Single pole up front RCD

[Deleted account]

Situation.

Domestic TNS

Main consumer unit fed direct to incoming.

it has an upfront single pole RCD works fine. No main switch. No double pole isolation available.

Is this a potentially dangerous situation due to single pole Isolation?

I feel I can’t bring myself to give a C2 on an EICR, but equally I want to Tell customer to remedy this.

also it’s a Hager RCD in a steeple board, but the fit is good so was not going to code that.

bad design. Yes. But bad Design isn’t worth a code.

 

[telectrix]

what's a single pole RCD? never seen one.

 

[Deleted account]

what's a single pole RCD? never seen one.

Sorry wording wrong. It does have two poles. However when tripped only the line is isolated.

so single pole isolation.

 

[telectrix]

can't be. a normal RCD trips and isolates both poles.

 

[Deleted account]

When I tripped the RCD the line to neutral on the supply side obviously 230:volts.

on other side obviously no voltage.

but between incoming live and neutral on the other side 230volts,

so came to the conclusion the neutral was open.

however ive just realised what a berk I am of coarse the neutral on the inside is connected to the neutral bar which in turn is connected to multiple circuits some of which will have natural and designed earth leakage. Thus an alternative path to earth.

 

[pc1966]

Try with volt tester, a few mA to drive the LED(s) should confirm if it is "full volts" and really not isolating, or weak/none indicating capacitance as you say.

 

[Deleted account]

Try with volt tester, a few mA to drive the LED(s) should confirm if it is "full volts" and really not isolating, or weak/none indicating capacitance as you say.

I was getting full 230 volts.

 

[pc1966]

I was getting full 230 volts.

Interesting, that is beginning to sound a bit more serious.

While I would very much doubt that an incomer style RCD would be single-pole switching, it is not beyond possibility that one pole has stuck.

I guess you could check for N-E faults on the installation (though I would expect that to be RCD-tripping if an actual short and not a few kOhm or similar from wet dirt).

 

[Deleted account]

Interesting, that is beginning to sound a bit more serious.

While I would very much doubt that an incomer style RCD would be single-pole switching, it is not beyond possibility that one pole has stuck.

I guess you could check for N-E faults on the installation (though I would expect that to be RCD-tripping if an actual short and not a few kOhm or similar from wet dirt).

my Bad my approved voltage indicator is just reading extra low voltage. just lighting up,the 12V led .

Your spot on right.

i heard the continuous tone saw lights on voltage indicator light up and presumed it was 230V.

 

[Lister1987]

I seem to recall a reg somewhere along the lines of if an RCD is to be operated by normal persons them it must be double pole, not single. Whether that offers an bearing I dunno.

 

[pc1966]

If it is the main isolator it has to be double pole

 

[Deleted account]

I seem to recall a reg somewhere along the lines of if an RCD is to be operated by normal persons them it must be double pole, not single. Whether that offers an bearing I dunno.

Think your right. Just hav8ng a blonde moment.

 

[Lister1987]

Think your right. Just hav8ng a blonde moment.

Found it, although it may not apply here

462.1.201
A main linked switch or linked circuit-breaker shall be provided as near as practicable to the originof every installation as a means of switching the supply on load and as a means of isolation.

A main switch intended for operation by ordinary persons, e.g. of a household or similar installation, shall interrupt
both live conductors of a single-phase supply