Hi,
I need to connect an inverter & battery for my house.
It needs to run 4 lights, 2 Fans, I TV with set top and a fridge when the power goes?

Is a 1.2 KVA Invertos sufficient for 6-8 hours back up?

Secondly can I directly connect it through mains or is a separate wiring required for this?

Regards,
Rahul Agarwal

 

A refrigerator draws a HUGE current when its motor starts. The inverter might not produce that much current.
The TV and set top box might rely on the high peak voltage from a sinewave inverter and maybe will not work from the square-wave from a cheap inverter.

1200VA is not much power. You must add up how much power you need.
Then the inverter must be rated for continuous running (not momentary peak power) at that amount of power output.

The inverter does not determine how long it can supply the power, the size of the battery does.

You must disconnect the products that the inverter powers from the mains so that your inverter does not try to power your entire city and so your inverter does not blow up when mains power returns.

 

Here's what you need to do:

Look at everything you want to run. Find out how much power it needs. This may be on the back of the fridge or the TV. The internet helps too.

BTW, those lights? A 100 watt bulb needs... well, 100 watts to run. Compact florescent bulbs need lots less.

Total them up. THAT is how big the generator needs be. Get a bigger one anyway.

Now those batteries: if you drain a battery every night it will not last long. The less you draw the longer it will live. 25% of capacity is a good area to hit.

So... take the power you found, divide by 12.6 (the battery voltage), multiply by 6 or 8 hours. You now know how many amp-hours you need.

Buy a battery rated 4 times that.