220V and 380V electrical equipment

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JamieP
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220V and 380V electrical equipment

Post by JamieP »

I've come across a number of items of equipment lately that is rated for 220V single phase and 380V three phase

Although close, am I correct in saying because they are below our nominal voltage supply that they aren't suitable to be supplied as standard?

Curious what the best option is if the client wants to go a head with install anyway, install an isolating transformer? Just curious how others normally approach this
AlecK
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Re: 220V and 380V electrical equipment

Post by AlecK »

Energy Safety regard such appliance / fittings as electrically unsafe.
The marked voltage rating have to either state '230 V" or a range that includes 230 V.
I'm sure this will be on Worksafe website somewhere - but may be hard to find.

They also recently explained that RCDs marked '240 V" were not necessarily OK for use in NZ
and that they certainly won't have an Approval as DHRAs

However ESR 23(1)(a) doesn't state this specifically.
JamieP
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Re: 220V and 380V electrical equipment

Post by JamieP »

Interesting, I have just seen another comment in regards to this recently

Is this something that has been gazetted? If it's not specifically in Regulations how do such requirements and limitations hold up in the way of enforcement or is it just a case of it's not wise to go against those above you when there is fair logic to back it
AlecK
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Re: 220V and 380V electrical equipment

Post by AlecK »

Good question.
Not the only area where what ES say, and what they've put into ESRs, are not fully aligned.

In the end it's down to individual electrical worker as to whether they are prepared to connect something
- bearing in mind the fact of having connected it goes on the record via ESC.
JamieP
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Re: 220V and 380V electrical equipment

Post by JamieP »

I recently made a post in regards to solutions to supplying equipment that had a 380V motor and 220V solanoids. Clearly to me this was designed for a 220/380 supply system, was still all 50Hz

My thoughts was I would either need to replace/rewire or get an step down transformer but I was met with basically every response saying there was no need and it will be fine

Maybe it will be fine, and maybe it'll run with no issues, I'm not saying it won't but the real question is is it compliant? I don't believe it is but how can this be backed up? I can't find any reference to the above WorkSafe/EnergySafe information

I see 2.2.4.2 but is this enough to back up myself? The 220/380 does fall within our supply tolerances as many people mentioned but this also means it could be supplied at +6% of 230/400 which is up too 243.8V or 424V, that's 23.8V +10.8% or 44V +11.6% higher than what it's apparently rated for judging my the name plate
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DougP
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Re: 220V and 380V electrical equipment

Post by DougP »

AlecK wrote:
Mon Dec 13, 2021 11:08 am
Energy Safety regard such appliance / fittings as electrically unsafe.
The marked voltage rating have to either state '230 V" or a range that includes 230 V.
I'm sure this will be on Worksafe website somewhere - but may be hard to find.

They also recently explained that RCDs marked '240 V" were not necessarily OK for use in NZ
and that they certainly won't have an Approval as DHRAs

However ESR 23(1)(a) doesn't state this specifically.
I haven't seen anything specific, but were they talking about domestic only? Or non-domestic as well?
And as you say, ESR23 doesn't have the same wording regarding the range of supply voltage for equipment.

Obviously equipment doesn't explode if the voltage is 5% over, and the equipment tolerances are just as much related to power dissipated, rather than just the supply voltage. How much will the power actually increase at the higher voltage?
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Re: 220V and 380V electrical equipment

Post by pluto »

The problem now is the appliance series of standards as/nzs 60335 allows for a +/- 10 % window ( 253 V to 207 V) for the nominal 230 V supply so the max voltage range has now become much wider. Remember most supply companies usually use 240 V is the target so that at max loading periods they are still delivering a nominal 230 V supply.

An older appliance or a 220 V nominal appliamce will be hard pressed to continuously operate safely at 253 V.
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