Fire Retardant SSR Enclosures

NO-NC SSR Plastic Box

This was a Fire Retardant Plastic Box which was made for the SSR I/O Stackable Modules. DC Control for an AC Load. Usually it is to control another Big Three phase contactor; Pneumatic or Steam Valve, Solenoids-Motors.

When Mounted at the end of the PCB it offers over 2kV Isolation from the Digital Circuits. The Output 230V signals NO-NC, can control Light Loads like the Coil of a Big 230V Relay also called contactor.

It could be Mounted on a PCB by soldering or a Plugin Base. It is better to have Crimped connections or Terminals. A very good quality spring Loaded Socket may also work but it has to be rated for many operations. Things like Nickel Alloy Plated, Beryllium Copper were the Materials Jargon. A contact resistance in the Terminals, a mismatch of alloys, electrochemical reactions, Corrosive Fumes, Brine or High Humidity can build a Loose connection into a Dangerous Sparking Contact.

Not only the Functionality of the SSR will be affected in a Sparking Contact, but a Risk of a Fire Developing. When Inflammable Materials or Volatile Liquids are Present Nearby, the risk is even greater. Read More - Solid State Relays SSR.

PCB SSR Module


This is a PCB Mount SSR for Control of a Small AC load like a Lamp or a Contacter. It has Optical Isolation and has a Thyristor for output. The MOC3041 A zero crossover optical triac driver is used here. The footprint is very small, many can be stacked in one small PCB.

Read More  - PCB AC Load SSR with DC control.

Standard Power SSR Plastic Box

This is the enclosure for the Encapsulated Mini RTD PT100 Transmitter and also Solid State Relays - SSR.

Potted, Encapsulated in epoxy, hermetically sealed. It has a Nickel Plated Aluminum Plate insert molded. For removing heat from BTA41600.

The plastic is a fire retardant high temperature grade. The epoxy is ciba araldite, fine alumina is filler. A transparent terminal cover for safety. It costed me an equivalent of 600-700 USD for tooling plastic parts.