How to set up a portable generator to provide back up power?

You can use a portable generator for emergency backup in a couple of ways. Let’s imagine you have a power cut. Bother. Now what to do? We can offer  two scenarios.

1. This scenario requires a standard portable generator and the size depends on what you are going to power with it.

You have a your portable generator stored in the shed. You take your torch, go and fetch the generator, fill it with petrol, take it somewhere outside – a minimum of 10ft from the house. Then you run a heavy-duty cable into the house and plug whatever you need into a heavy-duty multi-gang. This will not, of course, power ceiling-lights, or electrical sockets.

N.B. You must never have the generator running inside your dwelling or a room you will be staying in, due to carbon monoxide petrol fumes. You could run the generator from an outhouse, but you will have to create some kind of exhaust venting and air intake for cooling, even open doors. A generator should not be shut running inside a shed with the doors closed. Make sure you don’t use ordinary household cables, particularly outside. You’ll need to invest in good-quality, shielded, weatherproof cabling to take the power into your home.

2. This scenario requires a larger more powerful portable generator.

You go and get your portable generator and you plug into the mains to replace the mains power. The same rules apply regarding cabling and using the generator outside, using good-quality cabling etc, but there is little more to it than that because this solution requires some work by a qualified electrician. The generator MUST be isolated from the mains supply for safety and efficiency. Otherwise, power can back-feed along the lines and you could electrocute the poor chap down the line trying to fix the mains supply, or even give a nasty shock to your neighbours. So make sure a manual transfer switch is installed by a qualified electrician. This is fitted between the meter and the consumer unit, connecting the building, and you plug your lead from the generator into an inlet connector.

N.B. You will also have to have an RCD (Residual Current Device) fitted if you don’t have one already. This is a safety device built into consumer units in many buildings. Your generator will need modifying to utilise this. Again, a qualified electrician will need to do this. Finally, a low impedance earth spike will also need to be installed so, as a general note, DO NOT attempt this second solution without at least a long talk with a qualified electrician. It will be worth it, and is essential for safety. This is a viable and useful way of providing backup power and gives you the flexibility to use the generator for other purposes, since it is not permanent.

And, in case we didn’t make it clear… …

ALWAYS TALK TO A QUALIFIED ELECTRICIAN BEFORE SETTING UP A GENERATOR THIS WAY