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

 

[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

 

[bugsy]

Why piddle about Merlin Gerin do a good package systemwith a UPS at 500kva

 

[wattsup]

I don't get the length of this thread ..why?
A simple changeover switch is all that is needed?
Am I missing something?