Solid State Relay Heat Sink for Industrial SSR/3-Phase SSR

This aluminum heat sink radiator is suitable for one or three pieces of industrial-grade single phase solid state relay or one piece of three phase solid state relay.

Note: The below actual load current is calculated based on that the heat sink is installed with a cooling fan (38*120*120mm) at the one end, and the length should be increased by 38mm after the fan is installed. The cooling fan (Power supply 24VDC / 110VAC / 230VAC) can be selected in the drop-down list of Accessories.

Specification

Dimension (Unit: mm)

Tips: How to Select a Suitable Heat Sink for a Solid State Relay or Module?

Actually, there is no fully consistent relationship between them, because the heating value of the solid state relay or module is mostly related to the actual load current, but not to its own the current rating. Calculation formula of heating value: 

1. Heating value = Actual load current (A) × 1.5W/A
The formula is applicable for single phase solid state relay, single phase AC voltage module and R series solid state voltage regulator. For three-phase solid state relay and three-phase AC voltage regulator module, the actual load current shall be the sum of three-phase actual load current.
2. Heating value = Actual load current (A) × 3.0W/A
The formula is applicable for single-phase fully controlled rectifier module.

The function of heat sink/ radiator is to dissipate the heat produced by the solid state relay or module. However, the heat dissipation effect is not only related to the size of heat sink, but also affected by many factors like ambient temperature (season), ventilated condition (natural cooling or force cooling and wind quantity size) and installation density, etc.
Here is a reference standard for heat dissipation: make the temperature of the solid state relay or module base plate (the contact surface with the heat sink) not exceed 80℃. Therefore, in practical application, a 75℃ temperature switch (with a pair of normally closed contact) can be installed in the mounting surface of heat sink near the edge (20mm) of solid state relay or modules, and the control signal of the solid state relay or module is series connected to the normally closed contact. In this way, when detecting the temperature exceeding 75℃, the normally closed contact will jump off to cut off the control signal and force the output of the SSR or module to be closed, so that the SSR or module can be protected. Generally it is best to adopt the temperature switch protection in the case of each phase of the actual current more than 50A, high installation density, and high ambient temperature.
When choosing a radiator, in addition to the above factors, it should also consider whether the size of solid state relay is suitable for the radiator, and whether the installing space of heat sink in the machine is enough or not. In any case, make sure that the bottom plate temperature of the solid state relay or module should not exceed 80℃ even in the worst condition.