TLT automatic change over switch is used to automatically switch between generator and PHCN, it shuts down the generator when PHCN power is available and switch over to PHCN power. It is rated in 40Amps, 80Amps and 120Amps which are used for maximum of 8KVA, 16KVA and 24KVA respectively for single phase and 3 phase generator.

The electrical load or generator size of a user determines the type of change over switch, for a user who does not use AC or have a generator below 8KVA, he can use the 40Amps system while someone using 1 or 2 AC can use the 80A system, 120A system will support 3 or 4 AC.