Maker Pro
Maker Pro

Ssr circuit to control fridge compressor

Stryped

Sep 17, 2023
2
Joined
Sep 17, 2023
Messages
2
Hello, I am a relative newbie and wanted to as for help with a circuit design.
I have a fridge/freezer with a dead inverter controlled compressor. I was thinking of using an Ssr connected to the ac voltage going to my condenser fan to trigger a regular compressor. (The type that has its own relay and overload device).
The compressor normally runs on just 2 to 5 amps. However it is rated for 15 LRA. I have been reading and am a little confused. Something I read indicated this would be considered an inductive load and the Ssr should be rated at 6-7 times the load. Does that mean I need a 90 amp Ssr?
One concern I have is the main board is what sends 120 v to the condenser fan. Would the Ssr cause excessive resistance or voltage that would damage the main board?
Another thing I read is inductive loads should use a random turn on Ssr. I have found it extremely difficult finding an ac to ac Ssr that is random turn on. Where would you go to find one if that is what I need?
Lastly, also reading about circuit and Ssr protection. Read about putting a mov across the terminals of the Ssr but having a little trouble understand the selection of the right one that won’t fail closed. Also for protection, would you use any resettable circuit breaks in line with the compressor or thermal cut out?
I apologize for the questions. Any help is appreciated!
 

Attachments

  • Refrigerator.pdf
    4.1 MB · Views: 1

bertus

Moderator
Nov 8, 2019
3,393
Joined
Nov 8, 2019
Messages
3,393
Hello,

There are some precautions you can take.
See the attached PDF for more info.

Bertus
 

Attachments

  • precautions_ssr.pdf
    2.7 MB · Views: 6
Top