Splitting Load. Is it safe?

[telectrix]

Micro brewery... Brewing Vat has 2 elements, 9kW and 6kW. Done the calcs and each element will be fed with 6.0mm XLPE. no problem.My query is would it be safe and compliant to split the 2 elements across 2 phases in order to balance better. Can't see a reg.preventing this, but something nags about having 415V PD in what is essentially a single appliance.

 

[Midwest]

Dunno, but you can have 415V at a light switch.

 

[Intoelectrics]

I've done work on commercial kilns in the past and the elements are single phase. But there is usually a bank of elements, so they are split across the 3 phases to balance the loading. So potentially you have 415V PD within the kilns, I can't see how this scenario (in terms of install) is any different than yours. So long as it is clearly marked up with the correct warning signs and both phases isolate simultaneously.

 

[littlespark]

Any 3 phase appliance has 415v PD. It doesn’t need anything extra in the way of insulation or protection than if they were 230.

If you get it done by Xmas do you get paid in brew?

There’s a joke somewhere about Tel organising a p**s up in a brewery... I’m sure it’ll be along any time now

 

[Intoelectrics]

Any 3 phase appliance has 415v PD. It doesn’t need anything extra in the way of insulation or protection than if they were 230.

The way I read it was that its a single phase appliance that Tel wants to split over 2 phases.?

 

[Wilko]

If the internal cables are rated then I think it's fine. Plenty of domestic hobs are 3 phase from factory.

 

[Spoon]

I presume it will be wired back to a 3 phase board with a 2 pole breaker, so I can't see a problem. Put a 415v sticker on the micro brewery.

 

[westward10]

No problem whatsoever, warning notices or double-pole protective devices not required.

 

[telectrix]

each element is single phase, with a 6.0mm flex. each will have it's own local isolator fed from a single phase 50A MCB. ( fixed load so overcurrent protection not necessary) so there's no way of isolating them simultaneously. the way the customer explained, he needs to have either one or both in use at any one time. from the posts so far, it appears that you all agree it's OK, but introelectrics has suggested simultaneous isolation. bit unsure about that.

 

[Intoelectrics]

each element is single phase, with a 6.0mm flex. each will have it's own local isolator fed from a single phase 50A MCB. ( fixed load so overcurrent protection not necessary) so there's no way of isolating them simultaneously. the way the customer explained, he needs to have either one or both in use at any one time. from the posts so far, it appears that you all agree it's OK, but introelectrics has suggested simultaneous isolation. bit unsure about that.

No problem so long as its marked up. The kilns I refer to are installed in such a way that its fully isolated when the doors are opened. My thinking being that a 3 phase rotary isolator installed at some point to isolate both supplies simultaneously would be good practice, should it be required?

 

[telectrix]

both isolators will, be adjacent to each other and can be isolated simultaneously albeit he'll need to turn both off manually at the same time.

 

[MFS Electrical]

Don’t really know about current regs on the matter but I used to work on 3phase calorifiers where each element had its own phase. I reckon as long as the OCPD is interlocked and the manufacturer permits it then it should be ok

 

[richy3333]

Hope it’s ok as I recently did something similar

 

[westward10]

Unless there is a safety issue there is no need for linked circuit protection.

 

[telectrix]

Don’t really know about current regs on the matter but I used to work on 3phase calorifiers where each element had its own phase. I reckon as long as the OCPD is interlocked and the manufacturer permits it then it should be ok

deflated
not a typo, just tired of seeing the word deleted.

 

[magnoliafan89]

Hey guys piggy backing off another topic....again...totally irrelevant to topic but it made me think of it
I was once told that if you had for arguements sake a socket on l1 and another on l2 they had to be a certain distance apart (i have 2m for some reason) is this a reg or just best practice? I was told the reasoning was is that if u had to points on two circuits fed by differenr phases you want them so far apart other wise you could potentially have someone get 400v if they had contacr between the both?

 

[westward10]

Hey guys piggy backing off another topic....again...totally irrelevant to topic but it made me think of it
I was once told that if you had for arguements sake a socket on l1 and another on l2 they had to be a certain distance apart (i have 2m for some reason) is this a reg or just best practice? I was told the reasoning was is that if u had to points on two circuits fed by differenr phases you want them so far apart other wise you could potentially have someone get 400v if they had contacr between the both?

Up until the 2011 amendment to the 17th Ed there was a requirement to put notices in place where voltages between separate enclosures, which were simultaneously accessible exceeded 230v, this is no longer the case. Trying to keep voltages at 230v between enclosures has never been a requirement more a case of good practice which many people still believe today, it has never applied and still does not.
If you have pre and post copies to 2011 see Regulation 514.10.1

 

[Toneyz]

Micro brewery... Brewing Vat has 2 elements, 9kW and 6kW. Done the calcs and each element will be fed with 6.0mm XLPE. no problem.My query is would it be safe and compliant to split the 2 elements across 2 phases in order to balance better. Can't see a reg.preventing this, but something nags about having 415V PD in what is essentially a single appliance.

You getting ready for Christmas then Tel, by the looks of it.

 

[telectrix]

You getting ready for Christmas then Tel, by the looks of it.

unfortunatelyit takes several weeks for the brews to ferment etc., so enen if i got them up and running before xmas, the first drinkable ales would be February/March. in time for easter though.