Lock out of equipment near energized equipment

[mwuniseal]

Greetings,
I have control enclosures that contain breakers and motor starters that will need to be locked out individually. The motor starters are ABB, MS series manual motor starters coupled to ABB contactors. These units are designed to be individually locked out. I also have ABB breakers inside the control enclosure that will be locked out.
My question: Is there a insulated type of lock that can be used instead of a metal lock? The motor starters are mounted on DIN rail and are located right next to each other, so there is a concern of accidental contact with energized parts.
Thank you for your help.
Matt Wolf

 

[don_resqcapt19]

You need to redesign the panel so it has external lockouts. You would have to have PPE suitable for the arc flash hazard to even open the panel to apply the locks.

 

[just the cowboy]

Danger tag

Danger tag

Greetings,
I have control enclosures that contain breakers and motor starters that will need to be locked out individually. The motor starters are ABB, MS series manual motor starters coupled to ABB contactors. These units are designed to be individually locked out. I also have ABB breakers inside the control enclosure that will be locked out.
My question: Is there a insulated type of lock that can be used instead of a metal lock? The motor starters are mounted on DIN rail and are located right next to each other, so there is a concern of accidental contact with energized parts.
Thank you for your help.
Matt Wolf

Couple of things.

1. Who goes in the control panel, to put a lock on, not operators I hope.
2. Is new or existing, if new use a MCC.
3. If it is for maintenance a danger tag and tie wrap are allowed in a control panel then lock panel.

 

[Jraef]

You need to redesign the panel so it has external lockouts. You would have to have PPE suitable for the arc flash hazard to even open the panel to apply the locks.

Couple of things.

1. Who goes in the control panel, to put a lock on, not operators I hope.
2. Is new or existing, if new use a MCC.
3. If it is for maintenance a danger tag and tie wrap are allowed in a control panel then lock panel.

This is the problem often overlooked by people in going with the "group mounted motor starter" control panel concept, as opposed to an MCC with individual starters. The group mounted concept basically only works when you can lock off the ENTIRE panel via a single main disconnect. Opening the door to install "insulated" locks is not going to pass muster with any reasonable electrical safety program now, and EVERY employer is required to have an electrical safety program. The only thing that might be acceptable would be if the main disconnect is interlocked with the door and the switch can be opened and locked open, then the individual unit MS switch locked open, then the door closed and the main re-energized. In that case, no need for the lock to be insulated, there should be no live terminals in the box when opened (other than the line terminals of the Main, which should be shrouded at least).

In theory, you can also get the little rotary through-the-door disconnect handles that work for those MS switches so that they can be locked from the outside. I say "in theory" because I have done many many panels with 2 of those, a few with 3, one with 4. Even at two handles, it's often tough to get them to both line up perfectly when you want to close the door and make the shafts hit the handles at the right spot. 3 gets frustrating, 4 is damned near impossible.

 

[don_resqcapt19]

This is the problem often overlooked by people in going with the "group mounted motor starter" control panel concept, as opposed to an MCC with individual starters. The group mounted concept basically only works when you can lock off the ENTIRE panel via a single main disconnect. Opening the door to install "insulated" locks is not going to pass muster with any reasonable electrical safety program now, and EVERY employer is required to have an electrical safety program. The only thing that might be acceptable would be if the main disconnect is interlocked with the door and the switch can be opened and locked open, then the individual unit MS switch locked open, then the door closed and the main re-energized. In that case, no need for the lock to be insulated, there should be no live terminals in the box when opened (other than the line terminals of the Main, which should be shrouded at least).

In theory, you can also get the little rotary through-the-door disconnect handles that work for those MS switches so that they can be locked from the outside. I say "in theory" because I have done many many panels with 2 of those, a few with 3, one with 4. Even at two handles, it's often tough to get them to both line up perfectly when you want to close the door and make the shafts hit the handles at the right spot. 3 gets frustrating, 4 is damned near impossible.

We use door mounted rotary switches for the lockout of things like this (Allen Bradley 194E series as I recall). No issue with lining anything up, but you do have to get power wiring out to the door.

 

[Besoeker]

Greetings,
I have control enclosures that contain breakers and motor starters that will need to be locked out individually. The motor starters are ABB, MS series manual motor starters coupled to ABB contactors. These units are designed to be individually locked out. I also have ABB breakers inside the control enclosure that will be locked out.
My question: Is there a insulated type of lock that can be used instead of a metal lock? The motor starters are mounted on DIN rail and are located right next to each other, so there is a concern of accidental contact with energized parts.
Thank you for your help.
Matt Wolf

I'm with the others here. It seems like a bad/dangerous design.
Here, here being the UK, you would almost need an Act of Parliament to be permitted to open a panel that still had live equipment in it!
Ever so slightly more seriously, we always fitted door interlocked isolators or fuse switches, usually ABB, so that you couldn't open the panel door with the power on.
Very seriously, somebody up the chain of command needs to et a professional in to review this design. It it was me, I'd slap a prohibition notice on it in a heartbeat.