The reason why the heating tube needs a relay

When industrial control motors are started and stopped, AC contactors are usually used. The heating equipment and heating tubes in the workshop are all controlled by solid-state relays. Why not use contactors?

If there are no special requirements for low-power heating tubes, they can be controlled by contact contactors, and the heating is controlled by the attraction and bounce of the contacts, which is low-cost and relatively affordable. However, the mechanical contacts of the contactor are noisy, and frequent actions are easy to interfere with surrounding lines and equipment, and the service life is short.

The heating tube solid-state relay (solid-state relay) is referred to as SSR. It is a contactless switching device composed entirely of solid-state electronic components, which can achieve the purpose of connecting and disconnecting the circuit without contact and spark. No noise, no spark, no electromagnetic interference, long service life, faster switching speed than contactors, and better temperature control effect.

It is recommended to use solid-state relays. It should be noted that when using solid-state relays, a heat sink must be provided. When installing, silicone grease should be applied to the SSR base plate first. When the ambient temperature is high, a cooling fan should be provided.