Product Introduction

The TOMZN TO119G / TO219G / TO319G / TO419G series are manual transfer switches (MTS) designed to provide reliable power supply for essential circuits. They serve as a secure bridge between two independent power sources, typically utility power (main source) and a generator (backup source). The primary function is to manually shift the electrical load from a failed or de-energized main source to a live backup source, ensuring continuous operation of critical equipment. A key safety mechanism provides complete electrical interlocking, preventing both power sources from being connected simultaneously, thus avoiding back-feeding, short circuits, equipment damage, and hazards to utility workers. Each switch features a clear "OFF" (middle) position for complete physical isolation, enabling safe maintenance. Operation is direct and intentional with clearly marked positions (I, II, Off), giving operators full control. Available in 1P, 2P, 3P, and 4P configurations with 40A or 63A ratings, these MTS units are ideal for generator and photovoltaic (PV) applications.

Product Data Sheet

Model number: TO119G / TO219G / TO319G / TO419G

Number of poles: 1P (TO119G), 2P (TO219G), 3P (TO319G), 4P (TO419G)

Rated voltage: 230V AC (all models)

Rated current options: 40A, 63A

Type: Manual transfer switch (MTS) / Dual power isolating switch

Interlock: Complete electrical interlocking (prevents simultaneous connection)

Off position: Yes (middle position, both groups disconnected)

Terminal connections (1P): Position I connects 1-2; Position II connects 1-4

Terminal connections (2P): Position I connects 1-2 & 5-6; Position II connects 1-4 & 5-8

Terminal connections (3P): Position I connects 1-2, 5-6, 9-10; Position II connects 1-4, 5-8, 9-12

Terminal connections (4P): Position I connects 1-2, 5-6, 9-10, 13-14; Position II connects 1-4, 5-8, 9-12, 13-16

Wiring flexibility: Incoming/outgoing wires adjustable; for dual power switching, lower in and upper out must be used

Application: Generator backup, photovoltaic (PV) systems, essential circuit transfer