EICR on TT, Coding for TP isolators and SP RCBOs

[NorthEastSpark]

Hello,
I'm after some coding advice / opinions regarding EICR of warehouses / offices.
In others opinion would this be agreeable (helplines closed at weekends..)

The units are TT.

Where there is 4 pole 300mA S main switch to DBs, but single pole RCBOs or MCBs are utilised within them, C3?

Where DB from origin, & main switch is 3 pole (fixed neutral) C2
AND RCBOs are single pole also, C2
If the main switch was exchanged for 300mA S 4 pole- the remaining SP RCBOs C3 (no MCBs in this one)

On another, where tails are single insulated before an upfront 300mA, but are in galv trunking, would this warrant a code?
- (in my opinion) there is no way damage could occur.

Some 3P commando sockets don't have supplementary 30mA and are used for fixed equipment only such as roller shutters, chargers (e.g. bolted to the floor)- no code?

Some office areas plastic dado sockets (rings) don't incorporate 2 terminals- there is room for 10 - 20 PCs but they are currently vacant. No code?

Before I'm shot down, I can't recall ever doing an EICR on TT where there haven't been 4P isolators etc.


Thanks

 

[westward10]

There is no requirement for a protective device to isolate the neutral in a TT system.

 

[NorthEastSpark]

There is no requirement for a protective device to isolate the neutral in a TT system.

Thanks.

I've had a bit of a nightmare before fault finding where there has been an upfront 300mA operating, and the DB has been stuffed so full that the N bars are inaccessible and it's very difficult prise anything out of the RCBOs!
- So maybe it should be a requirement ?

I will C2 where isolators are 3P from origin

 

[Deleted account]

I will C2 where isolators are 3P from origin

don’t do much 3 phase, but I’d be curious to know why the C2

 

[NorthEastSpark]

don’t do much 3 phase, but I’d be curious to know why the C2

Sorry, where I've typed 3P i mean 3 pole have been used, as opposed to 4 pole, e.g.
C2 where there is no means of disconnecting the N

Reg 462.2 "every circuit shall be provided with isolation means for all live conductors except as detailed in-
Reg 461.2 (regarding TNS, TNCS)

 

[Deleted account]

Sorry, where I've typed 3P i mean 3 pole have been used, as opposed to 4 pole, e.g.
C2 where there is no means of disconnecting the N

Reg 462.2 "every circuit shall be provided with isolation means for all live conductors except as detailed in-
Reg 461.2 (regarding TNS, TNCS)

thanks just read regs as indicated. Makes sense.

 

[westward10]

With TN systems neutral is deemed to be at earth potential with TT it is not, so if the isolator only disconnects the lines there a possibility of potential difference between earth and the non-isolated neutral.