Connecting a generator to essencial circuits

[spider]

Hi All,

I have a few questions and would like your opinion and advice on please, recently housed local to us have had a power outage for 30hrs, and this got me thinking (dangerous I know) about using a generator to feed essencial circuits.

The house supply is TN-C-S
Crabtree Starbreaker split load CU

What I was thinking is to install a Gewiss GW66004 switched socket oulet fed from a 10A RCBO on the non RCD side of the CU, (The genny is only 2.2kVa)

The genny would be plugged in using a modified plug at the genny end (neutral & earth joined)

Also I would install an earth electrode using 16mm to the CU earth bar

Operation would be:

1 Isolation and locking off of the main incoming supply at the CU when utility power is lost
2 Isolate MCBs except lighting and sockets (loads disconnected except FCU feeding heating)
3 RCBO to genny socket on and backfeed into board

Whats your thoughts, is it feasable.

Cheers

 

[andyh]

Andy,

Save your money and slot this little baby in

YouTube - Double pull Double Throw Changeover switch.divx

Heaven help us! Still makes the rest of us look good!!

 

[spider]

I have read on forums that you are not permitted to install consumers equipment on a meter cupboard board, is this a fact? or urban myth?, if fact, a point of referance would be good.

I have made numerous phone calls trying to confirm or otherwise to my electricity provider and network supplier and both are passing me back an too.

Guidance notes recommend not doing it, but that is all they are, and that is inconsistant!

My generator transfer switch will hopefully live in the meter cupboard if their are no red cards.

Any help would be good

Cheers

 

[andyh]

I have read on forums that you are not permitted to install consumers equipment on a meter cupboard board, is this a fact? or urban myth?, if fact, a point of referance would be good.

I have made numerous phone calls trying to confirm or otherwise to my electricity provider and network supplier and both are passing me back an too.

Guidance notes recommend not doing it, but that is all they are, and that is inconsistant!

My generator transfer switch will hopefully live in the meter cupboard if their are no red cards.

Any help would be good

Cheers

It seems to vary from one DNO to another. That's not much help I know but from my own research there isn't really a definitive answer. I've had a verbal assurance they don't mind provided you don't interfere with their equipment. In essence, for my new build, I bought the meter box which came with the back board. The DNO simply installed the meter and cutout into it. From my point of view, I own the meter box and can therefore put what I want in it provided it's safe and is not against any specific regulation. However the DNO could ask you to remove non standard equipment if they came to inspect or change the meter.

I think you'll find it hard to get a common opinion on this and, as stated, some DNOs allow it and others say no. If I was you, I'd install the switch in the meter box and take the chance. Sounds like you've done your best to confirm what they allow.

Good luck and let us know how the install goes.

 

[spider]

I spoke to EDF (my DNO) several times and they were only interested to the service head, but they would not confirm in writing that is was acceptable (or conversley, that is was not)

Maybe I'm looking to deep into this!

Last thing I want is for the meter reader to flag up a problem, chances are I will fit it in the cupboard.

 

[spider]

Update 5/2/10.

E.ON confirmed over the phone that their would be no charge to move the isolator 3" to make way for a Transfer Switch.

Seimens Meter Man turns up with 'connect & test' on his job card, not move the isolator!, he said that I can't put my equipment in the meter cupboard in case the room was needed for a check meter or economy 7.

Explained that I had made numerous phone calls to confirm or otherwise that it was OK for me to install my equipment and unless EDF have formally adopted my meter box, it belongs to me, and I can put in it what I wished, unless of course he knew differently and could point me to a regulation or supply T&C.

He rang his boss, who said do the job, result Spider 1 Seimens 0


Pics will follow as the switch and ancillary equipment go in.

 

[spider]

Just some more pics of the transfer switch decied after chatting on here that a method to announce that the utility power had restored when running on genny would be a good idea, hence the switch which when in the off position will mute the local 230v sounder.

The switch is a lockable one i.e you have to lift the toggle to allow it to either turn on or off, bit like selecting reverse on your car , this is so it can't be knocked either on or off.

will show you a wiring picci when its loomed nice.

 

[andyh]

Just some more pics of the transfer switch decied after chatting on here that a method to announce that the utility power had restored when running on genny would be a good idea, hence the switch which when in the off position will mute the local 230v sounder.

The switch is a lockable one i.e you have to lift the toggle to allow it to either turn on or off, bit like selecting reverse on your car , this is so it can't be knocked either on or off.

will show you a wiring picci when its loomed nice.

Fantastic setup and very well put together. This is definitely the route I will take. Look forward to seeing the finished switch installed and working.

Will start working on my own now!

 

[spider]

Fantastic setup and very well put together. This is definitely the route I will take. Look forward to seeing the finished switch installed and working.

Will start working on my own now!

Cheers Andy,

Some of the links for the kit used:

PRO SIGNAL|ABI-027-RC|PIEZO BUZZER, MAINS VOLTAGE | Farnell United Kingdom
TYCO ELECTRONICS|FTN59|SWITCH, DPDT, LOCKING | Farnell United Kingdom
230V Green LED for Switch Panel

Expandable sleeving from ebay

If anyone wants the lable template its created in Visio, I can PM it out

 

[andyh]

Cheers Andy,

Some of the links for the kit used:

PRO SIGNAL|ABI-027-RC|PIEZO BUZZER, MAINS VOLTAGE | Farnell United Kingdom
TYCO ELECTRONICS|FTN59|SWITCH, DPDT, LOCKING | Farnell United Kingdom
230V Green LED for Switch Panel

Expandable sleeving from ebay

If anyone wants the lable template its created in Visio, I can PM it out

Thanks for the links. That saves me a lot of time sourcing the components. I'd love a copy of the template. The only thing I might change on mine is putting in a three position rotary switch for Mains, Off & Generator. That means I can isolate all power if I need to work on the main CU. Obviously yours would do this as well if you switch to generator and the generator isn't running!

 

[Reelsaver]

(however it is based on a floating earth)

As your system is a TN-C-S system even when the main switch is open the earth is still connected.
If you connect an additional earth to the star point of the generator (common for island mode operation) you are in danger of introducing circulating currents into the system which could overload current caryying capacity of your main cabling.
As previously postedy others the safest and best way of connecting a generator is via a change-over switch (either manual or automatic)
If your generator is not expected to pick up the full load of the property you could fit undervoltage devices to all non essential circuits, that way when the mains fails the circuits will automatically disconnect; when the generator runs up to speed and closes onto the bus bar only essential cisrcuits are still connected.

 

[spider]

(however it is based on a floating earth)

As your system is a TN-C-S system even when the main switch is open the earth is still connected.
If you connect an additional earth to the star point of the generator (common for island mode operation) you are in danger of introducing circulating currents into the system which could overload current caryying capacity of your main cabling.
As previously postedy others the safest and best way of connecting a generator is via a change-over switch (either manual or automatic)
If your generator is not expected to pick up the full load of the property you could fit undervoltage devices to all non essential circuits, that way when the mains fails the circuits will automatically disconnect; when the generator runs up to speed and closes onto the bus bar only essential cisrcuits are still connected.

I propose to install a seperate earth rod connected via a 16mm conductor to the consumer units earthing bar, the single phase generator will have the neutral/earth tied at the local socket inlet for it.

 

[spider]

Power Transfer Switch Conclusion:

All works now completed on my little project to install a manually operted Power Transfer Swich to allow me to supply the house from a stand-by generator.

If anyone wants any info on this project, just PM me.

Pic 1 : Completed unit in garage, took the oppertunity to change my existing local isolator, MCB & contactor supplying dado sockets for a smaller unit, allowing more room to fit the PTS.

Pic 2: Copper earth rod, 16mm to C/U earth bar

Pic 3: DNO lowered isolator giving more room for me to install the 16A generator intake.

 

[benji]

just looking at the 16a socket is that an inlet socket ? if not that means you will have a standard 16a plug on the cable from the gen. with bare copper pins that will be live when gen. is running ,or is it a 16a female plug on gen. cable

yours benji

 

[spider]

just looking at the 16a socket is that an inlet socket ? if not that means you will have a standard 16a plug on the cable from the gen. with bare copper pins that will be live when gen. is running ,or is it a 16a female plug on gen. cable

yours benji

benji

You are correct it is an inlet socket, As I was going to be the one who sets this up, I didn't factor the senario you put forward, in light of the chance that a shock hazard will exist, I will change this to an appliance inlet socket.


Cheers

 

[benji]

you might have to fit it into your sw.socket as i don,t think they do a sw.outlet socket ,but it will prob. be cheaper to fit one into existing unit

yours benji