Solid State Relay HEATSINK

Thread Starter

Dritech

Joined Sep 21, 2011
901
Hi all,

I am planning ti use a SSR to turn on an appliance which consumes 1100W at 240V.
The appliance will be turned on for about 1.5 hours each day.
The SSR is an OMRON G3NA-240B 40A 200-240V.
Is it possible to use the SSR for this application without a heatsink?
 

Alec_t

Joined Sep 17, 2013
14,280
I'm surprised. The triac in the SSR will drop about 1.6Vrms, at a current of ~4.6A, so will dissipate ~ 7.3W. I would have expected that to require a substantial heatsink. But if the manufacturer says it's ok ......
 

Thread Starter

Dritech

Joined Sep 21, 2011
901
EH I missed that part. Thanks for the reply.

I will be using the SSR with a timer to turn off the supply of an ironing machine after a pre-set time.Is there something I must be concerned about?

Also, the ironing machine consumes 1100W at 240VAC. That makes it consume about 5A right? so no heatsink will be required.
 

AnalogKid

Joined Aug 1, 2013
10,986
Correct, but that assumes that the relay is mounted in free air. If it is in an enclosure of any kind, long term reliability will decrease.

That is a full size SSR package with a large heat conducting surface on the bottom. An acceptable heatsink would be just bolting it to something metallic that normally is cooler than the relay is when operating.

ak
 

#12

Joined Nov 30, 2010
18,224
What AK said.
It depends on the size of the case.
Seven&1/3 watts with a radiating surface of 4.5" x 2.28" x 1" (approximately).
Over 10 square inches per face (Not including the 1 inch sides).
Think for a moment.
That's a lot more radiating surface than a 10 watt resistor.
 
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