- Location
- Massachusetts
:lol::lol::lol:
LOTO
- Thread starter dweidner58
- Start date
- Status
:lol::lol::lol:
iceworm
Curmudgeon still using printed IEEE Color Books
- Location
- North of the 65 parallel
- Occupation
- EE (Field - as little design as possible)
Truly priceless
:rotflmao::rotflmao::rotflmao:
JFletcher
Senior Member
- Location
- Williamsburg, VA
Yeah, I see it now. I mistyped my thoughts: locking out breakers in the open (de energized) position is done all the time. I have seen valves locked open/shut, but never a breaker in the energized position.
mgookin
Senior Member
- Location
- Fort Myers, FL
Maybe you sell coffee for $5 per cup and pay your employees less than what they think is fair?
kwired
Electron manager
- Location
- NE Nebraska
OP does not necessarily say he is locking the disconnect in the ON position. That is a possibility though and has been part of what some have been talking about.
Locking a breaker or switch ON is not LOTO, it is just assurance that it takes extra effort to turn the switch off and maybe helps prevent inadvertent turning off something that you don't want off without having to intentionally go through more steps before you can turn it off.
If OP just wants a place to store the lock and the switch can still be turned off - so what. It is not locked on or off until the lock is moved to the appropriate position.
Locking a breaker or switch ON is not LOTO, it is just assurance that it takes extra effort to turn the switch off and maybe helps prevent inadvertent turning off something that you don't want off without having to intentionally go through more steps before you can turn it off.
If OP just wants a place to store the lock and the switch can still be turned off - so what. It is not locked on or off until the lock is moved to the appropriate position.
- Occupation
- Licensed Electrician
Here is the part that makes me pretty sure he is not locking disconnect on.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Something about this is all wrong. I know of no disconnect switch that, if locked in EITHER position, can still be changed! What would be the point of a lock? :blink::? You can lock a disconnect in the Off position (Open) or you can lock a disconnect in the On position (Closed). When locked in either position, it is LOCKED in THAT position.
The only possible misinterpretation of that concept here is that if you are using a CIRCUIT BREAKER as a disconnect device, and lock it in the On position, the breaker can still TRIP in case of a fault. The same might be true of a Bolted Pressure (Pringle) Switch I think, by virtue of using a shunt trip mechanism tied to a blown fuse indicator, but I'm not 100% sure, I've never been asked to do this.
More likely theory: the OP is referring to locking the DOOR closed, not the switch mechanism. That makes more sense to what he was saying. The OEM wants to have a lock available at the machine so that when he is there servicing it, he has a lock available to him (I guess he has trouble remembering to bring one with him?). So he wants to put his lock on the hasp of the disconnect so that when he arrives, he has a lock right there for him and can remove it from the hasp, then use it to lock OFF the disconnect while he works.
Nothing about LOTO applies to this. LOTS of enclosures are locked closed to prevent unauthorized access. My only concern would be that if the OEM's lock is locking the disconnect enclosure, and the user wants to perform routine maintenance on the disconnect, such as a thermal scan or something, then they are likely to cut his lock off, so he loses it anyway. If it is a FUSED disconnect, then fuggetaboutit. Someone may need to change fuses, and if production is stopped while they try to figure out who's lock it is, then end up cutting it anyway, the user could lose huge amounts of money in the delay.
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The only possible misinterpretation of that concept here is that if you are using a CIRCUIT BREAKER as a disconnect device, and lock it in the On position, the breaker can still TRIP in case of a fault. The same might be true of a Bolted Pressure (Pringle) Switch I think, by virtue of using a shunt trip mechanism tied to a blown fuse indicator, but I'm not 100% sure, I've never been asked to do this.
More likely theory: the OP is referring to locking the DOOR closed, not the switch mechanism. That makes more sense to what he was saying. The OEM wants to have a lock available at the machine so that when he is there servicing it, he has a lock available to him (I guess he has trouble remembering to bring one with him?). So he wants to put his lock on the hasp of the disconnect so that when he arrives, he has a lock right there for him and can remove it from the hasp, then use it to lock OFF the disconnect while he works.
Nothing about LOTO applies to this. LOTS of enclosures are locked closed to prevent unauthorized access. My only concern would be that if the OEM's lock is locking the disconnect enclosure, and the user wants to perform routine maintenance on the disconnect, such as a thermal scan or something, then they are likely to cut his lock off, so he loses it anyway. If it is a FUSED disconnect, then fuggetaboutit. Someone may need to change fuses, and if production is stopped while they try to figure out who's lock it is, then end up cutting it anyway, the user could lose huge amounts of money in the delay.
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- Location
- Massachusetts
This one and others like it can be
When the switch is in the on position you can lock the lock in the 'off' hole and still operate the switch normally.
iceworm
Curmudgeon still using printed IEEE Color Books
- Location
- North of the 65 parallel
- Occupation
- EE (Field - as little design as possible)
Whoa - two that actually read the OP. All right.
And one more that didn't.
And one still trying to herd the cats.This one and others like it can be
When the switch is in the on position you can lock the lock in the 'off' hole and still operate the switch normally.
Good work Bob. Hang in there.
I'm down to watching this like a car wreck. Can't keep one's eyes off while driving by.:ashamed1:
ice
- Location
- Massachusetts
rlqdot
Member
- Location
- St. Louis, MO - USA
- Occupation
- Professional Engineer (multiple states) - building design
circuits supplying power to emergency lights (or other emergency / life safety loads) are frequently locked in the closed / energized position. they still have the ability to trip on short circuit or overload but cannot be turned off by anyone other than a person with key.
- Status