Heat Sink Fins should be in vertical position.
So that hot air flow from bottom to top - self
cooling
Keep 20mm gap at top and bottom of heat sink.
Apply Heat Sink compound between SSR and
heat sink
The screw should tight properly so no air
gap between SSR and Heat Sink
1800 Square mm of total exposed aluminum
is sufficient to dissipated one watt of heat
generated
Tj TA
= P(ØJC+ØCS+ØSA)
Tj
=Junction Temperature (°C) 125 °C
TA
=Ambient Temperature(°C)
P
=Power dissipation (wattes)=on state
voltage drop X load current
ØJC
=Thermal resistance junction to case
ØCS
= Thermal resistance of Heat sink compound
(0.2°C/WTYP)
ØSA
Thermal resistance of external
heat sink (°C/W)
If SSR current capacity
high and SSR use for lower capacity of load current
than heat sink size will reduced Example:
1). 50Amp SSR used for 15Amp Load Current than “B”
Type of Heat sink.
2). 50Amp SSR used for 25Amp load current then “C”
type of Heat Sink.
