300mA RCCD failed at x5

[Paultrim]

Quick one, test was carried out earlier on a 300mA RCCD at x1 times (satisfactory) and x5 times - out of range.

I know that the regs don't ask for x5 for 300mA but should this be noted as a Cat 2 defect or 3 for observations?

 

[Technician]

I was informed that only 30mA RCD's should be tested at

times 5. The fault current at 300mA times 5 would be too

high. I may have seen this in an NIC guide.

 

[Paultrim]

Correction; the device did not trip at all at x5, my engineer has just confirmed

 

[steptoe]

Whatpurpose is there in doing X5 on a 300mA RCD?

Do you realise how much current you are trying to test at? Does your tester even do this test?

 

[Paultrim]

It was actually carried out by mistake as he had just tested a 30mA RCBO and had left the RCD tester set at x5 times and had changed it to 300mA and carried out the test on the RCD. It was more an observation and now where curious as to whether to report it as a Cat 2 or C3

 

[m4tty]

Only 30mA rcd's need to be tested at 5x.

 

[steptoe]

Why? Is the question.

This is one of the things that annoys me, people blindly testing and wanting to code but not knowing why.

 

[Paultrim]

Yes I already know 300mA don't need testing thanks as I said in my first post.

 

[oscar.maskell]

This is what I was trying to get at silly comments bit genuine answers

 

[Paultrim]

Gents I already have stated a couple of times that I understand that 300mA RCD's do not need testing at X5. It was tested by mistake as he had just tested a 30mA RCBO and had left the meter set at x5 for a 300mA!

Pure accidental test, but has raised a question of why in the regs does it state max disconnection time for a 300mA x5 (1500mA) of 40m/s and

I KNOW it is not a required test but the engineer has observed it did not trip.

 

[m4tty]

I know where your coming from mate. I think rcd's only need testing at 5x for additional protection so that's 30mA only I believe but stand to be corrected. Testing a 30mA at 5 times is 150mA don't think it would be safe to test at 5x 300mA

 

[Jono Pashley]

If it makes you feel any better just bin it and replace it for your peace of mind, although if its tripping at x1 id be inclined to question weather the tester can perform x5 on 300mA and the lack of a reading is a result of the tester throwing a fit. If it trips at x1 leave it unless you can prove it isnt the tester causing issues.

 

[Technician]

Gents; I put a post on this and I referred to an NIC

guide. I have run this past a couple of colleagues &

found the guide.

I quote; "If the RCD is not required to provide additional

protection (30mA) the test (times 5) is not essential &,

if not undertaken insert N/A in the box".

I hope this clears the matter up but I have run into this

before, and have had a few animated conversations on

the matter.

The source is the NIC guide (17th edition) and while some

might question whether it is updated to the amended version

I think this should suffice.

HTH.

 

[sparkytim]

In answer to your actual question the test Meter probablly did NOT do the 5x Test at 300 m A hence NO trip.

 

[Paultrim]

Cheers for the advice all, it created a few good discussions in the workplace too.

 

[Sidewinder]

Did the tester actually test the RCD at 1.5A?

It could be that the reason it did not trip is because the tester (testing machine, not testing person) did not apply the correct current.

I was not aware of many if any testers on the market that are capable of testing an RCD at 1.5A test current (i.e. 5 x 300mA = 5 x 0.3 A = 1.5A).

IIRC mind does a max of 1A and I "thought" that that was the highest on the market.

 

[Doc Hudson]

but has raised a question of why in the regs does it state max disconnection time for a 300mA x5 (1500mA) of 40m/s and I KNOW it is not a required test but the engineer has observed it did not trip.

I think you will find the regs do not state a x5 disconnection time for a 300ma RCD. Regulation 415.1.1 clearly states an RCD rating not exceeding 30ma rating to be tested at x5. As such your question could be similar in concept to someone trying to get a low enough Zs reading on a TT installation and asking what code do I give a high Zs on this TT inspection. Wrong test, Not applicable in the situation described therefore has absolutely no consideration for any coding. Any person competent enough to undertake testing of an installation would be clear of the fundamental requirements of the correct test procedures and the expected acceptable results. These sort of questions do indicate a tester working outside of their scope and abilities as such they would be better working along side a competent person until their experience develops to a satisfactory level to work alone.

Doc H..

---------- Post Auto-Merged at 23:46 ---------- Previous post was made at 23:35 ----------

This is what I was trying to get at silly comments bit genuine answers

If you were genuinely concerned about how the forum runs and respect for other members you would do well to stop hi-jacking other peoples threads with your personal gripes. Unless it is just your personal ego trip?

Doc H.

 

[batty]

Not sure what tester you have but even my old cheap ones won't do that test as A its not needed and B it could be dangerous.

 

[Doc Hudson]

Not sure what tester you have but even my old cheap ones won't do that test as A its not needed and B it could be dangerous.

Do many testers do a 100ma @ x5? 0.5Amp flowing down the CPC is not good IMHO.

Doc H.