PowerMax PMTS30LK Transfer Switch, 50A

Designed for use in RVs with 30 Amp (120Vac) or 50 Amp (240Vac) service. When plugged into the shore power, it will automatically provide AC power to all AC appliances. To operate your appliances from an onboard generator or alternative Power source, simply start them, and PMTS 30A or PMTS 50A will automatically transfer the electrical power to AC appliances. They also feature a time delay of 20-30 seconds to allow the generator voltage to stabilize.