Breakaway Devices

[drcampbell]

No, fining employees or trying to make them work overtime without pay is illegal. Did you read to the end of the post I responded to?

I hadn't presumed to make them work overtime without pay. I figured the nuisance & embarrassment value would suffice, especially if the crew meets up socially right after work. As for fining them, check with the lawyer. In at least one state I've worked, it is (was?) legal so long as the employee takes home at least minimum wage at the end of the week. (very common with commissioned sales people who don't sell the minimum and need a "draw" check)

 

[Todd0x1]

What about joining the cord along its length to a wire rope solidly anchored to the machine, say 1/4" diameter, that gets clipped in adjacent to the receptacle, with enough slack for the plug that the wire rope takes all the pulling force and the cord(s) take none? Then the only problem is making sure the wire rope is clipped in when the machine is placed, there's probably a way to force that.

 

[Jraef]

What about joining the cord along its length to a wire rope solidly anchored to the machine, say 1/4" diameter, that gets clipped in adjacent to the receptacle, with enough slack for the plug that the wire rope takes all the pulling force and the cord(s) take none? Then the only problem is making sure the wire rope is clipped in when the machine is placed, there's probably a way to force that.

Same problem as the chain or cable idea; if they are forgetting to unplug the machine first, they will likely forget to clip on the safety cable / chain / rope.

 

[zbang]

It's really a people/training problem. If the employees don't care about the machine, then management needs to get them, somehow, to care. (Or it could be that management doesn't care about the employees and they return the favor.)

Assuming the facility has a safety program, "moving the machine" can become another safety checklist; heck, even add gloves as PPE for it- (Turn off power at main switch, put on gloves, disconnect control lead, disconnect power lead, unlock casters....)

 

[drcampbell]

Same problem ... if they are forgetting to unplug the machine first, they will likely forget to clip on the safety cable ...

Unless you interlock it. (which sounds like more trouble than it's worth)

... disconnect power lead, unlock casters ...

- Install electric wheel brakes so that it won't move while energized.
- Use straight-blade devices mounted on the machine, so that moving the machine and disconnecting the power are the same action.
(like the racks for avionics (aviation electronics))

I still lean toward the human side.
How busy is the facility? Can it tolerate some downtime?
Next time it happens, send the entire crew home for the day. Schedule the repair for the following morning and tell the crew not to show up or punch in until the maintenance person has completed repairs. Maybe the crew as a whole will help the one problem child to be more aware, if properly motivated.

 

[winnie]

Making the 24V control circuits 'break away' is probably trivial. You can probably even find magnetic contacts that will do the job.

For the power circuits...what about some sort of alarm that can only be disabled by plugging in a short break away control connector. Move the machine and the cord gets pulled, and suddenly it starts screaming 'I am a 30 second bomb...I am a 29 second bomb...I am a 28 second bomb...'

The alarm is silent if the main power is unplugged, or if the short break away low voltage cable is plugged in along with the main power.

-Jon

 

[Barbqranch]

How do they move them? Do they slide forklift forks under it, or a pallet jack, or is it on wheels and the push it? Or just drag it across the floor?

 

[PaulMmn]

Making the 24V control circuits 'break away' is probably trivial. You can probably even find magnetic contacts that will do the job.

For the power circuits...what about some sort of alarm that can only be disabled by plugging in a short break away control connector. Move the machine and the cord gets pulled, and suddenly it starts screaming 'I am a 30 second bomb...I am a 29 second bomb...I am a 28 second bomb...'

The alarm is silent if the main power is unplugged, or if the short break away low voltage cable is plugged in along with the main power.

-Jon

Another Heinlein fan, I see!

 

[kwired]

Same problem as the chain or cable idea; if they are forgetting to unplug the machine first, they will likely forget to clip on the safety cable / chain / rope.

Only way this works IMO is if you make that safety chain/cable (rope would need to be conductive in some manner) a part of a low voltage enabling circuit, that machine wont run unless the safety chain/cable is connected. Guess you could make it a mechanical link that actuates a limit switch for an enabling circuit which would mean you likley have to connect the safety chain/cable in a manner that tension is applied so it will actuate the limit switch. But now you will have same problems all over again when something is broken and they find a way to mechanically bypass the limit switch to use the machine.

 

[Meltric_South]

Hello All, as a repetitive at Meltric I can chime in about solutions we offer (although we are definitely not the only one's who offer solutions). For breakaways we offer a self-ejecting style of plug and receptacle (https://www.meltric.com/html/self-ejecting-switch-rated-plugs-receptacles.html) and a device that is connected to the ignition of a vehicle and will eject when the vehicle is turned on (https://www.meltric.com/pdfs/2019-international-catalog/RETTBOX.pdf). For interlocking, we have auxiliary options for each of our devices. For strain relief (which sometimes solves the problem of personnel moving machines around) we have CGB options with wire mesh.

Personally I've seen a million different solutions tried and they all have their quirks in order for them to work properly.

Hope this helps.

 

[cpickett]

Meltric plugs are very nice and they have a combination for anything you can think of, just remember you get what you pay for...

My wife is a large animal vet and the vet box in her truck gets plugged in every night. I started out with a nice cord reel on the ceiling and after it got ripped apart twice I got tired of putting it back together and now she has a cord draped over the driver's side mirror. I joked that I was going to wire an interlock (relay) so that the truck wouldn't start if it was plugged in. I like the idea of brakes that are locked when the machine is plugged in and unlocked when deenergized. Although if the employees truly don't give a you know what, they'll destroy the brakes or figure some other way to move the machine. That is really an issue that management needs to address, but I certainly understand.

 

[Meltric_South]

Likes "just remember you get what you pay for.."

 

[drcampbell]

... I was going to wire an interlock (relay) so that the truck wouldn't start if it was plugged in. ...

Do that, and the day will come when the truck won't start because the interlock relay failed.
With that in mind, I once wired a vehicle so the horn would blow if the starter was engaged while the vehicle was still connected to shore power.

 

[Jon456]

You could go the opposite direction and attach a sturdy chain to the plugs, to take the tension off the cords and reduce the risk that they'll be ripped out.

Don't attach the cable to the plug; the sideways force applied to the plug will damage it as it's pulled out of the wall. Attach the cable to a bracket screwed into a framing member in the wall near the outlet. This is what is done with movable gas appliances in commercial kitchens to prevent the flexible gas lines from being damaged (which could have deadly consequences).