OT: LOTO Absense of energy verifcation

Plastic said:

https://www.panduit.com/en/landing-pages/verisafe.html

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This is the one we started installing.

mutabi said:

HBut if an operator is changing a grinding wheel, instead of locking it out and attempting to restart the machine, they will now have to summon an electrician who will have to suit up and verify the absence of power.

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This is where the OSHA minor servicing exemption to LOTO comes in to play.

It allows the use of alternative means for an operator to make minor tool changes during production.

But you will need to convince your safety department to implement this.

I was bit by a 120V wire snake.
One of our guy's rewired this panel as an upgrade to an old machine.
I went to plug in an Ethernet cable to the HMI. This wire snake jumped out and tagged me on my right hand and I grounded thru my left heel. I have permanent nerve damage from that.

JesperMP said:

From this side of the pond.
Testing for absence of energy, with the testing of the test device itself being part of the procedure, is mandatory for doing work inside electrical cabinets. ...

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There is the salient point right there. The requirements for "removing energy" for performing normal work related tasks such as changing a grinding wheel, require a "Lock-Out / Tag-Out" procedure. "Test - Verify - Test" procedures involving the need for an electrical meter are for the ELECTRICIANS who will be working on the ELECTRICAL EQUIPMENT, not the normal tool / machine tasks.


The bigger change that most people don't realize has been use of the term "removal of energy" as a more expanded concept that, as said by Phil Buchanan, includes all potential sources of energy, sometimes referred to as WAGES, meaning Water, Air, Gas, Electricity and Steam.

Echoing what jaref’s post about removal of all energy, a GM plant where I did a lot of contract work had very detailed laminated posters at each machine showing all points of lockout needed. This included electrical, pneumatic, hydraulic, and any stored energy sources like springs, etc.

Each person was issued 6 locks and they were very strict about enforcing LOTO.

Regarding the Graceport and Panduit indicators, can someone answer me this question: How do you know it is wired to the proper place?

With all of the crappy wiring and engineering that most of us have seen, are you willing to trust your life that someone else wired it correctly, or that nothing has changed?

Not me.

mutabi said:

Hey guys, OT I know, but I feel like there is another experience in this thread to get some good feedback.

So right now in our facility, our LOTO program allows equipment mechanics, operators, electricians to lock equipment out. Verification up until this point involved trying to restart the equipment. Recently though they have added that verification must be done with a meter.

Now, if a work is being done in a cabinet, then yes I agree, that needs to be done and there are plenty of regs for that. But if an operator is changing a grinding wheel, instead of locking it out and attempting to restart the machine, they will now have to summon an electrician who will have to suit up and verify the absence of power. To me that seems excessive. You will have electricians chasing operators and mechanics all day verifying the absence of power.

What is the industry norm when it comes to verifying something is safely locked out? Is this the direction that things are going?

TIA

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I think you need to revisit the LOTO procedure, I aggree that things should be locked out, but a definition of a hand tool needs to be added.


So a Weld shop worker changing a disc on a "portable" grinder or a drill bit on a "Hand Drill" doen't need loto, only as others said. Cable in Hand Method.


But a Fixed Bench Grinder not thats not a hand tool so need LOTO.


Exceptions need to be made to rules for Lathe Tool changes and Pillar drills. But these should have suitable guarding and lockouts on gaurds if required.




Rules like these need a modicom of common sense applied to them. What your suggesting is I need a LOTO to isolate a phone charger before I plug in my phone to charge.... #DAFT.

jraef said:

There is the salient point right there. The requirements for "removing energy" for performing normal work related tasks such as changing a grinding wheel, require a "Lock-Out / Tag-Out" procedure. "Test - Verify - Test" procedures involving the need for an electrical meter are for the ELECTRICIANS who will be working on the ELECTRICAL EQUIPMENT, not the normal tool / machine tasks.

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By electrical equipment, you mean purely electrical equipment such as control cabinets and switchboards ?
Drive motors for f.eks. pumps and conveyors do not need testing for absence of electrical energy ?

We keep LOTO simple here at our 2200MW power station. All electrical isolations are inspected for a physical break in the switch fuse blades from the bus and the plant item to be worked on is verified against the permit by 3 different people.

JesperMP said:

By electrical equipment, you mean purely electrical equipment such as control cabinets and switchboards ?
Drive motors for f.eks. pumps and conveyors do not need testing for absence of electrical energy ?

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If a pump is being replaced or the plumbing repaired, that motor, or the entire panel, would need locked-out. It is common now to have a separate disconnect at each motor on lines.

If an operator is replacing or cleaning a filter on a pump, then that might not fall into the LOTO category - but may be required by management or safety policy.

Aabeck said:

It is common now to have a separate disconnect at each motor on lines.

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Yes, we have local disconnects at every motor or coupled motors (up to 2 motors).

Aabeck said:

If a pump is being replaced or the plumbing repaired, that motor, or the entire panel, would need locked-out.

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But do you need to verify absence of electrical energy with testing of the disconnecting device ? That is my question.
I ask, because in a realistic scenario, the defective pump will be powered off in order to not cause further damage, not by the local repair disconnect, but by the control system. Thus, you cannot perform the test of the disconnect (because there is no voltage already). Essentially you have to blindly trust the disconnect when you start working on the pump.

What I do when replacing a locally disconnected motor is check for absence of power when I open the motor doghouse.

If it has screw terminals this is easy, but larger ones with rubber taped copper split bolts I still get my probes down into the copper and test for voltage - if I get none I then check for ohms to make sure I am contacting the copper. No ohms means I am measuring the rubber splice tape.

One thing I am proud of is in 35 years of working on 240/400/480/600V electrical control panels I have never been electrocuted (other than 120 because I frequently work on that live both at work and home)

for safesty, i don't think there could really be a ''one size fit all'' solution and each case would need to be evaluated for proper actions.

For a fixed machine, blindly lock it out and ask an electrician to check if there 0 voltage may fulfill the paper requirements but doesn't worth much for real safety if no one think about the real risks of this specific action.....
Let say the operator lock the wrong one and the electrician check the one opened and say: ok 0 voltage....who will be liable for the accident ?

IT start from a properly taged equipment and locking process.
Then the restart attempt is to me something important in many cases but may not clear everything everywhere...
Checking for 0 voltage could be appropriate but not worth much for others....(If the automatic system is not triggering the equipment or something above as been opened it would read 0v, wont restart but still not be safe to work on)

And few talk about sticked phase on a switch but this remain harmful when playing with wires but has no effect on someone replacing a cutting tool, a motor won't restart with a single phase powered....

Imo you need to evaluate each work separately and take the proper actions to avoid being hurt. Your company needs to assist you and provide all help but at the end, you are still the most responsible of your own safety. Not assuming everyone else would have been done it for you...