Online assistance for electrical trade people Login  |  Register  |   Forgot Password
Assistance for electrical trade people
 

 

 

 


Click here to send Ron a pdf document for publication on this Topic

Documents must be less than 200k in pdf format

Posted By Topic: Portable Structures

Paul79
Feb 04 2018 16:48

Hi all,
I'm currently re-issuing W.O.E.F's...
Very old caravans with 1mm2 solid copper. Can I use the Grandfather clause to issue a W.O.E.F? or has it never been compliant?
I know it hasn't since 2001.

Thanks

   

pluto
Feb 04 2018 17:08

It is Ok to issue a WoEF for older caravans with 1 mm2 cable for lighting.

All caravans built to AS /NZS 3001:2001 after 2003 (approx) should have stranded cable, because that is when AS/NZS 3001 was first became cited by ESR 2010.
   

Paul79
Feb 04 2018 17:44

Thanks Pluto,

So if the caravan was built in 1975, (as a reference).

Does it need to comply with 3001.8 2008

Thanks
   

AlecK
Feb 04 2018 20:54

Of course not!

The requirements for issue of WoEF are set in ESR 78, citing that a WoEF must be issued i.a.w. "3001". The verification clause of that Standard (3.10) covers initial verification (3.10.1) & periodic reverification (3.10.2) . 3.10.2 is the relevant one, and states that WwoEFs must be issued i.a.w Appendix C. When you get to Appendix c, you find that the relevant clauses are C6 & C7.
For an NZ-built unit these 2 clauses are ALL that must be complied with.

Note a WoEF can only be issued by someone holding an "Inspector" PL . And anyone holding that should already know this stuff, or at least be able to follow it through from the ESR.

   

monty
Feb 04 2018 21:43

I had a look at a caravan the other day that had a type AC RCD. And it had a WOEF that had just ran out. Have the type AC RCDs ever been legal in Nz. Also had European sockets and mcbs Switching the neutrals of the final sub circuits
   

pluto
Feb 04 2018 22:53

monty Feb 04 2018 21:43

Your comment
I had a look at a caravan the other day that had a type AC RCD. And it had a WOEF that had just ran out. Have the type AC RCDs ever been legal in Nz. Also had European sockets and mcbs Switching the neutrals of the final sub circuits

My comment
Looks like a caravan built in the Europe (including UK to IEC 60364-7-721 rovisions.)

1. The RCD must be a 30 mA type A RCBO the amp rating of RCBO to be 16 A to protect the supply lead from overloading. Usually it is easy to chage over as both devices are the same size. Type AC RCD have never been able to be used for personal protection in NZ.

2. The socket outlet must be changed to AS/NZS 3112 types with a control switch (an auto switching type is not acceptable, there is a Energy Safety circular memo coming out about this new socket outlet switching requirement).

3. Double pole MCBs can remain, AS/NZS 3000 or AS/NZS 3001 does not prohibit their use provided that they are made as double pole devices.
   

AlecK
Feb 05 2018 09:46

To answer the specific question: NO, Type AC RCDs have never been acceptable for issue of a WoEF.

NZ-new units must have Type A as required by clause 3.3.2. Therefore App C does not need to, and doesn't, refer to the type of RCD [Accordingly C 6.10 simply requires RCD protection not exceeding 30 mA; while C7.2 requires the RCD to be tested i.a.w section 8 of "3000".


For imported units, it is part of the "Part 1 assessment". Clause 1.5.6.3 (e)requires RCD protection "as specified in" a selection of other Standards, including AS/NZS 3001. Thus a Type AC RCD cannot pass the assessment for compliance with Part 1.
It also won't pass the testing requirement of C4.2; because that involves doing a d.c. test on RCDs not marked as being intended to operate on residual pulsating direct current.

It follows that the previous WoEF for the one monty found was not issued validly.

---------------
Pkluto's responses are not strictly correct.

1
there is NO requirement that the RCD be an RCBO. That's usually the simplest way, but it is not a requirement. What makes it a good option is that it satisfies not only 1.5.6.3, but also C6.4 (overcurrenty protection of supply lead and fittings).

2a
It's true that the latest advice from Worksafe asserts that foreign sockets must be replaced with AS/NZS 3112 types. However that advice in incorrect, and is based on an incorrect interpretation of clause 1.7.3.
The claim is new, not having appeared in earlier advisory documents issued by Energy Safety.
That said, it is the official advice, so an inspector should only go against it if they are confident they could win a case.
There are also issues of practicability; since a foreign socket won't accept "3112" plugs used on NZ appliances, so should be changed.

2b
Also not true that the auto-switching sockets are not permitt4ed (and the Worksafe document doesn't say that). The facts here are that when / if a foreign socket is replaced then ESR 59(3) allows 3 methodologies for as "maintenance" of an installation. If the type of socket is changed, eg to a "3112" type, then option (b) "original condition" cannot apply; which leaves (c) "following MIs" and (a) "i.a.w. part 1 or Part 2 of 3000".
The Worksafe document cites clause 4.4.4 of "3000, and that clause specifically allows "auto-switch" types of socket.

3
The double-pole mcbs typically found in ex-UK caravans are unlikely to have the SDoC & Approval required for their sale or supply in NZ (including being sold / supplied as part of a caravan). However this is NOT part of an Inspector's responsibilites when inspecting 7 testing for issue of WoEF.
What does matter is that the subciruit conductors have acceptable overcurrent protection, so IF the type AC RCD has been replaced with a typE A RCBO rated 16A, then in pretty much every case the RCBO will provide overcurrent protection no6t only for the supply lead & associated fittings upstream; but also for the subcircuits downstream. The original 2-pole mcbs are therefore redundant except as connection & isolation devices.

Pluto is correct that neither 3000 nor 3001 prohibit switching of subcircuit neutrals, as long as the active(s) are switched simultaneously. In fact use of mcbs that switch neutral as well as active is desirable in some cases, as it allows complete isolation of the subcircuit - which makes tracing of earth faults easier.

---------------------
Unfortunately finding that previous WoEFs have been improperly issued is far from uncommon. Which may be part of why the "Part 1 assessment" for imported connectable installations must be done not only for the first WoEF, but for EVERY WoEF. However the faults I find are often not Part 1 issues, but App C issues; which indicates that a significant? number of inspectors are simply not competent, and can't even follow a basic checklist.