM

Can both roof top a.c. units 13,500 truair max comfort units be ran at same time on 30 amp service

SarahW · 08-29-2018, 04:04 PM

You should be able to operate them both. Do you know how many amps they draw? What model is your RV and does it have a power control system? If equipped with electrical management, it will "shed" one A/C if the load is too high.

jerichorick · 08-29-2018, 07:47 PM

Quote:

Originally Posted by Andy mcd

Can both roof top a.c. units 13,500 truair max comfort units be ran at same time on 30 amp service

Welcome to the forum.
We could use a bit more info. What is your RV type, model and year?
Generally speaking yes but... You are pushing the limits. If the water heater kicks in you may trip a breaker unless you have an advanced energy management system built into the RV. Then you can switch to propane for the water heater. But, then, if you want coffee you may have to shut off a A/C unit. I can tell you more if I know more about your rig.
Rick

jhedges · 08-30-2018, 03:11 AM

My experience was the same. I could run two A/C's however, the water heater would kick on. I was trying to figure out why my amps were high, and at one point I shut off bot A/C's and the panel was still showing 13 or so amps. I was wondering what was causing this, then it dawned on my it was my WH. I was surprised the WH was causing that much drain on amps.

jerichorick · 08-31-2018, 08:37 AM

Quote:

Originally Posted by jhedges

My experience was the same. I could run two A/C's however, the water heater would kick on. I was trying to figure out why my amps were high, and at one point I shut off bot A/C's and the panel was still showing 13 or so amps. I was wondering what was causing this, then it dawned on my it was my WH. I was surprised the WH was causing that much drain on amps.

I see 11A for the water heater. I wonder why yours is 13A? What brand and size is your water heater?

In my last coach we had a potentially major issue with the water heater. The connections at the heater rod came loose. This melted the isolation plastic around the rod terminals. We smelt it burning. Took a while to figure out the source. Don't recall if I saw a difference on the meter.

al1florida · 09-07-2018, 06:18 AM

Quote:

Originally Posted by Andy mcd

Can both roof top a.c. units 13,500 truair max comfort units be ran at same time on 30 amp service

Yes, BUT. You want to be sure no other 120V loads are turned on. As already mentioned, the water heater. Also don't use the microwave, hair dryer, toaster, coffee maker, etc. What you can do is turn the thermostat temperature up so the A/C compressor shuts off on one of the A/C's and then use the other 120V device.

Also if for what ever reason your house batteries have been discharged pretty low, 50% comes to mind, the converter or charger will pull from 6-12 amps of 120V power while charging the battereis. That could be enough to trip the shore power c/b with both A/C's on.

**creativepart** · 09-07-2018, 08:58 AM

My Adventurer has the power control center built in to distribute power based on what’s available. I have a 30-amp RV plug at home (SouthTexas). When the RV is here and we first plug in to 30-amp the PCC will only run run one A/C unit at a time, but it does run them both just not at the same time. After the RV cools down over night, and the fridge is cold, and the batteries are fully charged the PCC will occasionally run both at the same time.

My PCC says the two A/C’s need 27 to 28 amps to start both compressors. So, 30-amp should do it. But even the smallest other load will make that difficult.

I notice there are plenty of times when one A/C is running with the compressor and the other is running with just a fan or that both are running on compressor but just not starting at the same time.