Is there an Electrician in the house?

kfrimr · August 4, 2017

We are dry camping this summer in a beautiful place. 20 miles from Mt Rainier with a stunning dining window view. With only a 15 amp of electricity. Recently something happened, not sure what. I have a Maginum Hybred inverter, and a Power Control System by Precision Circuits Inc. When I have no load it shows 120V but as soon as I put any kind of load it drops to >100 and turns off. For example when I turn on the water heater at 11Amps it drops voltage to 99 and kicks the PCS to disconnect the power. Is this a sign that my PCS is going out or is out? Or some other electrical issue? Any Ideas?

Kent

Stan Wright · August 4, 2017

Loose or dirty connection?

Chad Heiser · August 4, 2017

There are a couple of things you need to do. First you need to set the incoming power level for your Magnum charger. I would change it to 10 amps or maybe 7 amps, depending on how much charging you want the Magnum to do to your batteries. It is probably set at 30 amps or maybe even 50 amps right now if you have never changed it before. The Magnum is very smart, but it has no way of knowing what power is available (what you are plugged into) unless you tell it ahead of time. I usually leave mine st to 30 amps so I don't have to mess with it when I move between 30 amp and 50 amp camp sites. The only time I actually change mine is when I am in a situation like you and I am plugged into something less than 30 amps.

The second thing I would do is turn the hybrid inverter on. It will stay in standby mode until it is needed. Plugging into a 15 amp power supply is one of the things the hybrid inverter is intended to help with. I don't know what all 120 volt appliances you have in your coach, but most of them are probably drawing a little power all the time (like TV's, dish boxes, residential refrigerator, microwave clock, etc.). These draws, along with the charger draw on the Magnum, combined with whatever else you are turning on are more than likely overwhelming the 15 amp circuit. This is causing the voltage drop and the subsequent activation of your EMS cutting the power due to low voltage. With the hybrid inverter turned on, it will supplement the 15 amp power source with inverted 120 volt power from your battery bank to supplement the power in the coach. It will take over powering 120 volt appliances on your sub panel and leave the full 15 amps from the shore power to power the appliances on your main panel. The inverter will also be smart enough to shut off its internal charger while it is supplemting power in hybrid mode.

You do need to be careful that you don't run in hybrid mode and supplement power too long because you could draw your batteries down. If you pay attention to the Magnum remote, it will let you know where you are at on state of charge. If you get too low, start shutting things down and allow the Magnum's charger to run for a while to bring the batteries back up to an acceptable level.

Edited August 4, 2017 by Chad Heiser

RandyA · August 4, 2017

X2 on Chad's reply. But, I have one question/addition. What is the length and gauge of wire you are running from the power outlet? If you are using a conventional outdoor extension cord that is 16 or even 14 AWG and have more than 25' of cord the resistance of the conductors at or near a 15 amp load can be significant. Again, speculating...... the 15 amp outlet at your campsite may have been wired with the requisite 14 AWG cable for 15 amps. If the park's cable to the power pedestal is one of those 100 foot or more runs again the loss of power to resistance in the cable as amperage draw rises can be significant. One way you can check this is to plug a 1200 watt hair dryer or small 1500 watt electric heater into the 15 amp campground outlet and observe the voltage drop at their plug with a volt meter. This simple test would tell you if the voltage drop problem is yours or the campgrounds. You need at least 12 AWG cord running to your camper or to your 50-50 amp camper cord and bridge-adapter. There is nothing you can do about the voltage drop if the park is wired with smaller gauge cable.

Even if this is not the problem, or even if it is, I think Chad hit the nail on the head when he suggested using what power you had available to charge your batteries on a 24 hr basis of need and then use the inverter to pull current from the batteries at whatever intermittent level you need.

Sounds like a beautiful place. I think I could suffer through 15 amps in one like that provided it wasn't 100 degrees .

HERO Maker · August 4, 2017

What they both said! The only thing I would add is to check those items that you really don't need to be on. Like the hot water heater. Switch from electric to gas. Not using the microwave? Shut the breaker off.

I'm thinking when on a 15 amp plug, or even a 20 amp, you are really "camping" and you should think that way even in our rigs with all the fancy stuff. JMHO.

If you have a gen. system, well then you have more flexibility.

kfrimr · August 15, 2017

Thanks guys, Checked everything as was suggested, then found that I was plugged into an outlet that had 14g wire on a 15a breaker. Moved to an outlet that was 12g wire and 15a breaker and all is working.

So I have 1000W of Solar and 500Ah of Lithium batteries. With the Magnum Hybrid inverter and a 1500 Heat-pump/AC with a "Soft-Start" installed and I can run for most of the hottest part of the day. The Magnum gives about 20a of "Load Support". So gives me plenty of AC until sun down the AC off and still have sufficient to run Residential Refrigerator and evening lights.

Thanks for your helpfulness

Kent