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Safety Precautions for All Solid State Relays

Refer to the Safety Precautions section for each SSR for specific precautions applicable to that SSR.


Do not touch the SSR or the heat sink while the power is being supplied or immediately after the power supply has been turned OFF.
Touching the SSR or heat sink while it is hot may result in burns.


Do not touch the LOAD terminals on the SSR immediately after the power supply has been turned OFF.
Shock may result due to the electrical charge stored in the built-in snubber circuit.


Always attach the cover terminal if the SSR has one.
Contact with current-carrying parts may result in shock.


Always turn OFF the power supply before performing wiring.
Not doing so may result in shock.


Do not allow short-circuit current to flow to the load side of the SSR.
The SSR may explode if short-circuit current flows.


Precautions for Safe Use

OMRON constantly strives to improve quality and reliability. SSRs, however, use semiconductors, and semiconductors may commonly malfunction or fail. Short-circuit failures represent the main failure mode and can result in an inability to shut OFF the load. Therefore, for fail-safe operation of control circuits that use SSRs, do not use circuits that shut OFF the load power supply only with an SSR, but rather also use circuits with a contactor for breaker that shuts off the load when the SSR fails. In particular, it may not be possible to ensure safety if the SSRs are used outside the rated ranges.
Therefore, always use the SSRs within the ratings. When using an SSR, always design the system to ensure safety and prevent human accidents, fires, and social harm in the event of SSR failure. System design must include measures such as system redundancy, measures to prevent fires from spreading, and designs to prevent malfunction.

1.Do not apply voltage or current in excess of the ratings to the terminals of the SSR. Doing so may result in failure or burn damage.

2.Do not use the SSR with loose terminal screws.Doing so may result in burn damage due to abnormal heat produced by the terminals.

3.Do not block the movement of the air surrounding the SSR or heat sink. Abnormal heating of the SSR may result in shorting failures of the elements or burn damage.

4.Follow the Precautions for Correct Use when performing wiring or tightening the screws. If the SSR is used with the wiring or screw tightening performed improperly, burn damage may occur due to abnormal heat generated when the power is being applied.