Connecting 2kW generator to distribution board

[Cupatea]

Im registered MCS installing PV systems and have come across a client who would like to connect his 2kW standby generator to his distribution board to power the lights & freezer during a power outage. There are no other alternative supplies installed.

The only way I can see how it would be done is to install an RCBO in the board wired to an AC isolator that is wired to an external commando type socket for the generator to be plugged into when required. The obvious notices & labels re alternate supplies etc being applied.

In practice, when power fails, the main incoming isolator would be turned off, the MCBs to the required circuits left on, the others off, the RCBO on. Power up the generator, plug it in and turn on the isolator.

When main power is restored, the RCBO, isolator and generator are turned off before throwing the main switch.

Is this an acceptable set-up. Is anything else required? Or should I walk away from the idea?

Ta

 

[Mork]

Back feeding an installation isnt a good idea, are you going to rely on your customer to go through the right sequence of events to have a safe stand by system? Walk away and tell him to get the job done properly.

 

[Engineer54]

Don't do it!! Generators of this size will not have a voltage regulator incorporated, speed will rise and fall (as will the voltage) depending on the load applied and are totally unsuitable for a domestic appliance hook-up. These Genny's are only any good for site power tools and lighting. Check with the manufacturer, who will tell you exactly the same as i just have!! You need a generator that has a fully stabilised means of voltage regulation, to hook-up to a domestic installation. You will also need a 3 position change over switch, (utility/ off / generator) among other modifications....

 

[ipf]

Thought about your earthing ? Sounds complicated besides. Some think we can click our fingers and......

 

[benji]

been there and done a similar set-up (they wouldn,t buy a c/o switch warned them it would bite them back ) but they insisted only 1 man would do the switching, went ok till the 1 man wasn,t there and the power went off end result blew suppliers fuses had to get replacements from lawsons and c/o switch from newey,s

 

[ipf]

Give 'em a torch and a few candles

 

[Engineer54]

been there and done a similar set-up (they wouldn,t buy a c/o switch warned them it would bite them back ) but they insisted only 1 man would do the switching, went ok till the 1 man wasn,t there and the power went off end result blew suppliers fuses had to get replacements from lawsons and c/o switch from newey,s

Dammed lucky that's all that blew, ...very lucky in fact!! You saying that it didn't take out the diode set??

 

[kingeri]

You certainly can't feed into a commando socket (think about it)! Changeover switch is the only way to go, so there can be absolutely no cock-ups. And as Eng said, an actual suitable generator would be helpful!

 

[benji]

it was an old fare ground generator on wheels can,t remember the size about 100a per phase 35mm 4c swa (the company was a M&E contractor ) it was early 70s i think

 

[Engineer54]

You don't seem to be saying too much cupatea?? lol!!

 

[ipf]

You don't seem to be saying too much cupatea?? lol!!

Havin' a brew, maybe ? lol

 

[Engineer54]

Thought about your earthing ? Sounds complicated besides. Some think we can click our fingers and......

A small 2KW Genny, will almost certainly have a floating earth arrangement, which just makes things a little more difficult, if your wanting to hook up to an existing earthed installation. The bottom line, taking all the constraints into consideration, this is a very bad idea to hook up to a domestic installation. Only an out and out fool would even think about doing so, after knowing all the facts of the downsides etc!!

 

[ipf]

A small 2KW Genny, will almost certainly have a floating earth arrangement, which just makes things a little more difficult, if your wanting to hook up to an existing earthed installation. The bottom line, taking all the constraints into consideration, this is a very bad idea to hook up to a domestic installation. Only an out and out fool would even think about doing so, after knowing all the facts of the downsides etc!!

Here, here. Dead right.

 

[Cupatea]

I think i'll walk from this one and offer an extension lead to run the freezer. I quite like my intact public indemnity insurance! How big are the 3 position changeover switches? I imagine larger generators have the facility for voltage regulation/ inversion?

 

[Clive P]

Hi,
There are some good Gas Generators around which come with their own Automatic Change Over Panel. They are designed for domestic use and can be installed outside the property. I have used a few of these, no way would I like to use a standard generator, as E54 says, problems,problems,

Regards.