How to Wire an RV Power Converter

by John Cagney Nash
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A recreational vehicle, or RV, uses a power converter to produce 12 volt direct current, or DC, from 120 volt alternating current, or AC. This 12-volt DC electricity is used in two ways. First, it directly powers 12 volt equipment directly from shore power or a generator, so the coach battery is not depleted. Second, it has an in-built battery charger that charges the coach battery from the AC mains. The chassis battery is not charged by the power converter, because it does not share wiring with that part of the 12-volt system. An RV power converter is a vital component in the vehicle's system, and wiring one is not a complex project.

Step 1

Disconnected your RV from shore power and/or switch off your generator. Loosen the clamp holding the ground cable to the coach battery and remove the cable.

Step 2

A power converter typically has four terminals. Consult the instructions provided with the device, and wire it accordingly. The four terminals will be printed or embossed with their function, and the usual lay-out of color-coded wires to terminals is to connect the coach battery feed terminal to a red or black wire; connect the coach battery negative terminal to a white wire; connect the shore power hot terminal to a blue or black wire; connect the shore power neutral terminal to a white wire.

Step 3

Trace those wires of identical colors to find out which serves each purpose. Typically the white wire to 120-volt shore power neutral will be of a larger gauge than the white wire to 12-volt ground.

Step 4

Reconnect the negative pole of the coach battery to its cable.

Step 5

Reconnect the shore power umbilical cord to its outlet.

Step 6

Test the power converter output using a voltage meter. Bridge its probes or alligator clips across the 12-volt DC terminals and check that the reading is approaching 14 volts.

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