Oh' this is going to take one of my special long answers to explain. It's halfway written and will follow later unless someone else short circuits the explaining before that.
Short answer, look to the
NEC for all your answers. The
neutral is the ribbed side. Classifications of assembly halls or use would be the next thing to look into. A
stage is I believe a class 1 or 2 assembly
hall proper depending upon who runs it and how large it is. (This is all from memory.)
Zip cord was already explained earlier in this posting so I will spare all of you.
After that it's on to SPT-1 or 2
wire verses
lamp cord. Depends upon the
fixture of course but it is only permissible to be used as a direct replacement for
zip cord already on the
fixture - there are heat and amperage issues otherwise in addition to use.
Lamp cord without checking, while similar is not the same. When possible, for
stage use all equipment should be grounded and using proper types, lengths of cable and plugs.
A
sconce is designed to have a bonded
ground. Unless you are using 3-conductor
zip cord, you won't be grounding it which violates it's design use even with any permissible exceptions for
stage applications. Also since the wiring for said wall
fixture will not be seen you should be complying with the
NEC for permissible wires for use on
stage - not just what is cheap and easy. Otherwise why not just string
zip cord all over the
grid? Believe me I have seen it done and also what happens when a clamp is clamped down onto it.
For a
fixture, if it is
zip cord, and you are given permission for it's use by the person liable for it's use and the inspector as it might also be fine, otherwise unless used in special circumstances or specific ones that are approved, follow the code.
Why do people love twist locks so much? 20 years ago they were the hot thing because they would not come apart and that was fealt safe. Now they have their uses but for the most part are not standard practice for just that reason. Unless you are using what would be a L1-15, L1-10 as they might be called or non-nema similar two prong
plug use of a three pin
twist lock plug would be a
clear violation of code even if you yank the
ground pin, just as you can't yank the
U-ground part of a
Edison receptacle. L5-15 or L5-20 plugs are grounded and you are using them on an un-grounded application and
cord. That's a no no in addition to using a other than hard usage cable for the application. This is my interpitation, your person in charged might take a more leaniant stance and interpitation on such things out of necessity. Were it me, I would
plug a
Zip cord I needed to
plug in, into a L5-15 assuming it's your
plug to 5-15
adaptor, than use a polorized 1-15
plug into it. The polorized
plug ensures you won't reverse hot and
neutral - in other words on the
screw shell of a lamp that your fingers can touch as you screw in a light
bulb, it's not
fed by the hot
leg of
power. Thus the reason for noting which part of a
zip cord is hot and which is
neutral also in addition to in following a standard the person that follows you hopefully won't get zapped by a accident you set up.
As for use of
zip cord while working for a event company, it's common in use. As long as you don't
plug in the spool and make a terrific
transformer, for the most part it's safe as long as you don't overload it. The Eagle
Add A Tap system is great. Just bought a hundred of each for a show using them. Expensive somewhat. They are now available in a polorized version which while larger I recommend so you can keep your fixtures safe to use if screw
base. Otherwise without plugs and receptacles that are polorized - having a
neutral prong larger than the hot, all the wiring the
zip cord propery in the world won't help you get lamps pluged in properly. This is especially common when someone cuts off the wide flairing of the
neutral prong from the
fixture's
plug so they can use it on a non-polorized
receptacle. It's also a bad idea to attempt to re-use
zip cord or not pay special attention to it's ends. I have seen sparks in the ceiling
truss from it, question is since the breakers did not trip, just how old or warn out were the breakers, than what did it do to the
wire? That's from exposed ends or ones that when they are cut are too close together than arc. It might just be
zip cord but it's still dangerous without care. The
add a tap system for the most part works well, but in piercing the
jacket it does displace the
wire and often damage it slightly. That damage and those holes in a
wire can be dangerous to handle when the stuff is re-used with new outlets positioned without covering up the holes. One tent company tried to tell me they self seal. That would be a nope. Giving the piercing, and amperage ratings of 18/2 SPT-1, I would not put more than three amps on
zip cord I was using. It's rated for up to 7 amps but would be pushing it especially once
voltage drop figures in.
But
lay a
line of 18/2 SPT-1 along the floor, add a
outlet where you have a
fixture and away you go - great and fast
system. Not overly safe or approved for use in all applications. Also not grounded.
There are other versions of
zip cord on the market. I
stock 12/3
zip cord for convention center use under carpet and with fork trucks running over it. It's also available in a actual convention center
flat cable that's much similar except it does not have solid jackets over it, instead all wires are laid
flat with normal
insulation and a
PVC jacket over them. Largest of this I have made up is a 10/5 or 6/3 version of it. Still
zip cord for all intensive purposes but lots more difficult to put into a
plug.
Flat cable like
zip cord has limited application and permissible use and is acceptable out of necessity. Some cheaper forms of office
cable ramp cable also uses a three
conductor zip cord with the
cable ramp perminantly installed on it.
Zip cord is not hard usage cable rated, it has a lifespan of about 20 years before the rubberized
jacket becomes brittle as well as similar problems when overloaded. It's
voltage rating is also not high enough for low resistance
wire over a long distance at a
stage lighting capacity amperage. I have a piece of
zip cord mounted on my wall of shame in which all you have to do is touch it and it will expose a new section of seriously corroded
wire by way of the
insulation just plain falling off this cable was probably subject to higher than rated amperage and the whole length of
wire went bad. Not safe at all except for low amperages and special use. Tent shows and special events have their own classificaion for what is permissible to be used. You can't be plugging a grounded piece of equipment into the
zip cord iether, though it's frequently done. All it takes is one well placed spilled drink and you have a lawsuit. On
stage you are not even allowed to be using SJ
wire in lengths over 3' and for specified purposes. Far different than rock companies get to use it for due to the fact that
truss is considered adiquate support and protection for it. Now once they
lay anything other than type S such as SOOW-A
wire on the
ground, much less as a
drop line off the or between trusses, it's possible that they are also in violation. This means that the orange zip cords are also against the rules to be used especially on
stage. That's a form of SJ
wire.
Have I used
zip cord on
stage, sure. Given it's approved for special purpose use. It's about senseless to
plug in un-grounded equipment with grounded heavy duty cable. It's better given such equipment is allowed if it were plugged directly into the wall but
zip cord as long as used properly can be used with approval. The
NEC is a set of rules and guielines but there are common sense execptions also.
It has been necessary also to put ungrounded
wire into a
stage pin plug. This gets even more complex because a
stage pin plug can be configured to safely run two pin cable by simply removing the
ground. The problem is that unless really observant it's easy to
plug it in backwards. At times like this I usually cut about 1/3 of the length of the male pin off the
plug leaving a sanded to finished nub stickign out where the
ground was. This confirms that the cable is not grounded as necessary I would interpite, plus helps to ensure the cable will not be plugged in backwards. On the other
hand it's against the
NEC because in doing so it is modifying the
plug. In the case of a
stage pin plug the exception of leaving the
ground in place I would say is permissible and that's about the only cable for me I allow. No grounded
Edison plugs or twist receptacles on circuits that are not grounded. Just one of quarks.
There it's un spell checked but done plus a
bit shorter than it will have been.