FAQ02152 of Solid-state Relays FAQ

The minimum load currents in the following table can be switched using SSRs with Power MOS FET outputs (G3DZ/G3RZ).

Minimum Load Currents for G3DZ and G3RZ

The following applies to AC SSRs with triac or thyristor outputs and to DC SSRs with power transistor outputs.

SSRs with AC Output:

At present, the minimum load current for most SSRs is 100 mA (50 mA at an ambient temperature of 25°C or higher) considering the degree of current (holding current) required because of problems with the load failing to reset due to leakage current and the output elements remaining ON.

Microloads below these values can be supported by connecting bleeder resistance in parallel with the load. By using MOS FETs, however, microloads can be directly switched without bleeder resistance.

Bleeder Resistance

SSRs with DC Output:

Leakage current may cause the load to fail to reset.

There is generally no problem for most microload switching with SSR models with a leakage current of 0.1 mA or less. Caution is required, however, for SSR G3CN-D, G3FD, G3HD and other models with large leakage current.

The following table provides a rough guide to bleeder resistance if reset failure occurs using the G3CN-D, G3FD, or G3HD.

Bleeder Resistance