Drop Cords?

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Strahan

Strahan

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Location
Watsontown, PA
400.7 Uses permitted (A)(1) pendants, but (B) states each cord shall be equipped with an attachment plug (ok) and shall be energized from a receptacle outlet (???).
210.50(B) states "where flexible cords are permitted to be permanently connected, receptacles shall be permitted to be omitted for such cords." Does this pertain to drop cords and permit me to attach to a box instead of a receptacle?? I'm guessing it does and of course with all the proper strain reliefs. Also does the attachment plug need a scew in hub? I also believe the answer is yes just can't find code section.
This installation is for an industrial setting conveyors an augers frequently interchanged and removed for cleaning and repair. I want to make sure installation meets code. Plus any ideas out there on how to prevent operators from ripping attachment plug off because they fail to unplug it first before removing conveyor? This is a huge issue for us. Other than firing the person who does this any thoughts on how to prevent this?
 
How much of a problem and how much can you spend to fix it?

My suggestion with money not being an issue.

At the bottom end of the cord install Meltric Corp cord connectors with the optional self ejecting mechanism. A small diameter wire rope attaches to the equipment that moves and if it gets pulled it causes the plug to eject.

At the top end use a Kellem grip strain relief attached to the building to support the cord right beside your outlet box. On the outlet box install a straight blade receptacle facing down, install a straight blade plug on the cord. As long as you keep the distance from the support to the box the straight blade will stay put fine. But if the cord gets caught up in equipment, a forklift etc and gets really yanked on it will pull off the grip and drop out of the receptacle without damaging your box and raceways.
 
iwire said:
How much of a problem and how much can you spend to fix it?

My suggestion with money not being an issue.

At the bottom end of the cord install Meltric Corp cord connectors with the optional self ejecting mechanism. A small diameter wire rope attaches to the equipment that moves and if it gets pulled it causes the plug to eject.

At the top end use a Kellem grip strain relief attached to the building to support the cord right beside your outlet box. On the outlet box install a straight blade receptacle facing down, install a straight blade plug on the cord. As long as you keep the distance from the support to the box the straight blade will stay put fine. But if the cord gets caught up in equipment, a forklift etc and gets really yanked on it will pull off the grip and drop out of the receptacle without damaging your box and raceways.
Click to expand...

Ok my fault I wasn't clear. Cord is hard wired to a box at ceiling with appropriate strain relief. Where the problem occurs is down at the attachment plug. Female end on drop cord that plugs into a male plug end from short cord on machine (conveyor, auger). Short cord off of machine that plugs into drop cord. Where this connection exists is where the problem occurs. They fail to unplug machine and end up either ripping female end off of drop cord or the male end off of machine.
 
iwire said:
How much of a problem and how much can you spend to fix it?

My suggestion with money not being an issue.

At the bottom end of the cord install Meltric Corp cord connectors with the optional self ejecting mechanism. A small diameter wire rope attaches to the equipment that moves and if it gets pulled it causes the plug to eject.

At the top end use a Kellem grip strain relief attached to the building to support the cord right beside your outlet box. On the outlet box install a straight blade receptacle facing down, install a straight blade plug on the cord. As long as you keep the distance from the support to the box the straight blade will stay put fine. But if the cord gets caught up in equipment, a forklift etc and gets really yanked on it will pull off the grip and drop out of the receptacle without damaging your box and raceways.
Click to expand...

No receptacle at ceiling. Hard wired.
 
I have a similar problem at a fire/rescue station. Some of the older trucks do not have self ejecting plugs. Once in awhile the cord cap gets ripped off when nobody remembers to jerk it out before taking off.

If you use Iwire's idea the whole drop cord will pop out of the receptacle and there will be no damage. I think its a great idea. I am going to change the drops at the fire house.
 
iwire said:
Yes you could hard wire the top end.

I am just suggesting that if you want to prevent damage to the cover/box/raceways above the equipment you might be better off using a plug and receptacle.
Click to expand...

Thanks! I agree, but after looking at the cable ejector system in your first post I'm starting to think I should take my plug right to the disconnect on the machine and use this "ejection system".
 
jumper said:
I have a similar problem at a fire/rescue station. Some of the older trucks do not have self ejecting plugs. Once in awhile the cord cap gets ripped off when nobody remembers to jerk it out before taking off.

If you use Iwire's idea the whole drop cord will pop out of the receptacle and there will be no damage. I think its a great idea. I am going to change the drops at the fire house.
Click to expand...

Instead you could just wire a straight blade male and female cord cap about 2' from the truck end. This way it pulls apart and can be easily reconnected. This might be what you are suggesting but was not sure.
 
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