Back up generator on domestic

[growler]

A customer has asked me to connect his back up generator 'properly' as currently he just flicks the main switch and plugs straight into the down stairs ring main.
I admit I have little experience with this and won't take it on unless I'm 100% I'm doing it correctly. It's a 5.5kva generator on a tt.
Can somebody help me with what I need to consider ?
So far I'm thinking
- change over switch
- earth electrode

 

[shanky887614]

This is why I asked. We used automatic earth transfer switching to the common earth bus. The bus grounded via a NER.

Whats a NER?

Im curious after what happened today.

Do you normally use buz bar changeover switches usinh castel keys?

Is this more an industrial application or common?

 

[Engineer54]

This is why I asked. We used automatic earth transfer switching to the common earth bus. The bus grounded via a NER.

Ah, i should have realised you were talking about MV, yes we use NER's on MV gensets, even on single units, to reduce the available fault current...

 

[Engineer54]

Whats a NER?

Im curious after what happened today.

Do you normally use buz bar changeover switches usinh castel keys?

Is this more an industrial application or common?

NER = Neutral Earthing Resistor!!

I rarely use castel key's on our installations as they are all fully automatic, on both the MV and the LV Switchboards, as i tend to work on large hospital installations. Only ever use them on the downstream MV side, when distribution is via RMU's....

And yes, you could say this is found more within the Larger commercial and industrial sectors...

Tony has used mechanical castell and other interlock key system far more than myself

 

[Knobhead]

Shanky, It’s mainly industrial. Unlike E54’s systems ours were all manual switches.

A typical situation would be two incoming supplies and a bus section switch.
Three locks, two keys. This would give you three options:
Supply A & B CLOSED bus section switch OPEN
Supply A CLOSED bus section switch CLOSED Supply B OPEN
Supply B CLOSED bus section switch CLOSED Supply A OPEN
You can’t parallel supply A & B

There are ways around this. I have a couple of Castell master keys. These were kept locked away at all times and never left my sight.
I just know E54 will shout at me for this.

 

[Engineer54]

Shanky, It’s mainly industrial. Unlike E54’s systems ours were all manual switches.

A typical situation would be two incoming supplies and a bus section switch.
Three locks, two keys. This would give you three options:
Supply A & B CLOSED bus section switch OPEN
Supply A CLOSED bus section switch CLOSED Supply B OPEN
Supply B CLOSED bus section switch CLOSED Supply A OPEN
You can’t parallel supply A & B

There are ways around this. I have a couple of Castell master keys. These were kept locked away at all times and never left my sight.
I just know E54 will shout at me for this.

No not at all, they are in the hands of someone that KNOWS what they are doing!!

 

[scammell man]

I still have some castell master keys. Which apparently don't exist :smiley2::smiley2::smiley2:

 

[Knobhead]

Still got mine even though I'm retired. No one will get their hands on them.

 

[Knobhead]

No not at all, they are in the hands of someone that KNOWS what they are doing!!

You shouted at me for paralleling two 1600KVA transformers and exceeding the boards maximum fault current.
Two guys working together, one on the each ACB. It will take me longer to type “OPEN” “CLOSE” than it took for the switches to operate. We would have been damned unlucky for a fault to occur in that split second. I did take the precaution of putting the 11KV on to one feeder, that needed my 2[SUP]nd[/SUP] naughty key.

Normal operation A, B, D, E closed C & F open.

 

[scammell man]

Standing instruction is to never potentially over stress equipment, even for switching time, except in exceptional circumstances that are fully risk assessed and appropriate action taken. This would certainly include preventing any access to switch gear etc

how did you know you had exceeded the boards max fault current in your example? You can't just add the fault currents together!