Chinook RV

Also, if you can see the label, just about every AC appliance tells how many watts it uses. Watts are universal: To see how many amps that means you divide by the voltage. So for example:

Given appliance uses 700 watts

If you run it on AC, that's 120 volts (roughly). 700 divided by 120 is 5.83 So the appliance is using 5.83 amps on AC power.

Now take the same 700 watt appliance and run it on DC. Now you have to divide 700 by 12 (because it's 12 volts). 700 divided by 12 is 58.3 So to run the same appliance on DC power takes 58 amps

This tells you why running certain "household" appliances on DC is difficult. That's not your question here though, I realize. Mostly I just wanted to mention that many appliances will list the watts they take to run on the label. Once you know that you can divide by whatever your voltage is and see how many amps it will take.

I think I have a photo of the label from my Concourse's original roof AC. If I can find it and it lists the watts I'll add that here.

BG

PS: Well of course the photos of the label on the airbox are crystal clear but they don't list wattage. The label on the Air-con was too blurry.

But I looked it up online. A quick search shows that a Duo-Therm 13,500 btu unit (my Chinook original was 16,000 btu, so even larger) takes 3,000 watts. On AC power that's around 25 amps. A 16,000 btu would be more, so that tells why it won't do well on a 15 amp breaker/cord... (That said, the original Chinook Air-con breaker was 20 amps, so the larger draw must be a surge that isn't long enough to trip a 20 amp breaker; still, 15 amps seems too small, especially cause you might simultaneously use other things that take electricity.

Kill-a-watt is handy at times, but the one that most of us have only good for 15A, and it may blow a fuse inside the device if you try to pull more than that. I would not try to put the kill-a-watt on the cord if I am going to turn on the AC. There are ammeter or DMM for that.

chin_k wrote: August 1st, 2018, 7:33 am Kill-a-watt is handy at times, but the one that most of us have only good for 15A, and it may blow a fuse inside the device if you try to pull more than that. I would not try to put the kill-a-watt on the cord if I am going to turn on the AC. There are ammeter or DMM for that.

What does your air con draw?

I suggested the Kill-a-watt because they are foolproof, safe, and cheap. Mine has an over-current alarm, and a resetting fuse, and at $19, I'll test anything.

If someone doesn't already have a meter, or the inclination to get one, they might get confused buy a description of the task, so I skipped that.

I think this is the thread that Kirah was warned about using the 15A cord. I found a dedicated 20A circuit that I can test right next to the rig, so I am going to to try to turn the AC on and see how much it draws. Before, there is a 10A resettable fuse on the extension cord that I use so I was never able to run the AC at all. As mentioned, it is the initial rush of the capacitor that draw a big rush of current. I am not getting the soft-start capacitor, and the kill-a-watt do not have the max power feature, so it will just be the power to keep the AC going. I probably will do this over the weekend, however. Firemen is less busy on weekend

I plug the rig in the Kill-a-Watt, and this is what I see.

1, with nothing on the main breaker, 0 Watt
2, inverter on, 20-25W
3, fan on, low 380-385W
4, fan on, hi 425-430W
5, AC on, fan low 1140-1380W

I only look at the meter for a few minutes. When the AC just started, it was on the 1150W side, but when I got bored after a few minutes, it was higher at 1370 watts or so.

It is less than 15A, but I just don't feel comfortable leaving it on without supervision. I did the test above on a 20A circuit.

Thanks for the update. Yes, this was the thread I was thinking about when considering whether to use my A/C while parked in my storage area.