Testing a DC/AC Solid State Relay (SSR)

Don’t Use a Multimeter #

When you are testing an AC SSR you cannot use a standard multimeter to do so. The SSR also uses AC power to operate the entire circuit. This means that just testing resistance across the 2 switching terminals with NO AC load on them will result in odd and/or high resistance readings on your multimeter even if you have the DC side powered.

“A multimeter determines impedance by injecting a small amount of voltage through its probes into the circuit being tested. It then measures the current flowing through the probes and calculates resistance.”

“The voltage and current produced by a multimeter is not sufficient enough to turn on the SCRs, the output of a solid state relay will remain in the off state; even with the input signal applied.”

Crydom – Solid Statements – Bench Test an SSR

Test with a Real AC Load #

Testing an AC SSR is as simple as attaching a load to it (this can be your AC bed you are installing or a lightbulb). See the full detailed technical article from Crydom below for a deep-dive on properly testing your AC SSR.


Crydom SSR Testing Doc 363.08 KB 7 downloads #


Source: Crydom – Solid Statements – Bench Test an SSR

Updated on July 17, 2022
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