ST4-M1

The ST4-M1 is a 4-channel sequential timer designed for controlling loads in a fixed sequence — one after the other — with defined ON and OFF time periods for each channel. Ideal for switchgear panels, dust-collection systems, air-handling units, pneumatic conveyors and other automation applications where equipment needs to be started/stopped in sequence without overlap. 

Key Features

• Four independent channels (CH1 to CH4), each with its own relay output.

• For each channel: programmable ON-time and OFF-time (timer range typically from 0.1 seconds up to 1 hour for each ON/OFF period in the standard variant). 

• Supply voltage: Standard version 240 V AC.

• When power is interrupted, the unit supports either “HOLD” mode (continues timing where it left off) or “RESTART” mode (resets to channel 1 or waits for start signal) — selectable. 

• Start signal (terminals S1-S2) via a potential-free contact (shorting S1–S2 triggers the sequence) — the timer waits for this to initiate the sequence after each full cycle or after power-up.

• After channel 4 completes its OFF-time, the sequence automatically returns to channel 1 and repeats (in cyclic mode) unless configured for single-cycle mode. 

Applications

• Sequential startup of fans, blowers, motors, or other loads to reduce inrush current and avoid simultaneous load switching.

• Industrial systems such as baghouse filters, dust collectors, pneumatic conveyors, air-handling units where loads must come online in a defined sequence.

• MCC (motor control centres) and control panels where simplified sequential load control is required without the complexity of PLC logic.

• Retrofitting into existing systems where a compact sequencer is required, and where panel space or complexity is limited.