Community Forums

Unplanned Tourist · 06-16-2017, 06:37 AM

I always keep one of these in the rig- https://www.amazon.ca/gp/product/B01...?ie=UTF8&psc=1
It will tell me the voltage on one branch anytime. I keep it plugged into an outlet on the kitchen counter. I can also use it to measure amperage going to the MH if I plug into a 15 amp outlet. Get one of these and watch the voltage to see if it's changing, and if it goes down, unhook the charge line to the batteries. This will tell you if the charger is kicking in and causing your problem.
Good Luck.

okcnewbie · 06-16-2017, 08:14 AM

Quote:

Originally Posted by Unplanned

. ....Get one of these and watch the voltage to see if it's changing, and if it goes down, ........

I think you meant current?

JumboJet · 06-16-2017, 08:44 AM

If this is going to be a long term requirement, have an electrician install you a 50 AMP service.

I have a 2003 Expedition and I have noticed the variations in the AMP load and mainly attribute it to the Inverter/Battery charger.

Scottybdivin · 06-16-2017, 09:15 AM

If you have the option of running your 50A cord all the way to the receptacle and adapt there, it will reduce the amount of line loss. I've had to learn this lesson the hard way

GearGirl · 06-16-2017, 10:18 AM

For those suggesting running 50A to RV outlet at house, I had considered that already but I would need about 70 feet of 50A extension cord to do that. That's the closest I can get to the panel. I'm selling the house, sounds like a lot of expense for short term.

GearGirl · 06-16-2017, 10:21 AM

For those saying it's because my batts are charging, why would they only charge when I turn the portable AC on? I don't get these fluctuations/steady increase any other time, but the RV stays plugged in 24/7 (I normally run small fans in the RV to keep air circulated, only 1-2 amps ever register even with a few lights on).

GearGirl · 06-16-2017, 10:24 AM

I wish it stretched that far :( the outlet I'm plugged into IS closer than if I create an RV outlet at the breaker panels and try to plug in there, but I still need an extension cord.

Mudfrog · 06-16-2017, 10:56 AM

Again, not an expert but wouldn't an air conditioner draw more amperage when temperature rises and head pressure goes up? That would account for why the amperage goes up gradually.

I believe GearGirl stated in her opening post, that temps were getting over 100. That little AC unit is going to be working hard in those temps.

Dupdyke · 06-16-2017, 11:43 AM

Plug ac direct into extension cord see if it works later plug rv in and let charger bring it back up to normal

Unplanned Tourist · 06-16-2017, 12:19 PM

Quote:

Originally Posted by okcnewbie

I think you meant current?

No, I meant voltage. If voltage is dropping, that's a bad thing. Too much load for the wire size.

DrDaveMA · 06-16-2017, 02:26 PM

A couple of observations, you stated you are moving shortly, in my opinion that says use an extension cord, it will always be usable. Just be sure it is rated for 50 amps, at 75 feet you are going to need 6 gauge wire (assumes at least 25 feet of coach cable giving you a total length from the plug/power box, in excess of 100').

mrt_1111 · 06-16-2017, 03:57 PM

Power = voltage x current. So if voltage goes down, current must go up to compensate. Extension cord or plugs may not be up to the task.

twinboat · 06-16-2017, 04:01 PM

Quote:

Originally Posted by mrt_1111

Power = voltage x current. So if voltage goes down, current must go up to compensate. Extension cord or plugs may not be up to the task.

Not if there is resistance in the wire. The amps are spent creating heat. You get less of both.

nothermark · 06-16-2017, 04:31 PM

There is always resistance in the wire. I would be monitoring the voltage at the RV end or in a socket in the RV. If the line voltage is dropping then check the voltage at the other end of the cord and make sure the problem is not the house supply.

I don't feel like running the numbers but there should not be much drop on #12 wire with 12-15 Amps. It should not be generating enough heat to change resistance significantly after a few minutes of stabilization. If there is heating it will be at the plugs so give them a feel and see if they are getting hot.

As the temperature rises the A/C is working harder to cool the interior. I would expect to see that as cycling *unless* I had a high efficiency unit with a constantly running variable speed compressor. If that is what you have then what you describe is proper operation. RTFM on the A/C model.

I'd be inclined to get one extension cord for the RV as you will likely need it some time. That would let you use a shorter cord between the big cord and the outlet. That would reduce the line drop.