230V 30A Relay to be active after delay of 30 seconds on power failure

Hi All,

Need you valuable assistance for my below issue.

i need to activate a relay 30A 230V exactly 30 seconds after a power failure. ( Generator kicks in after 15 seconds but it will trip off the safety switch if my 30A heater is already On , but no issue once 30 seconds is finished)

So i need Arduino Nano to identify power is down.
Start a delay timer for 30 seconds.
Activate 30A relay after 30 seconds ( from generator power) .

Also suggest me the best way to power up Android nano.

Why not use a standard Arduino relay shield to operate a contactor doing the heavy load.

Use a battery to keep the Arduino operating when power fails.

1 Like

Do you already have the 30A relay? If so, which one (link/url).

And I would personally add a safety margin on the relay specification; 30A heater, 40A relay.

No don't have relay, will buy probably something like the one below in link.

Do you need it to actually operate reliably more than two or three times? Use a real relay designed to operate reliably for your project. Notice there are NO reliability specifications for the device.
Paul

Thank you @Paul_KD7HB for the input. Ill check for a better reliable one.

Debouncing Switches in Arduino has an option to detect loss and gain of AC power input

This project Retrofit Fan Timer with override off and settable time uses it to do the sort of thing you are after.
In that case I keeps the fan running after you turn off the light.
Here is the circuit us uses

1 Like

@drmpf Thank you. Let me have a detailed look to the links.

I think you meant "roughly 15 seconds after power is restored". Until the generator kicks in there's no power for anything, and power becoming available is the obvious signal to time from I suggest.

Perhaps a 555 timer would be enough to do this.

@MarkT Thank you. Any quick diagrams of circuit for this?

Any quick diagrams of circuit for this?

LM555 TIMER MONOSTABLE