112 KVA

[websparky]

On a final inspection of a new restaurant last week I discovered a 150 KVA dry type transformer suspended above the suspended ceiling. I was supposed to find a 112 KVA. I asked the electrician and he guessed that the restaurant chain ran out of the 112 and substituted a 150. He wasn't aware of any code violation.
Has anyone ever seen a class 155 or higher and was it installed in this location?

 

[mdshunk]

Re: 112 KVA

Most of the one's bigger than 112-1/2 kva that I use are Class 180 or Class 220. Naturally, they are enclosed except for the vent opeings. Might be a real good idea to check out the data plate on the one that actually got installed there.

[ December 25, 2005, 10:55 PM: Message edited by: mdshunk ]

 

[pierre]

Re: 112 KVA

What about 450.13(B)?

 

[mdshunk]

Re: 112 KVA

Originally posted by pierre:
What about 450.13(B)?

I'm not sure that I understand that query. Are you saying that you believe 450.13(B) refers to the area above a drop ceiling as "hollow space"? Until someone defines that a little better, I say it's just the "area above a drop ceiling" and not a hollow space. Heck, a mechanical room is a "hollow space" if we lack a clear definition.

 

[iwire]

Re: 112 KVA

Originally posted by mdshunk:

Originally posted by pierre:
What about 450.13(B)?

I'm not sure that I understand that query. Are you saying that you believe 450.13(B) refers to the area above a drop ceiling as "hollow space"?

What part of a building not permanently closed in by structure would you say a hollow space is if it does not include the space above a suspended ceiling?

I agree with Pierre.

[ December 26, 2005, 11:41 AM: Message edited by: iwire ]

 

[websparky]

Re: 112 KVA

I agree with Pierre.

Both you and Pierre need to read the OP and the code a little more carefully before shooting off a reply.

 

[pierre]

Re: 112 KVA

Shooting off a reply???
I am not too sure what you mean by that.
My post is simply a section number with a question mark, what you imply from it does not necessarily mean what I posted.

I actually post some times just for this kind of reaction. To see if I am somewhere in the "ballpark"

Now Dave, what do you mean by your last post? My post was questioning the size of the transformer in the suspended ceiling, as I see it, more than 50kva is not permitted in such a location. I was not responding to your last sentence, but the fact that you saw the 112 kva transformer in the ceiling location.

Dave, enlighten me, I always want to try to understand what I already don't know.

[ December 26, 2005, 12:36 PM: Message edited by: pierre ]

 

[iwire]

Re: 112 KVA

Originally posted by websparky:

I agree with Pierre.

Both you and Pierre need to read the OP and the code a little more carefully before shooting off a reply.

Dave I read the opening post and I see this.

Originally posted by websparky:
On a final inspection of a new restaurant last week I discovered a 150 KVA dry type transformer suspended above the suspended ceiling.

That sounds to me like a 150 KVA dry type transformer is located above the suspended ceiling.

IMO In that case the insulation class is irrelevant. It can't be there in the first place due to 450.13(B) and it being larger than 50 KVA.

But I have made plenty of mistakes before and will again.

How about filling us in as to why Pierre and I are mistaken?

 

[websparky]

Re: 112 KVA

Pierre and Bob,
Pierre's code reference was not relative because:

(B) Hollow Space Installations. Dry-type transformers
600 volts, nominal, or less and not exceeding 50 kVA..

The transformer is 150 KVA not 50 KVA whether there is hollow space or not.

 

[iwire]

Re: 112 KVA

Originally posted by websparky:
Pierre and Bob,
Pierre's code reference was not relative because:

(B) Hollow Space Installations. Dry-type transformers
600 volts, nominal, or less and not exceeding 50 kVA..

The transformer is 150 KVA not 50 KVA whether there is hollow space or not.

Dave IMO you applying 450.13(B) backward.

First 450.13 requires all transformers to be readily accessible.

450.13 Accessibility.

All transformers and transformer vaults shall be readily accessible to qualified personnel for inspection and maintenance or shall meet the requirements of 450.13(A) or (B).

That prohibits any size transformer to be installed in the hollow space above a suspended ceiling.

Now we get to 450.13(B)

(B) Hollow Space Installations. Dry-type transformers 600 volts, nominal, or less and not exceeding 50 kVA shall be permitted in hollow spaces of buildings not permanently closed in by structure, provided they meet the ventilation requirements of 450.9 and separation from combustible materials requirements of 450.21(A). Transformers so installed shall not be required to be readily accessible.

If the transformer is larger than 50 KVA 450.13(B) does not apply to it.

That leave 450.13 prohibiting any transformer larger than 50 KVA to be installed in a hollow space above the ceiling.

IMO you can not allow this transformer to remain.

But of course that is up to you.

[ December 26, 2005, 01:40 PM: Message edited by: iwire ]

 

[peter d]

Re: 112 KVA

Ok, I'm going to shoot off a reply. Actually, Pierre's code reference is totally relevant. It says that transfomers not exceeding 50kva are permitted in hollow spaces.

 

[websparky]

Re: 112 KVA

OK, so you guys are saying "hollow space" includes the space above a susspended ceiling?

 

[pierre]

Re: 112 KVA

Yes Dave, that is how I read this.

Thanks Peter! It is nice when someone agrees...especially when Bob does

BTW: did you see the nice little trade the Yanks recently made.... that enforces the statement... money talks, BS walks.

[ December 26, 2005, 02:02 PM: Message edited by: pierre ]

 

[jbwhite]

Re: 112 KVA

The 2005 handbook says "in hollow spaces of hung ceilings"

 

[iwire]

Re: 112 KVA

Originally posted by websparky:
OK, so you guys are saying "hollow space" includes the space above a suspended ceiling?

Yes that is my opinion.

If it is not a hollow space of a building not permanently closed in by structure what would you call it?

It still may or may not also be other space used for environmental air. Notice in that section (300.22(C)) they do not specifically say "The space above a suspended ceiling" but I think we are all in agreement that many times that is the space in question.

If your are interested here is the opinion of the 2002 NECH authors in regards to 450.13(B)

2002 NECH

Section 450.13(B) continues to permit the installation of dry-type transformers rated 600 volts or less and not exceeding 50 kVA in hollow spaces of hung ceiling areas, provided these spaces are fire resistant, ventilated, and accessible. According to 300.22(C)(2), transformers are permitted to be installed in hollow spaces where the space is used for environmental air provided the transformer is in a metal enclosure (ventilated or nonventilated) and the transformer is suitable for the ambient air temperature within the hollow space. Of course, the requirement of 450.13(B) applies to transformer installations in ?other spaces used for environmental air.?

 

[websparky]

Re: 112 KVA

Thanks Bob for clearing this up. I was having a discussion with an electrician about the "over 112 1/2 KVA" section of the code and how it had to follow the first part of "all transformers" before it got to part 2. I must agree with others on the code book not being clear enough for some to follow.

Thanks to all,

 

[peter d]

Re: 112 KVA

Originally posted by pierre:
Thanks Peter! It is nice when someone agrees...especially when Bob does

BTW: did you see the nice little trade the Yanks recently made.... that enforces the statement... money talks, BS walks.

True enough...you have to be be pretty brave to walk around most New England cities wearing Yankee paraphenalia. And yes, it's all about the money apparently. :roll: