Solid State Relay Heater Control Circuit

The relay is equipped with a built in synchronization circuit in order to achieve phase angle control.

Solid state relay heater control circuit. Unlike emr electromagnetic relay that has a coil mechanical switch physical contacts the ssr relay uses optocoupler to isolate the control circuit from the controlled. There are many circumstances in which we need to control a high current voltage load based on the operation of a low power circuit such as when using the 5v output of a microcontroller to turn on a 10a 240v load. I put the cover on the unit after. The output is proportional to the input signal.

Since the 4 20ma or 0 10vdc control input of the analog relay can be varied the output operates in accordance with the phase control principle. The solid state relay circuit consists of. Three phase solid state relays their application in three phase heating circuits by paul bachman fellow engineer dr. An ssr is preferred for the normal quick cycling of the heater for temperature control.

A solid state relay ssr is an electronic switching device that switches on or off when an external voltage ac or dc is applied across its control terminals. Oscar montero r d manager and doug sherman fsae manager crydom inc. This a is a legal requirement for industrial ovens in the u s. The principle of operation of a solid state relay is the closing or opening of contacts.

These solid state relays are compact to save space and have a mounting foot that can snap onto a mounting rail or be screwed onto mounting plates. To commutate the inductive load with a solid state relay you should increase the current reserve by 6 8 times. Solid state relay ssr is an electronic switching device made of semiconductors that switch on off a high voltage circuit using a low voltage at its control terminals. Ssrs consist of a sensor which responds to an appropriate input control signal a solid state electronic switching device which switches power to the load circuitry and a coupling mechanism to enable the control signal to activate.

High power solid state relays g3ph high power load control ssrs with high current of 75 or 150 a and high voltage of 240 or 480 vac solid state relays with built in current transformer g3pf. Ssr s usually fail in the on state so for safety a two pole electro mechanical contactor should be in the heater circuit which is controlled by a latching over temperature controller. Three phase solid state relays ssrs have been available since shortly after the introduction of single phase ssrs in 1970. This article provides an introduction to the basic operation of solid state relays with a focus on the output devices in today s ssrs.

I found some high current solid state relays and used one to control the electric heater at home with a digital thermostat.