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 Post subject: returning loto to energized position
PostPosted: Mon Jun 11, 2012 1:50 am 

Joined: Sun Nov 16, 2008 12:01 pm
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I understand the debat about being able to loto a piece of equipment by machine operators but what about when the loto is removed and the breaker is returned to the on position ,would that be cosidered a safe operation. Not all equipment is started with a push button, A lot of equipment is started with floats , metering devices and the like where the operator might not be thinking about when turning back on equipment.
Also some equipment is loto because it is not functing correctly is this a situation for a QW or a operator to loto ?


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PostPosted: Mon Jun 11, 2012 7:11 am 

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PUCKMAN wrote:
I understand the debat about being able to loto a piece of equipment by machine operators but what about when the loto is removed and the breaker is returned to the on position ,would that be cosidered a safe operation. Not all equipment is started with a push button, A lot of equipment is started with floats , metering devices and the like where the operator might not be thinking about when turning back on equipment.
Also some equipment is loto because it is not functing correctly is this a situation for a QW or a operator to loto ?


There should be some type of a "stop" switch or manual switch that is required on pumping systems so the operator can turn it to manual or off when locking out. This is the first step of a lockout to isolate all energy sources before turning a breaker off. If your equipment does not have this isolation device, it needs one. Never throw a breaker under load. This creates the arc that could cause the flash or worse blast!!


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PostPosted: Tue Jun 12, 2012 8:27 am 
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"Never throw a breaker under load"
Is not entirely correct, and indeed is part of the reason there is a" close and latch" rating. Any circuit beraker protecting a transformer can not be closed any other way, but under load. But yes if you are thinking of just motor loads, and have the option, closing unloaded is best, but does not crate an arc that is any worse than the one caused by operating a contactor to start that same load.

As far as tjhe orioginal question, once a piece of equipment is in a state where it COULD start automatically, it IS "on" even if it is not "running".


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PostPosted: Sun Jun 17, 2012 4:19 am 

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Circuit breakers are designed for far fewer operations than motor starters. For motor loads, my advice is to make sure the motor is off via its starter (whether through an HOA switch or some other override) whenever opening or closing its upstream breaker. For main breakers in lighting and receptacle panelboards, I recommend turning off all branch breakers before turning on the main, then turning on branch breakers one at a time. For transformers, you don't have an option. Even if there is no load on the secondary, the transformer itself will require an initial magnetizing current. Depending on the magnetic orientation of the transformer when it was deenergized and the phase state of the feeder at the instant of energizing, the inrush current will be more or less. Fortunately transformers do not require service very often, unlike motors.


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PostPosted: Sun Jun 17, 2012 5:27 am 
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PUCKMAN wrote:
Also some equipment is loto because it is not functing correctly is this a situation for a QW or a operator to loto ?


Your question is ambiguous. First you have to answer...is this for a speciality industry such as mining, utility, maritime, or construction? Is it a general facility but the nature of the work has become construction in reality? Second, is this an operations lockout with a procedure in place (Subchapter O)? Is it a general lockout (Subchapter J)? Is it an electrical lockout (Subchapter S)? Is it being returned to normal service or is it being returned to service as part of the maintenance work such as checking motor rotation? Is this a complex lockout scenario involving multiple shifts, crews, or other situations where a lockbox or crew lockout procedure would be required, or a "simple" one requiring only one man, one lock? Is this an operations lockout with clearance procedures such as for a utility where locks aren't even involved at all? Are tags involved and if so, how? Is this a trivial case such as a power hand tool where the worker can be 100% in control of the energy source at all times? You need to know the answers to these questions because the answer changes drastically depending on your answers.

The biggest mistake that I have seen EVERY company I have ever worked for make is that they get completely confused by OSHA's LOTO rules and completely and utterly misapply them. The problem is that when someone says "LOTO", they are being ambiguous. OSHA has several DIFFERENT methods in different sections all generally referred to as "lockout" or "LOTO", even though many of them don't even require a tag. Some do require "try", some don't. Some don't even require a lock. Each section looks superficially similar but they are definitely NOT the same. The rules do adapt to MIXING different sections but you have to read closely how to do this. For instance Subchapter S specifically includes provisions for piggy-backing onto a Subchapter J lockout. Worse yet, even within those sections, you can have lots of variations. For instance you can have both "simple" and "complex" lockouts, and in the case of Subchapter R, they have an entirely different "operations" LOTO that looks like stepping back decades again and would scare anyone outside of the utility industry. Subchapter J has a "removing locks for testing purposes" rule while Subchapter S does not...and mixing Subchapter S on top of Subchapter J thus results in confusion.

There are at least 8 different kinds of LOTO in OSHA regulations notwithstanding modified sections such as the additional rules for confined spaces:
General LOTO for maintenance, Subchapter J
LOTO for operations purposes, Subchapter O
Electrical LOTO, Subchapter S
G/T/D LOTO, Subchapter R
Construction LOTO, Article 1926.
LOTO in mining areas, MSHA regulations (3 sections).
Maritime (less familiar with these).

Subchapter O is used when you have a particular procedure in place but is when the equipment is "running". It might be used for instance to disable the machine to clear a jam but that's as far as it goes. It is the most flexible rule.

The construction rules are not much different except that tagging is specifically required (it is optional in other subchapters) for electrical equipment irrespective of whether a lock is present or not.

Subchapter J is for general lockouts and is the most widely used and referenced section. It is used generally for all maintenance LOTO situations of any kind EXCEPT electrical work. Qualified workers do not enter into the picture. This section applies as long as electrical work is not being done for most cases. For instance if you have a pump or a linkage or anything else that is not functioning but it is not an electrical problem, this section applies. The size/scope of the work determines whether Subchapter J or Article 1926 should be used. Watch out for this! Many companies unknowingly cross the line into construction work. If you implement Subchapter J AND require tags in addition to locks you will fulfill the requirements of both sections.

Subchapter R is for generation/transmission/distribution equipment only. It describes at leat one LOTO scheme where the workers involved don't actually put locks on at all (clearance procedures through operations).

Subchapter S is for ELECTRICAL lockouts and is based on the procedures in NFPA 70E. At some point even if it's just for testing for absence of voltage, potentially energized equipment is involved. This must be used and Subchapter J and O may not be substituted for S (though R must be substituted where it applies). Construction may also apply and displace S and R again, situation dependent.

I strongly recommend as a bare minimum to figure out whether or not you fall into a "specialty" industry/category (utility, mining, maritime, construction). If so, familiarize yourself with YOUR section. Otherwise, read Subchapter J, O, and S. Understand how those 3 interact with each other. Also pay particular attention to the details in the beginning of 1910 and understand when CONSTRUCTION (1926) applies. Read that one too. Their LOTO rules are about 3 paragraphs long. The only catch in there is that J and S do NOT require tags while 1926 definitely does.


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PostPosted: Mon Jun 25, 2012 7:26 am 
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PUCKMAN wrote:
I understand the debat about being able to loto a piece of equipment by machine operators but what about when the loto is removed and the breaker is returned to the on position ,would that be cosidered a safe operation. Not all equipment is started with a push button, A lot of equipment is started with floats , metering devices and the like where the operator might not be thinking about when turning back on equipment.
Also some equipment is loto because it is not functing correctly is this a situation for a QW or a operator to loto ?

I have difficulty of understanding what your concern is, but will make some general comments that may help you clarify your issues.
  • The device that provides the means of disconnect, eg. it interrupts the continuity of the phase conductors - all of them - is the OSHA acceptable lockout device. It should be lockable, mechanically securable in the open position.
  • It should be tested/tried that ALL phases of the electrical supply are securely interrupted. This is obvious from the electrical standpoint, where actual work is expected to be performed on energizeable parts. It is not so obvious when expecting to work only on the mechanical parts of the machinery, but it is true that a 3 phase equipment CAN start to rotate with only 2 phases present.
  • A contactor is not an acceptable lockout device.
  • No components - such as poushbuttons, etc. - in the secondary/auxiliary/control circuit constitute an acceptable lockout device.
  • Devices starting/stopping automatically is an issue for the procedure the operator who performs the LOTO. Before the LOTO is removed, the operator must assure that returning the machine to operation is safe and that all energized parts are properly guarded/covered and all mechanical blocks removed.
  • Operating an electrical LOTO device normally requires the donning of the PPE rated for the arc-flash hazard level involved.


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PostPosted: Tue Jun 26, 2012 5:05 pm 
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Quote:
No components - such as poushbuttons, etc. - in the secondary/auxiliary/control circuit constitute an acceptable lockout device.


Not true. In a lot of equipment over 1 kV, it must energize to change states. A lot of >1 kV breakers are effectively disabling power to the control circuit. Without power, it cannot physically change states. It meets OSHA requirements.

Quote:
The device that provides the means of disconnect, eg. it interrupts the continuity of the phase conductors - all of them - is the OSHA acceptable lockout device. It should be lockable, mechanically securable in the open position.

Not true again, and neither are any of the other statements. This is the kind of misinformation that I referred to. See Subchapter O.


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PostPosted: Tue Jun 26, 2012 5:05 pm 
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Quote:
No components - such as poushbuttons, etc. - in the secondary/auxiliary/control circuit constitute an acceptable lockout device.


Not true. In a lot of equipment over 1 kV, it must energize to change states. A lot of >1 kV breakers are effectively disabling power to the control circuit. Without power, it cannot physically change states. It meets OSHA requirements.

Quote:
The device that provides the means of disconnect, eg. it interrupts the continuity of the phase conductors - all of them - is the OSHA acceptable lockout device. It should be lockable, mechanically securable in the open position.

Not true again, and neither are any of the other statements. This is the kind of misinformation that I referred to. See Subchapter O.


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PostPosted: Fri Jul 06, 2012 5:42 am 
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PaulEngr wrote:
Not true. In a lot of equipment over 1 kV, it must energize to change states. A lot of >1 kV breakers are effectively disabling power to the control circuit. Without power, it cannot physically change states. It meets OSHA requirements.

OSHA 1910.147(b)
Quote:
Definitions applicable to this section.
...
Energy isolating device. ... Push buttons, selector switches and other control circuit type devices are not energy isolating devices.


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PostPosted: Fri Jul 06, 2012 3:23 pm 
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jghrist wrote:
OSHA 1910.147(b)


OK, you quoted Subchapter J lockout which is a general and not an electrical lockout. What about Subchapter O? R? S? 1926?

1910.147(a)(1)(i) This standard does not cover...Exposure to electrical hazards from work on, near, or with conductors or equipment in electric-utilization installations, which is covered by subpart S of this part...Normal production operations are not covered by this standard (See Subpart O of this Part).

Further, you should quote the ENTIRE section:
Energy isolating device. A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy. Push buttons, selector switches and other control circuit type devices are not energy isolating devices.

The fundamental criteria here is that it must be a mechanical blocking mechanism, NOT an electrical one, despite the fact that there is no difference from a safety point of view. In the case of push button and selector switch controls, the mechanism itself is not blocked from moving. However if the energy source providing motive power to the circuit breaker is mechanically blocked, it counts. Take a look at a magnetic mechanism on a circuit breaker such as an Admag from ABB. Mechanically blocking in the power source blocks the mechanism.


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PostPosted: Fri Jul 06, 2012 3:42 pm 
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jghrist wrote:
OSHA 1910.147(b)


OK, you quoted Subchapter J lockout which is a general and not an electrical lockout. What about Subchapter O? R? S? 1926?

1910.147(a)(1)(i) This standard does not cover...Exposure to electrical hazards from work on, near, or with conductors or equipment in electric-utilization installations, which is covered by subpart S of this part...Normal production operations are not covered by this standard (See Subpart O of this Part).

Further, you should quote the ENTIRE section:
Energy isolating device. A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy. Push buttons, selector switches and other control circuit type devices are not energy isolating devices.

The fundamental criteria here is that it must be a mechanical blocking mechanism, NOT an electrical one, despite the fact that there is no difference from a safety point of view. In the case of push button and selector switch controls, the mechanism itself is not blocked from moving. However if the energy source providing motive power to the circuit breaker is mechanically blocked, it counts. Take a look at a magnetic mechanism on a circuit breaker such as an Admag from ABB. Mechanically blocking in the power source blocks the mechanism.


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