ATS Switch Backup Power Indicator Light

Thread Starter


Joined Apr 20, 2020
Hi, I have built an ATS Switch form an Relay to switch between my grid supply and inverter. I am looking for a way to turn on an indicator light when my ATS Switch has switched over to Backup Power.

I already have a Indicator Light on The Mains and Inverter input, but need a 3rd & 4th one to indicate that the switch is using the inverter or if its using the Mains power.

Indicator 1: Mains Power Available
Indicator 2: Inverter Power Available

Indicator 3: Mains Power is being used currently
Indicator 4: Inverter Power is being used




Joined Oct 28, 2019
Whilst youcan use a single relay for a transfer switch, its usual to do this with two relays
You then get three states - grid supply, off, inverter supply
Once you have two relays, you can us auxiliary contacts on the relays to do the indications that you want.