Wiring an inverter in an RV
Installing an inverter without a standby battery charger function can be simple, if it is acceptable to simply plug a few appliances into the inverter as needed. The inverter connects to the battery and produces AC power at its own outlet, or to an outlet added to the RV for this purpose.
A more convenient and advanced installation would use the standby inverter which contains a battery charger and transfer switch. The standby inverter is permanently wired in to the RV so that power from the inverter flows directly to most appliances, lights and outlets through the existing RV AC wiring circuits. The STANDBY inverter also charges the batteries when either generator or shore power is connected, and also switches that outside power through to the RV AC wiring.
DETAILS OF INSTALLATION: The standby inverter is connected between outside sources of power and the RV AC breaker box. Any outside power from generator or shore power hookup goes to the standby inverter, and there is switched through to the RV AC wiring. Outside power is also used by the standby inverter to recharge the batteries. When outside power is disconnected, the inverter senses this, stops charging the batteries, and begins to convert battery power into AC power which it sends to the RV AC wiring.
To do this installation, the shore power/generator cord must be disconnected from the original AC breaker box and connected to a second, smaller AC breaker box installed in the RV next to the original one. This new breaker box will carry only outside power that comes in on that hookup cord: generator and shore power. The new breaker box contains at least one circuit breaker, which passes the outside power to the inverter's AC IN terminals.
One or more additional breakers in the new outside power breaker box may be used for a few appliances in the RV that can not be run on battery based power, because they would quickly deplete the batteries. This might be the air conditioner, and any electric heaters or electric water heaters. These few items must have their circuits moved from the original breaker box and into the smaller second breaker box that carries only generator and shore power. Also the original converter, a type of battery charger built into an RV, must be disconnected from its regular AC source circuit in the main breaker box, and connected to the second smaller breaker box, so the inverter/battery AC source will not operate the converter.
The standby inverter AC output terminals are the power source that gets connected to the original breaker box, at the point the shore power cord was removed. When generator or outside power is connected to the shore power cord, it enters the new breaker box, passes to the inverter's input terminals. The inverter automatically passes this power through to the RV main AC breaker box and thereby to all the lights and appliances. When outside power is disconnected, the inverter begins to produce AC power from the batteries, and now switches its own AC power to the RV main breaker box and thereby to all the lights and appliances.
An inverter must be located within short wiring distance of the batteries, about 10 feet cable maximum to connect it to the battery. A simple AC wire brings outside AC power from the new breaker box to the inverter, and another takes inverter AC power back to the original RV breaker box. This way the inverter can be installed in a protected clean ventilated location near the batteries and easily wired to both breaker boxes.