LOTO

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iceworm

Curmudgeon still using printed IEEE Color Books
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If the disconnect switch is locked in the closed (ON) position how can you open it? ...

I've seen it where a business will lock a disconnect on the exterior of a building. ....

... I would not lockout a breaker in the closed position, ...

Locking out breakers in the closed position is done all the time in industrial maintenance. ...

I am not clear about what sort of maintenance would require locking a breaker closed.

Truly priceless
:rotflmao::rotflmao::rotflmao:
 

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.
 

ActionDave

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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.
.
Here is the part that makes me pretty sure he is not locking disconnect on.
I am in need of qualified opinions as I have a problem. I have been told that it is ok to install a padlock on an energized disconnect. I have been reassured that the disconnect can be turned off with the said lock in place. The customer's safety personnel (large auto company) also said it was ok. I have been in the trade 37 years and never had someone tell me it was ok. The reason being is the OEM doesn't want to lose his lock.
Any comments? Yeah I know you can't fix stupid, but...
 

Jraef

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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.

.
 

iwire

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Location
Massachusetts
Something about this is all wrong. I know of no disconnect switch that, if locked in EITHER position, can still be changed! .

This one and others like it can be

$(KGrHqZHJE0FG9ufpk(JBR4Ej4(f0g~~60_35.JPG


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)
... If OP just wants a place to store the lock and the switch can still be turned off - so what. ...

Here is the part that makes me pretty sure he is not locking disconnect on.
Whoa - two that actually read the OP. All right.

Something about this is all wrong. I know of no disconnect switch that, if locked in EITHER position, can still be changed! ....
And one more that didn't.

This one and others like it can be

$(KGrHqZHJE0FG9ufpk(JBR4Ej4(f0g~~60_35.JPG


When the switch is in the on position you can lock the lock in the 'off' hole and still operate the switch normally.
And one still trying to herd the cats.

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
 

rlqdot

Member
Location
St. Louis, MO - USA
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Professional Engineer (multiple states) - building design
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.

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.
 
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