DIN rail thyristor controllers for HVAC

Louise Smyth

The newly-extended range of DIN rail mounted thyristor controllers from Power Products International are designed for controlling heater batteries and air duct heaters in HVAC systems, as well as other commercial and industrial resistive load applications such as electric furnaces.

These industry standard controllers are available in single-phase versions with outputs up to 7 kW and three-phase versions up to 28kW, with custom options available. They are self-powered and accept 0-10 Vdc input signals.

Zero crossover switching is used together with burst pulse control, where the load is switched in integer multiples of half mains cycles to minimise supply disturbance and electrical noise. Variable frequency pulse width modulation (PWM) ensures fine resolution control.

"Control of resistive loads using thyristors continues to be widely employed in HVAC heater applications," said Mark Williams, PPI's sales and marketing manager. "Our extended DIN rail mounting range now covers all power options up to 28kW, and the products are available either directly from us or through HVAC industry wholesalers."

Complying with all the relevant EMC and safety regulations, the units are also CE compliant and built to BS EN 50178. They are available from stock, and panel mounted versions with outputs up to 150kW are also offered.