I'd bet the difference between 10/3 SO and 4/3 SO would be nearly 2.00 pr ft. difference.
Not that it matters as far as having to abide by the code.
JAP>
plug
- Thread starter rswolff001
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I'd bet the difference between 10/3 SO and 4/3 SO would be nearly 2.00 pr ft. difference.
Not that it matters as far as having to abide by the code.
JAP>
rswolff001
Member
update
update
yes, I figured that changing the plug was not legal regardless of whats been done in past.
As far as upping the cord.....that was my first choice however this is a relatively small skid (5'x5'x5' or somewhere around that)....it has piping all around it....the cord actually comes out of the bottom of the controls enclosure .....somewhere in the middle of the skid.......surrounded by piping, valves and framework.......did I happen to mention its a Pharmaceutical piece of equipment and everything is stainless? There really is no easy access to the strain relief.....from either the outside of the enclosure or the inside....cramped doesn't actually do it justice.....and once inside the enclosure it (the cord) snakes behind some wireway and components, around the enclosure until it lands on a small rotary disconnect.....its not rated for 60a either.....so I'd probably need to swap that out also.....and lets not forget the wiring from the disconnect to the first current limiting device.....that doesn't meet 60a distribution requirements either. And thats bundled inside the wireway and also snakes around the enclosure. (don't ask me why, I didn't build the thing)......so it gets a bit involved to swap the cable.
My answer was to add a small enclosure with a MCCB and an integral handle and disconnect, rated at 30a to the machine.....I'd wire 4/4 cord from the supply side of the MCCB to a 60a plug that matches the wall receptacle.....then I'd wire the existing cord already installed to the load side of the MCCB. Thats a bit more than $300 for 15' of SO Cord and a hubbel plug.
And did I forget to mention that they have a dozen or so other pieces of equipment where someone simply swapped the plug.....I've already indicated to my customer that I don't believe they don't meet code.
thanks, bob :roll:
update
yes, I figured that changing the plug was not legal regardless of whats been done in past.
As far as upping the cord.....that was my first choice however this is a relatively small skid (5'x5'x5' or somewhere around that)....it has piping all around it....the cord actually comes out of the bottom of the controls enclosure .....somewhere in the middle of the skid.......surrounded by piping, valves and framework.......did I happen to mention its a Pharmaceutical piece of equipment and everything is stainless? There really is no easy access to the strain relief.....from either the outside of the enclosure or the inside....cramped doesn't actually do it justice.....and once inside the enclosure it (the cord) snakes behind some wireway and components, around the enclosure until it lands on a small rotary disconnect.....its not rated for 60a either.....so I'd probably need to swap that out also.....and lets not forget the wiring from the disconnect to the first current limiting device.....that doesn't meet 60a distribution requirements either. And thats bundled inside the wireway and also snakes around the enclosure. (don't ask me why, I didn't build the thing)......so it gets a bit involved to swap the cable.
My answer was to add a small enclosure with a MCCB and an integral handle and disconnect, rated at 30a to the machine.....I'd wire 4/4 cord from the supply side of the MCCB to a 60a plug that matches the wall receptacle.....then I'd wire the existing cord already installed to the load side of the MCCB. Thats a bit more than $300 for 15' of SO Cord and a hubbel plug.
And did I forget to mention that they have a dozen or so other pieces of equipment where someone simply swapped the plug.....I've already indicated to my customer that I don't believe they don't meet code.
thanks, bob :roll:
Sounds to me like the 60 amp outlet on the wall is where the problem is.
Not the 30 amp machine itself.
I think I'd be looking at putting a 30a male cap on the cord and a 30a outlet on the wall and be done with it.
JAP>
- Occupation
- Licensed Electrician
So you've got a Frankenstein machine from Bulgaria and you want the NEC to be a substitute for manufacturer specs, or guidelines. That's not what the NEC is for. The NEC tell us what to do to safely bring power up to the spot on the wall where the machine plugs in.
Personally, I don't see a problem with using the smaller cord. Smaller cords are used on bigger circuits all the time and the way you describe it the machine is going to protect the cord from overload so the 60A breaker is nothing more than short circuit ground fault protection. That's the same thing we do with motor circuits and breakers all the time.
rswolff001
Member
update
update
that might work....however some of the equipment is rated over 30a (possibly up to 60a).....and I don't believe they meet the 80% rating the NEC has for portable machines using flexible cabling.
heck....if this was simply change a plug (or receptacle) I'd be long done. If they had done the initial power distribution correct the first time (it was designed by a licensed PE) they wouldn't have this problem. But like anything else, the wrong questions were asked, so the wrong answers were given.
thanks, bob
update
that might work....however some of the equipment is rated over 30a (possibly up to 60a).....and I don't believe they meet the 80% rating the NEC has for portable machines using flexible cabling.
heck....if this was simply change a plug (or receptacle) I'd be long done. If they had done the initial power distribution correct the first time (it was designed by a licensed PE) they wouldn't have this problem. But like anything else, the wrong questions were asked, so the wrong answers were given.
thanks, bob
- Occupation
- Licensed Electrician
rswolff001
Member
update
update
and lets try this again......
I agree.... this is done all the time for some things.....and possibly its wrong.....I can find nothing in the code that says its allowable, and several things that appear to indicate its not. So if I needed to make an argument, I'd be safe not to allow it and be able to support my claim. Saying we do this all the time is fine as long as there is some supporting evidence......which apparently no one can do.
So if you can point to something in the code that indicates in some fashion this would be allowable I'll be more than happy.
thanks, bob :huh:
update
and lets try this again......
I agree.... this is done all the time for some things.....and possibly its wrong.....I can find nothing in the code that says its allowable, and several things that appear to indicate its not. So if I needed to make an argument, I'd be safe not to allow it and be able to support my claim. Saying we do this all the time is fine as long as there is some supporting evidence......which apparently no one can do.
So if you can point to something in the code that indicates in some fashion this would be allowable I'll be more than happy.
thanks, bob :huh:
- Occupation
- Licensed Electrician
You are asking the NEC for something that it's not written for. The NEC is a safety standard for premisis wiring, it's not a guideline or standard for manufactured equipment.
Adamjamma
Senior Member
- Location
- Jamaica and london
I am not familiar with all the equipment available, but how do they build the outlets for the RV parks? The ones with the two different plugs but only one feed line? Is there a fuse in the outlet? Could the same not be done at the wall outlets for this... a normal 60 amp outlet and feeding through pullout fuses a thirty amp outlet... kind of like the fused spurs here in the UK? Then you would have both plug types at the wLl but still only have the 60 amp breaker...
side note edit... here in UK when we need to fuse something like a five amp light, we do it in the cord... everything up to thirteen amps uses one plug but many things are fused for less amps...plug will actually handle up to 40 amps plus but only officially rated for 13 amps
side note edit... here in UK when we need to fuse something like a five amp light, we do it in the cord... everything up to thirteen amps uses one plug but many things are fused for less amps...plug will actually handle up to 40 amps plus but only officially rated for 13 amps
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
This may not be relevant to OP situation
Because is a specific exception to general rules and has to do with "Household Ranges and Cooking Appliances"
2011 NEC 210.19(3) Exception No.1
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
OCPD is about current, not voltage. I didn't read the whole thread, so I apologize if this is a redundant post.
rswolff001
Member
update
update
this irked me so my reply is directly to ActionDave.
First off, I doubt its a Frankenstein machine. Second, I wasn't looking for the NEC to replace any manufacturers specifications. I was simply asking a straight code specific question. And I doubt that your response would apply if the manufacturer was doing something YOU knew didn't meet code, or wasn't safe. As a case in point, if you were asked (normally by the end user not the manufacturer) to wire a motor in a Classified area, and the manufacturer said you don't need to use seals, would you do so and simply shrug it off. I'll make it easier, the motor goes from their control panel in a non classified area, into the classified area. And the motor isn't XP either. (the mfg tells you they've never had a machine issue) According to you, your obligation ends at the power feed to the control panel. Everything else is up to the mfg of the equipment. I'll remind you (as some reading this may not be aware) that as a licensed electrician, and working for the end user, you have a legal obligation not to do whats potentially wrong, and possibly dangerous. I hold off on telling you, you might also have a responsibility for not allowing it to be installed in that fashion by anyone.
I am aware that if I drop the feed to 30a I'm ok. I'm aware that if I put in a sub-panel I'd be ok. The mfg put a 30a plug on the machine so apparently they wanted a 30a feed circuit. Still didn't really answer my question would it be acceptable practice to put a 60a plug on the machine. From the responses I got, as well as specific issues in the NEC code, I would make an acceptable argument that its not. I found no one that could make any code based argument that it would be.
thanks, bob:blink:
update
this irked me so my reply is directly to ActionDave.
First off, I doubt its a Frankenstein machine. Second, I wasn't looking for the NEC to replace any manufacturers specifications. I was simply asking a straight code specific question. And I doubt that your response would apply if the manufacturer was doing something YOU knew didn't meet code, or wasn't safe. As a case in point, if you were asked (normally by the end user not the manufacturer) to wire a motor in a Classified area, and the manufacturer said you don't need to use seals, would you do so and simply shrug it off. I'll make it easier, the motor goes from their control panel in a non classified area, into the classified area. And the motor isn't XP either. (the mfg tells you they've never had a machine issue) According to you, your obligation ends at the power feed to the control panel. Everything else is up to the mfg of the equipment. I'll remind you (as some reading this may not be aware) that as a licensed electrician, and working for the end user, you have a legal obligation not to do whats potentially wrong, and possibly dangerous. I hold off on telling you, you might also have a responsibility for not allowing it to be installed in that fashion by anyone.
I am aware that if I drop the feed to 30a I'm ok. I'm aware that if I put in a sub-panel I'd be ok. The mfg put a 30a plug on the machine so apparently they wanted a 30a feed circuit. Still didn't really answer my question would it be acceptable practice to put a 60a plug on the machine. From the responses I got, as well as specific issues in the NEC code, I would make an acceptable argument that its not. I found no one that could make any code based argument that it would be.
thanks, bob:blink:
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Would 240.3 supercede 240.5 and direct you to other articles with certain applications? If the supplied load is motor(s) then you would go to art 430.
- Occupation
- Licensed Electrician
Sorry you got irked. It wasn't my intention to be irksome. It was meant to give some perspective that the NEC is a resource but it's not all encompassing. I am irked that every three years I have to put up with a bunch of code changes that don't have anything to do with the original scope of the NEC.
It was a whimsical description, not a dismissive one. It was based on your posts that basically said it's a complex machine from overseas.
Manufacturers get away with all kinds of stuff that I can't. I can't put sixteen gauge wire on a twenty amp circuit, but I can wire up a light fixture with those same little wires to my twelve gauge wires.
That's not it at all. If I place a plug on a wall and it's up to code I'm done. What somebody decides to plug into it is their business. Case in point, go down to any RV store and you will find a wall full of adapters that will help you plug any combination of amp and volt rated cords into every standard recpt.
110(3)(B) is the closest thing you'll find for an answer.
Make the call. I won't argue with you. I make decisions everyday based on code, my gut, advice from others, and my meager understanding of electricity and physics. The NEC doesn't tell me how to handle every detail, it shouldn't have to. At the end of it all it's my decision and I stand behind each one of them.
I'm quite ADD so I'll admit I skimmed though most of what you wrote. What I gathered is that you have a machine that is fused at 30A so it can never draw more than that. The 60A breaker is nothing more than short circuit protection, which is going to be 60000A for a split second so it really doesn't matter what size it is. This is done all the time with motors as long as I have been alive and them some and it still freaks people out today.
As far as the NEC goes, you can put the 60A plug on a 30A breaker and walk away. There is no need to add anything.
It's hard to find seasoned folks on this forum that would recommend taking an already code compliant piece of equipment, and, altering it to where they'd have to find a code based rule to defend their reasoning for doing so.
Most of us would change the outlet.
Not the machine.
JAP>
Andy Delle
Senior Member
- Location
- Los Angeles CA
Consider this:
Consider this:
A table lamp has an 18ga cord. That's typically rated for 10amps max. Yet you can plug it into a 20a circuit. That's a 50% overage just as is the 30amp cord into a 60a circuit.
What's the difference code wise because the lamp situation is perfectly within the NEC.
And let's face it. All this concern over "partial shorts". What's that anyway? The machine is said to have it's own OCPD. That will cover internal shorts and overloads. If a forklift crushes the 30a cord, the 60a breaker will still trip quite quickly.
Unless this is an AHJ issue or liability concern, I really don't see a problem here.
Consider this:
A table lamp has an 18ga cord. That's typically rated for 10amps max. Yet you can plug it into a 20a circuit. That's a 50% overage just as is the 30amp cord into a 60a circuit.
What's the difference code wise because the lamp situation is perfectly within the NEC.
And let's face it. All this concern over "partial shorts". What's that anyway? The machine is said to have it's own OCPD. That will cover internal shorts and overloads. If a forklift crushes the 30a cord, the 60a breaker will still trip quite quickly.
Unless this is an AHJ issue or liability concern, I really don't see a problem here.
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