40A 3-phase 3-32V DC to AC solid state relay (SSR-40DA) features high structural strength, good impact resistance, and strong shock resistance. The SSR relay offers a reliable switching the commercial and industrial loads, such as computer peripheral interface device, printing machine, molding machine, food machine, packaging machine, and so on.
- Built in RC absorption
- Photoelectric isolation
- SCR output
- LED indicator for operation status
- Removable protective cover for safety
- Panel mount
- Zero-crossing switch type
||Control voltage range
|Max. input current
|Must operate voltage
|Must release voltage
||Load voltage range
|Maximum load current
|Maximum off-state leakage current
|Maximum off-state time
|Maximum on-state voltage drop
||DC to AC, 3 phase
|Dimension L – W – H (mm)
|Dielectric strength (input to output)
|Dielectric strength (input, output to the base)
- When the load is a resistive load, the maximum load current of the selected SSR should be 2~3 times greater than the actual load current;
- When the load is an inductive load, the maximum load current of the selected SSR should be more than 7~8 times the actual load current.
- When the maximum load current is higher than 10A, a heat sink must be installed to the solid state relay, or the SSR relay should be mounted on a metal base plate with heat dissipation effect, and the thermal grease is applied between them.
Dimensions (Unit: mm)
Tips: Thermal design and radiator selection of solid state relay
There is certain internal power dissipation in solid state relays’ operation. The dissipation value is mainly determined by product of output voltage drop and load current, embodied in the form of heat radiation. The quality of heat dissipation directly affects maximum load current of solid state relays and maximum allowable temperature of the working environment and it is one of the important factors that affect the reliable operation of SSRs. Therefore, we should pay attention to thermal design and radiator selection so that SSRs may work reliably and failure of and damages caused by poor heat dissipation to solid state relays can be avoided.
In general, solid state relays, whose output current is less than 5A, use natural convection air enough to achieve the purpose of cooling, but when installed, solid state relays need a good convection environment and the space between each solid state relay should not be less than the width of a SSR. It is essential for those solid state relays with a load current greater than 10 A to use suitable radiators, even forced air cooling (air speed at 6 m/s) or water-cooling if necessary. The good heat dissipation condition is very important for SSRs’ reliable work.