Steve Savage submitted this article to RVtravel.com when he was a Master Certified RV Technician with Mobility RV Service.
We were camped and the Progressive Power Management system I had plugged into our camper killed the power to our fifth wheel. When I went outside to check the box, the system provided me a readable code that told me why: The voltage to our camper was too low. What does that mean and why is it important to have the right voltage? I’m glad you asked.
Why it’s important to have the right voltage to your RV
Everything in your camper that runs on electricity is designed to operate within a certain voltage range. Although it may vary by a few volts, depending on the appliance, generally speaking the range is about 105 volts on the low side to 130 volts on the high side. When the voltage coming into your RV is not within those limits, things start to get hot. When they get hot long enough, they go to heaven. If things go to heaven, you have to pay for new ones and have them installed.
If you think of the power supply in your campground like a water system — with water taking the place of electricity and pipes taking the place of wires — you can think of it this way. So much water is available to the campground from the utility company and coming into a main. From there it goes down the pipes to the pedestal at your campsite where you plug in. When the campground is not full, not many people need water, so there is no problem. You have all the water pressure (voltage) you need.
What about power supply when the campground is full?
If those pipes are not large enough to meet everyone’s need for water, there is a problem. The problem is low water pressure, or in the case of inadequate wiring, low voltage.
At our campsite, then, those wires were too small and our power management system was killing the power to protect the equipment in our camper. The voltage, varying greatly, was running between 118 volts and 105 volts in an unpredictable manner. I would guess it was pretty much in sync with compressors kicking off and on in our neighbors’ RVs. Should that happen? Absolutely not! It happens because the wiring system in the campground couldn’t carry enough electricity (current) to meet the needs of the equipment that depends on it.
Shouldn’t the circuit breakers have tripped?
So, if you get an idea of what is happening, shouldn’t the circuit breakers have tripped or my air conditioner shut off? Unfortunately not. Breakers respond well to rapid heat rises, but will allow everything to continue merrily on its way when voltage is running low. Although low voltage is not good for any equipment, it most commonly destroys the relays in the air conditioner which feed power to the compressor, as that compressor is a power pig, even when working at its best.
When relays get hot for prolonged periods of time, the contacts literally weld themselves together. If you or a friend has ever had an air conditioner that did not shut off after the fan had stopped running (you heard a continual hum unless you tripped the circuit breaker to the AC), that is most likely what has happened. If you have noticed the circuit breaker box (more correctly called the “power distribution panel”) has gotten hot or smelled like melting plastic, bingo, low voltage again. When I went outside our camper, the breakers and wires in my neighbor’s power pedestal smelled like they were melting. Same thing: low voltage.
What could I do to get the right voltage?
So what could I do to deal with the situation and get the right voltage for my RV? Not a whole lot. I guess I could have sneaked around and unplugged all my neighbors’ shore lines and killed their power so I had more. That would have likely brought me more grief than what I already had. There is no likelihood the campground is suddenly going to be updated (though I was told it is in the planning stages). Other than that, I stopped using my power management system and monitored the voltage with my multimeter. If my power dropped to 104 volts, I would have killed my air conditioner and made do with just the fan until temperatures and, hopefully, power usage dropped that night.
Of course, if I had known there was a power issue in this campground, I would not have reserved a site. It is a given we will not be back next year as, even at my wholesale rates, we still have to pay for parts like everyone else.
You need a power management system
In the event you are new to the issue of low voltage and its effect on an RV’s components, what should you do? The need for a power management system (not just a surge protector) is a given. If you don’t want to invest in that, buy one of the power monitors you plug into the receptacle on the wall of your RV and see what it reads around dinnertime, when power usage in campgrounds normally peaks. A monitor costs a great deal less than circuit boards or compressors.
A final thought about the dangers of low voltage has to do with the life of your companion animal. If you are using a power management system that shuts down the power to your rig in the event of low voltage (they all do), if you have a companion animal and left the air on to keep it cool, low voltage could create a life-or-death situation without sounding a warning. Just something to keep in mind, if you are concerned about whoever is in your RV when you are not there.
How common is low voltage?
In older campgrounds, low voltage is extremely common because they were often built before 45-foot motor homes and 40-foot fifth wheels became commonplace. If by chance you write a review of a campground and experience a problem with low voltage, be sure to note it in your review.
RV Electricity – Just Ask Mike (J.A.M.): How low of a voltage is too low?
Plug-in digital voltage tester on Amazon.