Locking a disconnect

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It's funny that 110.26 won't allow someone to block the working space because it would limit the space required "to permit ready and safe operation" yet when they reach the equipment it's permitted to be locked on.
 
VIII. Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces
620.71 Guarding Equipment.
(A) Motor Controllers. Motor controllers shall be permitted outside the spaces herein specified, provided they are in enclosures
with doors or removable panels that are capable of being locked in the closed position and the disconnecting means is located adjacent to or is an integral part of the motor controller....

695.4 Continuity of Power. Circuits that supply electric motor-driven fire pumps shall be supervised from inadvertent disconnection as covered in 695.4(A) or (B).
(3) Disconnecting Means. All disconnecting devices that are unique to the fire pump loads shall comply with items (a) through (e).
(a) Features and Location ? Normal Power Source. The disconnecting means for the normal power source shall comply with all of the following:
(1) Be identified as suitable for use as service equipment
(2) Be lockable in the closed position ....

695.4 Continuity of Power.
(3) Disconnecting Means.
(4) Be located sufficiently remote from other building or other fire pump source disconnecting means such that inadvertent operation at the same time would be unlikely
(b) Features and Location ? On-Site Standby Generator. The disconnecting means for an on-site standby generator(s) used as the alternate power source shall be installed in accordance with 700.10(B)(5) for emergency circuits and shall be lockable in the closed position.
(e) Supervision. The disconnecting means shall be supervised in the closed position by one of the following methods:
(1) Central station, proprietary, or remote station signal device
(2) Local signaling service that causes the sounding of an audible signal at a constantly attended point
(3) Locking the disconnecting means in the closed position ....

I also believe disconnects for fire alarm systems can be locked on (perhaps in NFPA Life Safety 101)
 
Both articles 700.12 (F) exception No.1 and 701.12 (G) exception dealing with Unit Equipment (battery backed emergency lights) require a lock on feature.
 
How would you actually achieve this? I've had a similar discussion regarding the main disconnect feeding a school building. It was located on the exterior of the building and the owner feared that students may come by and flip it to the off position just to be funny. We discussed a lockable enclosure around the disconnect, but we never determined a way to lock the (existing) disconnect in the "on" position without drilling a whole for a pad lock near the switch.
 
jcbabb said:
... we never determined a way to lock the (existing) disconnect in the "on" position without drilling a whole for a pad lock near the switch.
Click to expand...
This is often the 'approved by manufacturer' method. Check your installation instructions.
 
The fire depts. here say no to locking disconnects in the on position. Kids would flip them down at a strip mall, we tried to lock them all on. it worked for about three days.
 
Can you imagine a traffic signal disconect with no lock in the on position? They do have disconects and they are locked on.
 
Hv&Lv said:
The fire depts. here say no to locking disconnects in the on position. Kids would flip them down at a strip mall, we tried to lock them all on. it worked for about three days.
Click to expand...

Pretty silly since bolt cutters should be readily available on the fire truck.
 
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