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#184548 - 02/12/09 06:18 PM Transformer bolted to floor *****
Powerplay_09 Offline
New Member

Registered: 02/11/09
Posts: 1
Loc: B.C. Canada
I had a friend who always bolts his transformers to the floor, but was questioned by another electrician whether it was necessary...we'd like to know if there is a reference in the CEC about having to bolt transformers to the floor or perhaps a building code requirement under "seismic"?

Thanks, any feedback would be appreciated!

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#185480 - 03/16/09 12:03 PM Re: Transformer bolted to floor [Re: Powerplay_09]
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
Well we don't lean the panels against the wall either. All equipment has to be securly mounted.

The building code defines these things and in a seismic area the rules are stricter often requiring snubbers and seismic rated anchors etc.
2-118 refers us to Appendix G which are the many Building code references.

I can tell you that they must be secured but it surprises me that the rule that says so is not so easy to find and I will be looking.

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#185640 - 03/21/09 08:59 PM Re: Transformer bolted to floor [Re: mikesh]
Eddy Current Offline
Member

Registered: 09/26/06
Posts: 112
Loc: Ontario,Canada
26-248(1)Transformers of the dry-core open-ventilated type shall be mounted so that there is an air space of not less than 150mm between.............
26-240(4)Transformers shall be protected from mechanical damage.
I'd say either one of those covers it



Edited by Eddy Current (03/21/09 09:00 PM)

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#185641 - 03/21/09 10:31 PM Re: Transformer bolted to floor [Re: Eddy Current]
twh Offline
Member

Registered: 03/11/04
Posts: 898
Loc: Regina, Sask.
I carry a hot glue gun just for the purpose of mounting transformers on the floor. It also provides mechanical protection by providing some "give" if a fork lift hits it.

I'm not advocating leaning panels against the wall, but I've seen a few transformers hung by threaded rod from the ceiling and they move quite freely. Sitting on the floor is way more secure - without glue.

The other electrician, in the original post, has a good point. Are there any rules about mounting transformers? What is secure?

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#185644 - 03/22/09 10:25 AM Re: Transformer bolted to floor [Re: twh]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 884
Loc: Chicago Illinois USA
If it's suspended by unistrut on threaded rod it's always bolted to the unistrut. If bolting's good enough for the hanging ones it's good enough for the floor mounted ones.
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#185662 - 03/23/09 03:56 PM Re: Transformer bolted to floor [Re: ghost307]
mikesh Offline
Member

Registered: 06/07/06
Posts: 614
Loc: Victoria, BC, Canada
Originally Posted By: ghost307
If it's suspended by unistrut on threaded rod it's always bolted to the unistrut. If bolting is good enough for the hanging ones it's good enough for the floor mounted ones.

Be careful about that assumption. A transformer hanging from a ceiling might likely survive a seismic event where the one bolted to the floor does not. For example the hole that the bolt goes through can act as a bolt cutter if the hole is larger than the bolt. The side to side motion of a transformer can hammer on the bolt and shear it off. Bolts are much stronger in stretch than shear. the hanging transformer and its suspension will give in a shaker where the bolts on the floor mounted transformer shear off because it is more rigid.

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#185669 - 03/23/09 07:24 PM Re: Transformer bolted to floor [Re: mikesh]
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
Ummmm Then do you Require Large MCC sections or Switchgear to be Bolted to the Floor also?? What if its mounted on Steel Rails like a lot are in Factorys?? Do you then require it be Welded to the rails????

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#185673 - 03/23/09 10:23 PM Re: Transformer bolted to floor [Re: Yoopersup]
electure Offline

Member

Registered: 12/24/00
Posts: 4226
Loc: Fullerton, CA USA


In California, you'd get a big fat red tag for not bolting down transformers, MCCs or switchgear......

The inspector would probably walk away shaking his head, laughing.

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#185676 - 03/24/09 07:25 AM Re: Transformer bolted to floor [Re: electure]
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
Then in California do they Require Gear WELDED to rails when gears set on them???
Do you know what I mean by metal rails???

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#185678 - 03/24/09 07:40 AM Re: Transformer bolted to floor [Re: Yoopersup]
ghost307 Offline
Member

Registered: 05/09/05
Posts: 884
Loc: Chicago Illinois USA
When I was at GE, we'd void your warranty if you didn't bolt down the MCC, Switchboards and Switchgear.
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