We often get calls from customers about why their refrigerator won’t turn on even though it’s got 120 Volts at the plug, so I feel like a quick explanation of the electronics and electricity required would benefit everyone.
There are three main systems in a standard ammonia refrigerator used by the RV and Boat industry. The control board system, the electric heating system, and the propane system. Each of these systems is powered differently. To fully operate the refrigerator in any mode all three systems must be in good working order. Each system and it’s primary criteria for correct operation are explained below.
Control Board System: This system consists of the front panel controls as well as the main control board located at the rear of the refrigerator. both of these boards must have a minimum of 10.5 volts DC supplied to them to operate. Anything less and they will not appear to function at all. More than 15 volts DC will also cause significant problems, so keep your battery and charger maintained.
Electric Heating System: This system consists of the electric heating elements and the 120 volts AC wiring and outlet. The standard heating elements are activated by supplying 120 volts AC to them. this is only accomplished if the Control Board System allows the 120 volts AC to flow through to the heating elements. So you can start to see why just having one source of power is not enough. This system may also consist of a 12 volt DC heating element on a three way refrigerator. This is less and less of a common option all the time, so unless you know that you have three way refrigerator don’t worry about it.
Propane System:This system consists of all the components that are required for a good quality propane flame to be present. These include the propane tank, hoses, solenoid, orifice, burn tube, shroud, and baffle/flue. Since this conversation is about the electrical portions being misunderstood we’ll cover the actual function of each of those components later. The lesson here is that for all those components to work properly you must have a filled propane tank with all shut off valves set to the open position and once again a good DC power source to the control board. Unless the Control Board System allows the solenoid to open, thereby allowing gas to flow, and then allow the striker to ignite the propane, the propane system will not work.
So in conclusion having only DC power, or only AC Power, or only Propane, does not supply you the necessary operating parameters for any current refrigerator on the market today. You must always have DC (Battery) power above 10.5 volts and one other power source, unless you have the rare three-way refrigerator which will continue to cool with only DC (Battery) power supplied.