Rcbo on a tt system

[Doctor]

Hi Working on a site that was supplied with a tt system, near end of job keeping the tt set for landlord supply.

i put in 3 raidials out side lighting (low watt led).

all back to a 6 amp 30ma rcbo type b

also have 32amp 30ma rcbo type b( that's fine)

 Now the 6 amp rcbo will not test trip when on, but will when the lighting legs are disconnected 

also will stay on but only after 2/3 try's.

each lighting leg has tested fine 

Put each one on separate still no test trip ?

have  or tested the rod yet (Ze)

but will tomo.

just anyone got any ideas if not the rod ?

and yes checked installation is correct 

 

[steptoe]

What's Ra,?

What tester you using? Are you testing correctly,?

Do you know how to test TT systems,?

I do hope they are DP RCBOs,,,,,,, 

PS : you MUST disconnect all load side before testing anyway, so I don't see the problem there.....

Are you trying to test at the terminals,?

What make of RCBOs are they,???

 

[apprentice87]

Installation cannot be correct or it would all be working...

john..

 

[ProDave]

When you say "will not test trip" are you referring to the test button on the rcbo does not trip it, or your rcd tester does not trip it? (or both)
 

 

[Doctor]

What's Ra,?

What tester you using? Are you testing correctly,?

Do you know how to test TT systems,?

I do hope they are DP RCBOs,,,,,,, 

PS : you MUST disconnect all load side before testing anyway, so I don't see the problem there.....

Are you trying to test at the terminals,?

What make of RCBOs are they,???

I have not tested the Ze/Ra yet. 

will be useing fluke multifunctional 

and yes disconnect as per testing.

rcbo's mk.

They are single pole ..... damn

i did not install sub did,

just got a call to site to look at it.

 

[Doctor]

When you say "will not test trip" are you referring to the test button on the rcbo does not trip it, or your rcd tester does not trip it? (or both)
 

Yes test button on the rcbo 

only doing initial inspection broke down each leg of lighting hoping it would be on just one. But think I have it answer above 

 

[Andy™]

so have you actually tested it with a tester?

 

[steptoe]

I just can't get my head around stuff like this, and OP isn't the first time either.

I NEVER leave house without my test kit, ok, maybe not all of it, but as a very minimum my MFT goes everywhere with me, even just to do a lamp change. :shakehead

btw,, if you don't understand TT, which I'm not convinced you do by last post, there is no Ze, let's hope your meter does Ra, and let's hope DP RCBOs fit the board, :|

 

[Doctor]

It's not my test kit and have other staff would be silly to have 20 testers don't you think ? 

Ze/Ra is the term given to the resistanc of the earth fault path.
 

 

[steptoe]

It's not my test kit and have other staff would be silly to have 20 testers don't you think ? 

Ze/Ra is the term given to the resistanc of the earth fault path.
 

I hope at least one of your staff is a competent electrician , 

and that they understand TT systems.

You should get them to have a look at this.

Oh, and make sure they take the test kit,

How on earth were you going to verify this was safe to leave energised,?

And , NO, it is NOT Ze on a TT system.

Ze is impedance to earth, were you sick that day,?

 

[ProDave]

If the firm's only tester was somewhere else, how do you do any functional testing before energising something, or how do you test for dead etc? do you individually carry ANY test kit when the MFT is elsewhere?
 

 

[Sharpend]

This highlights the deficiencies that are rife amongst many of the electrical 'firms'. Either you are electricians or not, if you want to portray yourself as such the least you can do is turn up with the correct test equipment to ensure what YOU do is satisfactory never mind checking what anyone else may have done before you. 

How is it that these type of firms have one or two or more teams of installers yet only one or two testers, when technically the person who's testing if different to the installer can issue no more than eicr? However I'm pretty sure, no I know that each install has an eic for the job-so how does that happen? 

I'd love for someone who is either undertaking business in this fashion or their representative body to come on here and explain. 

Oh and I don't believe the testing person sees each and every job at all stages of install either. 

 

[kerching]

I thought companies had to,have 'sufficient test equipment for the number of employees" or words to,that effect

or does he mean HUMAN testers and not test EQUIPMENT?

 

[Andy™]

It's not my test kit and have other staff would be silly to have 20 testers don't you think ? 

do you have to share screwdrivers too?

 

[Sharpend]

do you have to share screwdrivers too?

Now you're being silly, Aldi and lidl  have regular offers on screwdrivers! 

 

[ProDave]

Now you're being silly, Aldi and lidl  have regular offers on NEON screwdrivers!

Corrected that for you. Dead testing taken care of :innocent
 

 

[Chewbacca]

Enough of the character assassination by speculation. You have no-idea what Doctors circumstances are 

 

[SLIPSHOD & SLAPDASH]

Although is preferable to use double pole  Rcd protection on a TT supply BS7671 does not state you have to, only double pole isolation.

 

[Tony S]

Although is preferable to use double pole  Rcd protection on a TT supply BS7671 does not state you have to, only double pole isolation.

Hopefully something that will change with the 18th

 

[steptoe]

Although is preferable to use double pole  Rcd protection on a TT supply BS7671 does not state you have to, only double pole isolation.

but surely it must be isolated under fault conditions?