I'm totally baffled !!??

[goasis]

And all the circuit Zs readings are waaay below Ze value ?! Were these measured with all the bonding connected ?

That's to be expected though isn't it?

 

[littlespark]

The tester apparently didn't even know what voltage he/she was doing the IR testing at, or any mention of how they've managed to get RCD test results when there's no RCD mentioned, and presumably don't know where to find max zs values in bs7671 as they are N/A as well.

I had to look at that… the BS number suggests MCB, but there’s RCD trip times. Wasn’t until I noticed the times were all the same that I realised.
Must be a dual rcd board,

 

[goasis]

I had to look at that… the BS number suggests MCB, but there’s RCD trip times. Wasn’t until I noticed the times were all the same that I realised.
Must be a dual rcd board,

So why aren't they listed at the top of the certificate then? The cert is a load of crap.

I think I over worry about getting things wrong/ missing something and look back at some things I've done or not understood correctly in the past and cringe, but then you see something like this, this is just poor.

 

[timhoward]

So why aren't they listed at the top of the certificate then?

I certainly would do this for clarity, and I know what you mean, but is there an absolute requirement to list the two RCD's on their own line?
Ultimately we are listing final circuits and what is protecting each one.

 

[goasis]

I certainly would do this for clarity, and I know what you mean, but is there an absolute requirement to list the two RCD's on their own line?
Ultimately we are listing final circuits and what is protecting each one.

I was thinking the " characteristics of this db" section, "associated RCD's". Would you not use that?

 

[timhoward]

I was thinking the " characteristics of this db" section, "associated RCD's". Would you not use that?

No, as that is "Complete only if not connected directly to the origin", i.e. a sub main
Napit's certifcates could be better worded in that part.

 

[goasis]

No, as that is "Complete only if not connected directly to the origin", i.e. a sub main
Napit's certifcates could be better worded in that part.

Oh yeah, see that now. Good point.

 

[littlespark]

There’s enough lines to add in a couple of rcd’s.
That gives a chance to note their BS numbers, size etc… which could be wrong when you total the load that it’s expected to carry.
N/A or leave blank a lot of the other columns, but put “for circuits 1-5” or whatever it is.
Looks understandable when you’ve got the sheet, and the board in front of you.

Just lazy not to

 

[telectrix]

Normally, there is no voltage neutral to earth… so it’s possibly not an option on these testers.

Looks like VIR tails between cutout and meter which could do with being replaced, but that should be done if the meter is changed.

The test certificate doesn’t have a number for “points served”
How difficult is it to count light bulbs?

all depends on how deep you planted them.

 

[Deleted account]

Split board on a TT system. I hope there is an up front time delayed RCD.

@Torturedsole , any chance of photo of CU with lid up.

 

[Dave OCD]

That's to be expected though isn't it?

I must be having a thick moment ?! Thought Zs was Ze + R1&R2 ?

 

[goasis]

I must be having a thick moment ?! Thought Zs was Ze + R1&R2 ?

Interesting, by calculation yes, but would you take a Zs measurement without bonding connected?

 

[Julie.]

The tester apparently didn't even know what voltage he/she was doing the IR testing at, or any mention of how they've managed to get RCD test results when there's no RCD mentioned, and presumably don't know where to find max zs values in bs7671 as they are N/A as well.

Zs isn't really applicable with a TT system as the RCD is providing fault protection, not the mcbs - they would never trip with 315 ohm earth rod.

 

[goasis]

Zs isn't really applicable with a TT system as the RCD is providing fault protection, not the mcbs - they would never trip with 315 ohm earth rod.

Yeah I know... maybe I was over reacting. No excuse for the NA in the IR test voltage tho eh?!!

 

[Julie.]

Yeah I know... maybe I was over reacting. No excuse for the NA in the IR test voltage tho eh?!!

Nope, pure muppetry that one!

 

[Torturedsole]

Yea i can take a photo of the cb.

But we have seemed to of gone wayyyyy off topic here

 

[Julie.]

OK, let's try to explain.

A socket tester basically measures three voltages simultaneously.

The first (LH) green LED indicates that there is some voltage between line and neutral - which there should be in correct operation.

The second (Centre) green LED indicates that there is some voltage between line and earth - which there should be in correct operation.

The third (RH) RED LED indicates that there is some voltage between neutral and earth - which normally there should NOT be in correct operation (at least not too much voltage).

How much voltage? - well that depends on the tester, some containing electronics will indicate at lower voltages than less fancy ones, but typically it may be 50v

So the tester is basically saying there is at least 50v (ish) between L - N -- OK, L - E -- OK, and N - E -- NOT OK.

why are you getting a reasonable level of voltage between N & E - Well that's not too unrealistic with a TT system, the neutral and earth can differ by some amount, these quick testers are not great on TT systems, some are OK as they may trigger at 50v, which would indicate a genuine issue, others may operate at a much lower voltage.

You need firstly to measure the voltage L - E using a high impedance meter (like a multimeter), then via a lower impedance meter such as a MFT (multi function tester), you would need to bring in a proper electrician for this.

Does this actually represent a danger - well it depends on the results - if the voltage measures the same, then you have a genuine voltage, and depending upon the value it is OK, or not.

If the voltage changes between the two measurements, then you have a poor/missing connection, likely in the CPC (earth) which is an issue.

Edit:

Should really have added, that some of the more fancy socket testers actually try to measure the Zs and if greater than a certain value ( typically 1.5 or 2.5 ohm) then the electronics flags it as a fault, and since your Zs are around 315 ohm (TT) then a fancy one would do this.

 

[Julie.]

Also, and not relating to the "issue" , that tester you are using has been recalled for safety issues.

If you contact fluke they will replace it.

Fluke SM100, SM200 and SM300 Electrical Socket Testers Voluntary Recall

Fluke Corporation has identified a safety issue concerning the Fluke SM100, SM200 and SM300 Electrical Socket Testers. As a precautionary measure, Fluke has decided to voluntarily recall all of these products and provide affected customers with free replacement products.

www.fluke.com

 

[nicebutdim]

Also, and not relating to the "issue" , that tester you are using has been recalled for safety issues.

If you contact fluke they will replace it.

Fluke SM100, SM200 and SM300 Electrical Socket Testers Voluntary Recall

Fluke Corporation has identified a safety issue concerning the Fluke SM100, SM200 and SM300 Electrical Socket Testers. As a precautionary measure, Fluke has decided to voluntarily recall all of these products and provide affected customers with free replacement products.

www.fluke.com

They won't directly replace it, but will send a T90 voltage tester.

 

[Julie.]

They won't directly replace it, but will send a T90 voltage tester.

Yeah, there are a couple of options, neither are that good tbh

The issue is really esoteric, basically if the only connection is one 230v live (neutral or line), then you could get circ 10mA if you touched the earth (when the cpc is missing), so I would be happy to use them in any case.

In saying that, I don't have a socket tester, I fid my mft is perfectly capable of testing socket outlets.