Three-phase heater banks — on extruders, dryers, ovens and furnaces — are switched more neatly by one three-phase solid state relay than by three single-phase units. Fotek's TSR series switches all three phases from one control signal, in a single compact module.
As with single-phase relays, the code shows current and control type: TSR-40DA is 40 A per phase with 4–32 V DC control, TSR-25AA is controlled by 80–250 V AC, and -H versions handle loads up to 480 V AC.
TSR relays must be mounted on an adequately sized heat sink, ideally with forced cooling in hot panels. We supply TSR relays and matching heat sinks — send the heater power and voltage and we size them.