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: Heat pump isolators

scottie
Aug 07 2016 12:00

Are isolators for heat pumps allowed to be mounted on the external unit itself. I know there has been previous discussion about this but it is still a bit up in the air. I never mount them on the unit because if you have to ever remove the unit for any reason it's a lot more work. I have noticed a lot of installers in my area are.
   

DougP
Aug 07 2016 12:19

This is going to be clarified in the next release of NZS3000 where 4.19 will be changed from:

Airconditioning and heat pump systems incorporating a compressor shall be
provided with a lockable isolating switch installed adjacent to the unit,
which isolates all parts of the system including ancillary equipment, from
the same location.

---------
To:
Airconditioning and heat pump systems incorporating a compressor shall be provided with a lockable isolating
switch installed adjacent to but not on the unit, which isolates all parts of the system including ancillary equipment,
from the same location.
   

BrianW
Aug 07 2016 15:21

and in the meantime be happy in the knowledge that it's appalingly bad practice and in most cases voids the manufacturers warranty. Believe it or not the don't actually want bloody great holes bored in their cabinets, and things screwed to it, that could lead to premature rusting.
   

DougP
Aug 07 2016 17:32

Personally, I thought "adjacent to" was pretty clear. You only need to check a dictionary for "adjacent" to get your answer.
   

Sarmajor
Aug 07 2016 20:07

I'm with Doug on this. Adjacent means not on the unit itself.
Pretty hard to isolate the unit for removal / replacement if the feed cable runs through it.

I see a lot of units fitted with the PDL WS switches which do not meet the requirements for an Isolator as per AS/NZS30002007 section 2.3.2.2.1.
   

AlecK
Aug 08 2016 08:20

Nor does the 56 series 10A - uses the same micro-gap switch mech.


   

DougP
Aug 08 2016 10:21

Yes Sarmajor there are plenty of installations that don't comply with the new wording, or with the definition of an isolator.

But 4.19 was only added with A2, so previously (and I stand to be corrected here), they came under possibly a mixture of "room heaters" and "motors".
   

DougP
Aug 08 2016 10:23

In any case, the "devices for isolation" requirements seemed to have been largely ignored up until 4.19 was added with A2, as long as the "switch" was lockable. PDL key operated switches were popular down this way.
   

dbuckley
Aug 08 2016 23:23

> Airconditioning and heat pump systems incorporating a compressor shall be
> provided with a lockable isolating switch installed adjacent to but not on the unit,

So its OK to continue to mount isolators on air handling metalwork that doesn't incorporate a compressor....?
   

pluto
Aug 08 2016 23:30

dbuckley Aug 08 2016 23:23
Your comment
> Airconditioning and heat pump systems incorporating a compressor shall be
> provided with a lockable isolating switch installed adjacent to but not on the unit,

So its OK to continue to mount isolators on air handling metalwork that doesn't incorporate a compressor....?

My comment

If the air handling metalwork would remain during a compressor changeover the answer may be YES.

if the metal work needs to removed in order to change the compressor unit the answer is NO.
   

johnsmith
Aug 31 2016 17:01

It is essential to have unimpeded air flow around the coil. The gap from the outdoor unit to any obstruction needs to be at least 500 mm on the air inlet and outlet faces, and 100 mm on any other face.

In my opinion, heat pumps should be installed by experienced professionals. So, you should contact expert near you.



Water Heating Repairs



   

SaintAlan
Aug 31 2016 17:37

I have used the PDL 56 series switched socket outlets for AC units, and a short flex to the unit. Makes removal and maintenance easy.

I take it these are still allowed, with the new isolation requirements covered by having a removable plug?
   

AlecK
Aug 31 2016 19:46

Would be OK if 16 A or better.
The requirement is an "isolating switch", and the 10 A mechs don't comply
   

mf51to1
Jun 08 2017 21:20

Came across this today...a reputable(?) AC company saying to me its ok to mount the isolator onto the AC unit itself. They even knew it was in the 3000 but said "everyone is doing it so its ok".
I don't ever really see it installed that way, but anyway...
So one unit I connected (and mounted the isolator next to the unit and I had to extend the supply cable). The other unit was getting replaced and the AC company connected it, of course they mounted the isolator on the new unit, didn't have the circuit locked out, and NO TESTING.
   

Sarmajor
Jun 09 2017 00:03

Bring back full inspection until the Cowboys get the message and leave.
   

zl2aj
Jun 09 2017 07:52

Make a complaint

https://www.ewrb.govt.nz/assets/subsite-ewrb/Documents/forms/4.1-lodging-a-complaint-against-a-person-carrying-out-electical-work.pdf


   

AlecK
Jun 09 2017 08:40

Not supporting the attitudes described, but if the second unit was a replacement of an existing one that had no isolator, then a complaint may not succeed. Depends how the EWRB interpret things, and history is less than encouraging on that.

If installing (or relocating)a heat pump, the isolating switch is required, so must be adjacent to but not on the unit.

If replacing, switch already "on unit" (as used to be allowed); ESR 59(3)(b) allows switch to be re-located onto new unit.

If replacing unit with no switch; same ESR says replacement can still have no switch.
Can choose to add a switch - and common sense says installing switch for heat pump should follow the heat pump rule. But there's precedent for sometimes not following rules. RCDs that are required must comply with ESR 24. RCDs that are fitted voluntarily don't have to comply. Following that logic, maybe installing a switch that isn't required also doesn't have to comply?

I believe same ESR prevents adding switch on-unit; as not "original condition". So could come down to whether the investigator knows enough to cite the right rule.