The electrical boxes in RV parks, colloquially called hookups and properly called connection pedestals, are conventionally wired to supply 50-amp and 30-amp shore power cords. They may also have one or two 20-amp traditional household outlets for use by tent campers. All the outlets must be protected by watertight shrouds. Some pedestals, mostly in residential ownership parks, are equipped with meters, Internet and cable television connectors. Wiring an electrical box for an RV park is not of itself a complicated project, but the ramifications of making a mistake can be great.
Install a 50-amp circuit breaker in the park panelboard that is to supply the pedestal. Supply the pedestal with one black 8-gauge wire, one red 8-gauge wire, one white 8-gauge wire and one green 10-gauge wire. Connect the red wire and the black wire to the two terminals of the 50-amp breaker. Connect the white wire to the neutral bus and the green wire to the ground block inside the panelboard. Remove the 50-amp breaker for the duration of the project.
Remove the dead-front panel of the pedestal. Remove knockout panels as necessary to run your wires into the pedestal, and insulate the holes with rubber grommets.
Connect your wires to the rear of the 50-amp socket unless otherwise instructed by the literature delivered with the pedestal. Connect the black wire and the red wire to the two hot terminals; conventionally these terminals will be at three o'clock and nine o'clock, and their orientation is unimportant. Connect the white wire to the neutral terminal, conventionally at 12 o'clock, and the green wire to the ground terminal, conventionally at six o'clock. The terminals will be clearly marked with embossing in the case of the outlet.
Confirm that the new pedestal has pre-installed wiring from behind the 50-amp outlet to the 30- and 20-amp outlets. If it does not, consult the manufacturer's instructions supplied with the pedestal and learn the preferred wiring methods for connecting the outlets; typically it will be a simple series connection made using matching colour-coded wires from like terminal to like terminal.
Connect pedestal lighting, cable television and Internet hookups if the pedestal accepts them and the park provides the latter two.
Reinstate the dead-front panel, reinstate the 50-amp breaker, switch the circuit on and use a test meter to test every function at every outlet.
National Electrical Council, or NEC, regulations mandating the provision of temporary power state in part: "All branch circuits shall originate in an approved power outlet or panelboard... All receptacles shall be of the grounding type... Suitable disconnecting switches or plug connectors shall be installed to permit the disconnection of all ungrounded conductors of each temporary circuit... Every recreational vehicle site with electrical supply shall be equipped with at least one 20-ampere, 125-volt receptacle. A minimum of 5 per cent of all recreational vehicle sites with electrical supply, shall each be equipped with a 50-ampere, 125/250 volt receptacle..." It is imperative that any works carried out on an electrical box in an RV park subscribe to the full provisions of the NEC regulations. Some pedestals are equipped with integral meters, and some with integral breakers. If either is the case, consult the manufacturer's instructions concerning the routing of the hot wires.
National Electrical Council regulations allow for a five-percent drop in voltage between the load centre and the most distant connection to the circuit. If the pedestal is supplied with less than 115 volts or less, this will have to be addressed before any RV is connected to the pedestal. Overloading a pedestal will almost certainly incapacitate any other pedestals further down the supply line. This could plausibly result in damage to the circuits and appliances in other RVs, and even fires. Only install an updated pedestal if the RV park has confirmed that the system can safely and reliably accommodate such a change. It is not possible to upgrade a 30-amp supply to a 50-amp supply. If only 30-amp power is delivered to the pedestal from the campground panelboard, attempting to reroute wiring so that a 50-amp RV can be supplied will result at best in low amperage delivery to the RV's appliances, and at worst destroyed circuits and a risk of fire in the feed system serving the pedestal.