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Posted By Topic: Gas fires - isolating switch

bakinthegame
May 23 2017 17:37

Have just begun installing gas fires for a distributor.
From my previous understanding I was under the impression just a standard 600 series switch was ok - from my reading of 2.3.2.1.1 this would appear to be correct but the 2.3.2 section is quite confusing to say the least.
Interested in others opinions as I'll be doing a few of them & just want to make sure I've got my own backside covered.
   

AlecK
May 23 2017 17:56

You're in the wrong place.

Try 4.18.1 Gas Appliances.
There must be a means of isolation; and it must be one of the 3 options given.

Note also that this clause has been modified by citation in Schedule 2 of ESRs, so that there is no need to switch the N in NZ (if using a switch as the means of isolation)

Also, if using a switch as a means of isolation, it must of course be an isolation switch (this fact is being spelled out in next edition).

Nothing in the 600 series - nor any similar range - is an isolating switch (ie meets the requirements of clause 2.3.2.2)
In 56 series, you'll need to go up to min 16 A rating to find an isolating switch; as the 10 A ones use the same mech as 500 & 600 series.

Same applies to the WP series, so there are plenty of heat pumps with non-compliant switches.

Next edition will also require isolating switches for water heaters; the current common practice of a PCU will become non-compliant.

For all three: gas appliances, heat pumps, and water heaters; the reason is because non-electrical people can be expected to have to work on them, so require isolation adjacent.

And in the same way, switching the lights - or whatever - off at the wall while you work on them isn't good enough, because - again - standard wall switches are not isolating switches so can't be used to isolate for safe working.
   

bakinthegame
May 23 2017 20:04

Thanks Aleck for the detailed response.

Obviously easiest way go is an adjacent switched socket.
Funny because every gas fire ive seen to date including new homes - sparkles have just used a 600 series switch or similar.
Also cancels out a socket under the house which apparently the previous installer was doing as its not adjacent.

Good that the fact the switch needs to be an isolation switch & not a functional switch is getting spelled out in the next edition - as at the moment you could get them on a technicality!

They are certainly making what should be a very simple job very complicated though.
The problem i have with this reg is a repairer could leave the unit plugged in & just flick the socket switch into the off position.
What is the difference between this and using an accesible functional switch to switch an inaccessible socket on/off??
It's not clear that you need to not switch the neutral in NZ either as there is no reference to schedule 2 of ESR in the wiring rules but I'll take your word on that one.
Often with these installs the socket really does need to be in an inaccesible position & out of sight as no-one wants to look at there brand new $10K fireplace plugged into a socket.
Which brings back to the next solution which is an isolation switch. No customer is going to want to be staring at an unsightly 56 series switch in their lounge.
This reg is not easily applied to everyday use & with the products on the market there really needs to be an exemption - honestly this should be an easy quick job & the amount of red tape around this its totally ridiculous.
In practice its making it very hard to comply!
FRUSTRATED!!!
   

Sarmajor
May 23 2017 21:29

Schedule 2 is part of the Electrical (Safety) Rules 2010.
It is not in AS/NZS3000:2007 (The Wiring Rules) because the ESR's overrule and can modify the requirements of parts of standards.

Have a look in the back section of the ESR's around page 127.
   

bakinthegame
May 24 2017 08:53

Thanks I've read the amendments & it's right that the neutral doesn't need to be switched - but an 'isolating switch' is still required which doesn't solve any of my practicality issues which I've mentioned above.
   

AlecK
May 24 2017 08:56

It's not an issue for hobs - generally a socket in the cabinet below is the way to go.
Similarly not an issue for califonts ("infinity" & similar gas water heaters), as looks generally not an issue if locatedin service area.
But yes, a definite problem for gas fires, where either a socket / plug / flex or an industrial type isolating switch could spoil the "look".

The rule comes from gas installation Standard, carried across to 3000. NZ is fighting back re N-switching; but Oz seems happy to let gas people write electrical rules.

You're right that a gas service person might not bother unplugging - a matter for training I guess; We know most electricians don't bother to isolate correctly either. The difference between switching off the socket without unplugging, and switching at a remote switch for a hidden socket; is that the remote switch has to be an isolating switch.

Though you're right that currently many aren't; and the current wording doesn't make it clear enough (especially when the reader doesn't want to comply with what he really knows is meant).

Might help to have the definition for "Adjacent", in new edition:
Next to or adjoining without obstruction and in any case within arm's reach

Seems there's nothing available that looks nice. Given the small size, chances of a true isolating switch becoming available in any of the "domestic" ranges of wallplates is tiny; especially given it's for such a small market. My understanding is that , for 600 series, the 32 A mechs have a suitable contact gap for isolation (though would need to be confirmed by testing)- but they aren't lockable. And in Oz, it would need to be double pole.
   

bakinthegame
May 24 2017 17:37

It's a ridiculous scenario that is causing people to knowingly break the
Who knows maybe a 56Series Industrial plug will come in to fashion to have next to your fireplace in Remuera.

My point with the 600 series functional switch switching an inaccessible socket is that its exactly the same as having a plug & switch socket which is allowed.

The rules need to be looked at in this area - as its a ridiculous scenario which is causing people to knowingly break the rules as its absolutely unpractical.

I will have to Turn away the business of installing them as I'm forced to break the rules otherwise.

I still cant see why on the odd occasion they need to be repaired why a repairer cant turn off the mains for isolation or rules could be changed so that at least a double pole mech would suffice instead of An 'isolator'.

A simple job shrouded in red tape to render a reasonable solution impossible.

RIDICULOUS

Vent done...guess I'm just going to have to lose what could have been a profitable part of my business.



   

AlecK
May 24 2017 18:20

"My point with the 600 series functional switch switching an inaccessible socket is that its exactly the same as having a plug & switch socket which is allowed."

No, it's not.
Point being you can get true isolation by unplugging (including the N for Oz).

Agree it's a pain due to lack of suitable switch
But doesn't matter what we have in "3000", 'cos the gas rules require the same 3 options, so one way or the other we need to do it.
That's why we included it into "3000", 'cos that's where most sparkies will be looking. Not many will buy the gas installation Standard. So they'd do their thing; then be told by the gas fitter 'I can't use that".
   

bakinthegame
May 24 2017 18:43

"My point with the 600 series functional switch switching an inaccessible socket is that its exactly the same as having a plug & switch socket which is allowed."

"No, it's not.
Point being you can get true isolation by unplugging (including the N for Oz)."

It is if the repairer chooses not to unplug the appliance & just flicks the switch on the socket instead.
Which means that even the actual regs aren't foolproof so what's the point? And a double pole switch should be good enough anyway - how many lives do they think their going to save by insisting it must be an isolator?

To quote a crappy NZ Rapper - "not many if any"



And no-one is adhering to this particular rule anyway (at least in a gas fireplace situation) because they simply don't work in real life.


   

AlecK
May 24 2017 19:49

Not isolating is stupid.
Where other trades may be working on equipment, it makes sense to mandate a means of isolation that is handy & obvious. Relying on them finding the switchboard, and on the sparky having fully labelled (when after all he doesn't have to) doesn't make sense.

Also stupid is putting appearance before safety. However a bit of lateral thinking solves most conflicts between the two.

Genius may be limited, but there are no limits to stupid. Which is why it's impossible to make rules fool-proof - best that can be done is make them adequate for those who take care.


   

pluto
May 24 2017 19:54

Another way to look at the lack of suitable impulse voltage capable isolators, if no one asks the fitting manufacturers to make one, they will never ever be made.

What is done in the UK and in Europe is they have "isolating switches for mechanical maintenance" in which no electric wiring conductors are being touched. These switches have the performance of a function or control switch.

They also have "isolating switches with impulse voltage rating" for when wiring is normally alive is being worked on and touching the bare conductor with the isolating switch is in the off position.

For example, those controlling a water heater when live conductors are worked on when the W/H element is being replaced. This has the same preformance of a main switch or protective device like an MCB or RCD.

The international term for this class of work "hazardous-Live"

I have made a already made a submission to get this approach used in AS/NZS 3000:2017 amendment No. 1, so it is some 18 months away, but the submission has been made to get correct types of isolating switch used in the right places.
   

bakinthegame
May 25 2017 06:51

Again...no-one is doing it.

If we must use an isolator, if a double pole switch is deemed not good enough, then why can't we make an exception & have the isolator not adjacent but on the outside of the house?

Problem solved & everyone is happy & the repairer will know because it's in the rules - to look for the labelled isolating switch on the outside of the house.

Or heck ever heard of turning off a main switch instead.

Easy, safe solution - sometimes we have to meet each other halfway to get the right result.


   

AlecK
May 25 2017 07:24

You don't have to convince me, it's a matter of convincing the gas people. Until we can get then to accept the electrical rules should be written by electrical people, best we can do is ensure that our Standard doesn't say something different from what their Standard says.

Having tried that a couple of times so far; my guess is it'll be easier to get PDL, HPM, etc to make us a special isolating switch that's
a) tidy enough for the lounge / kitchen; and
b) waterproof for those special locations; and
c) double pole for Oz
   

pluto
May 25 2017 09:20

bakinthegame May 25 2017 06:51


Your comment 1
Again...no-one is doing it.

If we must use an isolator, if a double pole switch is deemed not good enough, then why can't we make an exception & have the isolator not adjacent but on the outside of the house?

Problem solved & everyone is happy & the repairer will know because it's in the rules - to look for the labelled isolating switch on the outside of the house.

Or heck ever heard of turning off a main switch instead.

Easy, safe solution - sometimes we have to meet each other halfway to get the right result.

My comment 1
provided the final sub circuit protection is a MCB or RCD you already have an impulse rated isolator and you don't need to use the main switch.

For electrical workers, a control switch by the gas heater and a true isolator on the switchboard is what can be done today and for older electrical installations.

For gas workers, with a associated trades electrical PL only, if they had to replace an electrically operated gas valve the local isolator is not good enough if you are touching conductors that would alive when yjr isolator is on.

However, the associated trades electrical PL should have been taught that the operation of the final sub circuit protection device if an MCB or RCD is also required to achieve full and correct isolation.

A purpose made true isolating switch adjacent to the gas heater would be the beast approach, then you don't need to find the correct MCB or RCD which is most likely to be poorly identified.

   

mowgli
May 25 2017 20:52

4.18 requires that the isolating switch must be "adjacent" and "accessible". 2.3.2.2 requires that it is "readily available". Neither requires that it has to be surface mounted or even visible.

Would it be compliant to mount the isolator in an adjacent, accessible and readily available cupboard or similar covered recess?
   

bakinthegame
May 25 2017 21:16

Pluto - my preferred option was to have the isolating switch placed on the outside of the house instead of adjacent - for some reason this website added on the comment of the main switch on the end when I thought it had been deleted.

I realise an MCB is adequate isolation but the main switch is just as good if not better (& easier) & then the muppet repairman who apparently can't tell if a cable is live or not doesn't have to try & find the right MCB for the gas fireplace - because the rules are obviously assuming that the guy is totally retarded.

Yes a cupboard/shelf/cabinet would be compliant - trouble is not everyone has one & many times your only faced with a bare gib wall
   

bakinthegame
May 25 2017 21:21

But hey nothing we can do - as Aleck & Pluto quite rightly point out we've been shafted by the Gas industry & most sparkies are installing these gas fireplaces illegally - knowingly or not
   

michael
May 25 2017 21:33

This is a big part of my biz also and if the rule makers havnt investigated the lack of appropriate isolator switches I will just continue with my functional adjacent switch ,mcb or RCD on switchboard and argue the point when challenged.If your going to make a rule have a practical and acceptable means to carry it out.
   

ppaw1965
May 25 2017 21:43

What you can do to make it look a bit more presentable is use a side entry plug and if there is some dark panelling/ wall use a dark brown/ black plug and outlet. Done the right way becomes less of an eyesore.
   

AlecK
May 25 2017 21:51

We currently have functional switches & isolating switches.
Many sparkies seem to have trouble with getting just these two types right. I'm not sure how having a third type would fly - without a lot of extra training, probably just more chance of it being wrong.

Similarly we currently only have one system of earthing, and many can't even get that right. Yet there's a plan to introduce TT earthing for some installations.
   

pluto
May 26 2017 22:10

I have already started the process off by my attempting to get the wiring rules up to date. ao it starts a process of creating a demand for the isolating switch with impulse rating doe fitting manufacturers.

Many years ago I was a person who made a demand for product for which no manufacturer at the time was making, by changing a Wiring Regulation change. With the need set the product required appeared in about 4 months.

I'm proposing the same process for an good looking isolating switch with an impulse rating for use in domestic installations for gas heaters and water heaters.
   

bakinthegame
May 27 2017 08:20

Amen.

Let's hope we can get a result!