Altering a disconnect

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knights1

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The facilities manager where I work wants the disconnects for all of our exhaust fans,that are used to remove heat from the building, locked in the on position to keep employees from turning them off. This would require drilling a hole through the handle and a portion of the box. I have searched the NEC and can't find where it would be against code. Can anyone point me to the correct area or is this legal?
 
knights1 said:
The facilities manager where I work wants the disconnects for all of our exhaust fans,that are used to remove heat from the building, locked in the on position to keep employees from turning them off. This would require drilling a hole through the handle and a portion of the box. I have searched the NEC and can't find where it would be against code. Can anyone point me to the correct area or is this legal?

110.3(B) or 110.12(C) maybe?
 
I agree. 110.3(B) say: Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.
 
resistance said:
110.3(B) say: Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.


Yes that is true.

But where does either the listing or labeling indicate a lock can not be added?
 
iwire said:
Yes that is true.

But where does either the listing or labeling indicate a lock can not be added?
Where does it say it can be added? :grin:

Why are you picking on me. Pick on 480, he started it, I agreed! :) :grin:


I'm seeing 110.3(B) as meaning it should be utilized as manufactured. If it didn't come with a space to lock the device, then it wasn't intended to be locked--there-by violating 110.3(B).
 
iwire said:
Yes that is true.

But where does either the listing or labeling indicate a lock can not be added?

The lock can be added. But the OP states the disco cannot be locked in the closed position, which is what he wants.
 
iwire said:
But where does either the listing or labeling indicate a lock can not be added?
Or, for that matter, the instructions that came with them? I agree, this is not likely to be able to stop the facilities manager from doing what he wants.

But if I were that person's boss, and if he proposed doing this, I would want to ask what problem this is intended to solve. Has there been a recent rash of disgruntled employees turning stuff off as a way of expressing their displeasure with some company policy? If you don't have a problem, then it is a waste of company resources to spend money to fix the problem.

I saw a sign once, and I wish I had written down its exact words. I don't remember them exactly, and the original version was quite elegantly worded. But it went something like this:
There is nothing less efficient than looking for a better way to do something that shouldn't be done in the first place.
 
480sparky said:
But the OP states the disco cannot be locked in the closed position, which is what he wants.
There is no NEC prohibition against that. The required function of the disconnect is to ensure the equipment remains deenergized during maintenance, or more precisely, to give the maintence person absolute assurance that the equipment remains deenergized. The disconnect is not required to serve as a readily available means to turn off the equipment in the event of an emergency.
 
I would think the lock on device would have to be listed as an accessory for that disconnect
 
charlie b said:

There is no NEC prohibition against that. The required function of the disconnect is to ensure the equipment remains deenergized during maintenance, or more precisely, to give the maintence person absolute assurance that the equipment remains deenergized. The disconnect is not required to serve as a readily available means to turn off the equipment in the event of an emergency.

He want to lock it in the CLOSED position, and states the disco has to provisions for that.

He wants to drill a hole through the handle and side of the disco in order to place a padlock through the handle and keep the circuit ON.
 
mpd said:
I would think the lock on device would have to be listed as an accessory for that disconnect

Why would you assume that?

I can place standard pad lock in most disconnects.

Are you saying I need a pad lock listed for that purpose?
 
resistance said:
I'm seeing 110.3(B) as meaning it should be utilized as manufactured.
But please take note that that is not what it says (reference: Charlie's Rule).

(Warning: The following is slightly Off Topic)
I feel free to invoke "Charlie's Rule" today, because I had to invoke it upon myself two days ago. We had a technical discussion, and I later had to retract my answer, admitting it was wrong, and reminding myself that the code does not, in fact, say what I thought it said. The issue was whether a 500 KVA transformer with a 120/208V secondary can serve a 2000 amp board with a 2000 amp main breaker. I discovered, much to my surprise, that the "Over 800 amps you go down with the OCPD rating" rule does not appear in Note 1 to Table 450.3(B).
 
I'm sure the manufact specs indicate how the lock should be applied to the device. It seems the manufact wants the device locked in the open position----for tag-out purposes. It seems 110.3(B) is the correct code to apply.
 
480sparky said:
The lock can be added. But the OP states the disco cannot be locked in the closed position, which is what he wants.

I understand that.

Drill a hole, install a pad lock, no harm, no foul.

Or are you saying I can not drill my own holes in an electrical enclosure?
 
resistance said:
I'm sure the manufact specs indicate how the lock should be applied to the device. It seems the manufact wants the device locked in the open position----for tag-out purposes. It seems 110.3(B) is the correct code to apply.

AHHHHH!

Please, please and please again.

Read what 110.3(B) really says.
 
mpd said:
iwire

do you have drill most disconnects to install a padlock?

Nope.

But I have drilled them for many other reasons.

But if you can't show me a disconnect that has instructions included in the listing and labeling that prohibit adding a lock I will do it.

Just like I will make a KO for a conduit.
 
iwire said:
I understand that.

Drill a hole, install a pad lock, no harm, no foul.

Or are you saying I can not drill my own holes in an electrical enclosure?

I knew enclosure drilling was coming!

I have a question. Do you believe the disco should be available for disconnect at any given moment--by any person--for safety reasons?
 
iwire said:
.....But if you can't show me a disconnect that has instructions included in the listing and labeling that prohibit adding a lock I will do it.....

Show me a listing for a disconnect that prohibits it's use on the outside of the Space Shuttle.

There's no way a manufacturer can possibly list every possible future use of their equipment, especially ones that could result in a violation of the listing.
 
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