Solid state relay, 3 phase, SSR-40AA, 40A 70-280V AC to AC

Features

40A 3-phase solid state relay (SSR) with 70-280V AC to 24-480V AC features high structural strength, good impact resistance, and strong shock resistance. The SSR 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

Specification

Note:

1. 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;
   
2. 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.
   
3. 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)

Wiring Diagram

Tips: Over-current protection of solid state relay

Solid state relays (SSR) take semiconductor switching devices as power output components, and are sensitive to temperature changes. Over-current may overheat semiconductor chips, which results in there decreased quality, life expectancy reduction or even permanent damage. Although solid state relays (SSRs) in an instant can withstand surge current 10 times larger than the rated current, but permanent damages are likely to be caused if the current is more than such a value. Therefore, over-current protection is very important. There are many ways for over-current protection. The key is to fast response. For AC solid state relay with SCR as output devices, general protection circuits are invalid due to current zero required by SCR’s turn-off if the surge current and short-circuit current are larger than SSR’s surge current within 10 Ms (50Hz). At this moment, fast acting fuses exclusive for semiconductor devices. Fuses’ nominal fusing current should not exceed the nominal current value of the SSR. There are a variety of commercial fuses, but their quality is different. Therefore, pay attention when choosing fuses.