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# Help for choosing the correct SSR

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#### Regius

##### New Member
Hi,

I want to control the power of heating elements with arduino and for this reason I'm looking for help for choosing the correct Three Phase SSR.
I'm currently looking at this SSR with Zero Cross Turn-On.
The power grid is three phase: 220VAC Phase Voltage ; 380VAC Line Voltage

What Load Voltage Rating / Load Current Rating of the SSR will be enough (The Load will be in Star "Y" connection). The total power of the heating elements is 12kW.
If this calculations are correct 12 000 W / 220V = 55A
For the load current rating: 75A will be enough?
For the voltage rating: 240VAC will be enough? or i will need the 480VAC version?

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If you have a neutral connected to the load star point, you can think of it as three, single phase loads, each taking 1/3 the total power; a 240V AC rated relay would do it.

Without a neutral, the relay will be switching 380V so you need the higher voltage version.

The load current per phase is roughly 19A

Thanks a lot rjenkinsgb. Now it is clear for me!

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