switching 220V AC with a relay

Thread Starter


Joined Jan 28, 2010
I've got a piece of equipment that's powered by 220V service and I need to remotely switch it on and off from the internet. I've got a nice rack mount 110V power switch with network interfaces and I was thinking I could just wire up a relay to do that job. The following are my newbie questions:

1. I found the omron Z2872-ND relay at digikey.com by searching for a 220V 25 Amp relay with Control Voltage On of 96 VAC. The next higher control voltage in the search form was 150 VAC. Even though the datasheet says (MAX), I presume that's the voltage required to turn on the relay, therefore for a 110 VAC control circuit I should choose the 96 VAC part. Is that correct?

2. The relay has four terminals which I think the control and power wires. Does that mean to switch my 220 VAC service I need to use a relay for each leg of the circuit?



Joined Nov 23, 2009
The 96v is the pick up voltage, the max voltage that the relay will require to actuate. This voltage is always substantially less than the nominal coil operating voltage.

In other words, the coil is rated for 120 input.

You will actually want a DPST switch as that would control both hots of the 220.