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Solid-state Relay: Short Circuit

FAQ No. FAQ03628

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Solid-state Relays Output Short-circuit Malfunction 2: What cause an Solid-state Relays output to short-circuit?


An overcurrent flowed through the Solid-state Relays output and damaged the output elements.

Possible Causes:

1.A short-circuit occurred due to condensation, deterioration of load insulation, temporary short-circuit, or human error.

2.Solid-state Relays were connected to a load with high inrush current, or the current flow within the circuit configuration exceeded the rated withstand surge current for each Solid-state Relays.

3.A surge voltage was caused by the load power supply, or other loads connected to the load power supply line.

4.Solid-state Relays were used for an extended period of time in an environment subject to temperature increases.

The rated ON current depends on the ambient operating temperature, type of Solid-state Relays, and whether it has a heat sink. (Refer to information on the load current vs. ambient temperature rating for each Solid-state Relays.)

The heat radiation efficiency depends on how the Solid-state Relays were mounted to the control panel. (Refer to information on mounting Solid-state Relays.)