Escapees March-April 2023

mark, my words

Your RV Questions By MARK NEMETH #45776, Escapees Technical Advisor Send your questions via e-mail to techquestions@escapees.com

Charging System Q. I live in Taos, New Mexico, and have a problem with the charging system in my Ford 350 Econo Van Camper Conversion. I have three ways to charge the “house” batteries: 1) 110-volt shore power, 2) solar panel on roof, 3) diesel engine. Methods 1 & 2 work fi ne, but the engine does not seem to be charging the house batteries now. A couple of years ago, the problem surfaced and I solved it by buying two new engine batteries. Seems they were old, and it was all the charging system could do to charge them with nothing left over for the two house batteries. But, these batteries are still in good shape, so the problem lies elsewhere. Any thoughts appreciated. Terry A. Most RVs utilize either a diode block battery isolator or a solenoid switch to isolate the engine-starting batteries from the house batteries. The way this is supposed to work is the isolator allows charge current from the vehicle’s alternator to charge the house batteries but prevents the house battery circuit from drawing power from the starting batteries when the engine is off and the RV is parked. The diode-style unit is usually a small metal box with three terminals on it. The center terminal is connected to the alternator output, and the other terminals are connected to the positive post of 1) the starter battery and, 2) the house batteries. You’ll usually fi nd it in the engine compartment close to the alternator. The internal diodes only allow current to fl ow “to” the batter ies, and will block current from fl owing “out of” the batteries. The relay, or solenoid, style can be mounted just about anywhere. It essentially

Outlet Diagram Correction In the Mark, My Words column in the November/December 2022 Escapees Magazine, you included a diagram showing RV Power Outlets. The RV 50A outlet (NEMA14-50R) should have also showed 208V in addition to 240V across the two hot legs as a possible voltage. Some RV parks have commercial 3 phase 208Y/120 volt transformers serving the park's pedestals. These trans formers still provide 120 volt circuits to the pedestals but you will read 208 volts across the two hot legs at the pedestal rather than 240. Bob Rohrmann # 111598 Right you are, Bob! Here’s an updated outlet diagram. Mark Nemeth

ties the positive posts of the starter battery and the house batteries together whenever the ignition switch is on. This effectively parallels the two batteries for charging. Once you determine which setup you have, it’s fairly easy to test with a meter. There may also be a fuse or circuit breaker in the charge circuit, and the problem may be as simple as a blown fuse or failed breaker. This website has some good, basic wiring diagrams of the different types of isolators: www. custombatterycables.com/battery_isolators.htm Winterizing Water Pump Q. I bought a new Komfort 2027RL travel trailer, and I can’t seem to fi nd where the water pump is located for the purpose of winterizing the trailer. Do you have any suggestions? Nian A. If you have an owner’s manual for the trailer, it may show the pump location. Calling a dealer may also help you fi nd it, but I have an easier solution: The pump will normally be located in a compartment or cabinet where it can be accessed fairly easily. My advice is to turn the pump on and fi nd it by ear. They make a fair amount of noise when operating, so you should be able to locate it. Good luck in your search.

RV Power Outlets

120V

120V

120V

0V

GND

GND

208–240V

0V

120V

HOT

HOT

120V

120V

Neutral

NEMA TT-30R | 30A | 125V

NEMA 14-50R | 50A | 250V

120V

0V

0V

120V

GND

GND

120V

120V

HOT

Neutral

HOT

Neutral

NEMA 5-15R | 15A | 125V

NEMA 5-20R | 20A | 125V

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ESCAPEES Magazine March/April 2023