“On to your other questions--FWIW and Ship can probably correct me if I am wrong, type
W cable (type W rated at about 2000v if I am correct compared to 600v for type SC), is welding
stock cable-and not neccessarily the best choice for cable to use for
feeder IMO--since type SC cable was made specifically for the Entertainment Industry for this use.” - Wolf
Nope, while type W is a major pain in the rear because it does not twist as well in making the CamLoc connection, it’s still type SC or W for use on
stage by
NEC 2002 as far as I know. Welding cable and type SO for
feeder are the ones not to touch because they when cut or abused given the amperage are really really dangerous. Type W on the other
hand is really really hard to cut much less twist. It’s even more resistant to damage than type SC. Often you will find that in short
tails ends or rack to
rack jumpers, that with a type
W cable, it’s so resistant to cutting that it will unlock itself from the connecter it’s attached to because it’s
jacket is so resistant to twisting much less cuts. That in addition to most type
W cable being past it’s service life is why people don’t want it around. Something about W not wanting to remain in the locked position because in most instances of cable 5' or less it will not stay. But according to the
NEC, for
feeder, it’s still ok.
I love to install ferrules on my
tails. Think about a big ½" wide
bolt clamping down onto a ½" thick
wire that’s within a 3/4"
outlet. What do those strands of
wire want most to do except
escape the
bolt clamping down on them?
Current travels down the circumference of the
wire, any interruption of that flow means more resistance. Ferrules prevent the
wire from falling outside of the direct clamping
power of the screw bearing down on it. In other words, while not a uniform standard for use or required, it’s the method I use when possible. As for pressure, I don’t remember the exact amount, but think it’s similar to that clamping pressure required for CamLocs at 120
Foot Pounds. Go more than that, as studied by EC&M, and there is more resistance thus heat to the
current flow. More than that and there is also resistance. When a
wire is hot, it expands, when cool, it might seem loose but when expanded if over tightened to compensate for a seeming looseness, might also cause resistance in being too tight. 120# is an experience thing to achieve constantly the same on site and without a torque wrench. People without this experience just as someone tightening the belt on a band saw will overcompensate and think it’s better that way.
In other words, I totally agree with Wolf in principal if not application. Without the experience, it does not matter how well you understand the wiring, you can easily do as much damage to the
system as without training and doing it anyway. Not sure how I feel about
current traveling down the rope, it’s non-conductive after all but Wolf’s statement might have merit given nobody uses that method that has experience with live tie ins. Yea, I have someone with a broomstick around and observing me, if working around live
current. I want off the
circuit and don’t care about the disadvantages of a 2x4 in the gut. I have had
EMT conduit actually melt into and bond with the skin in the palm of my
hand while all alone and doing something stupid I tried to fold some wires and shove them into a
conduit in getting the
coupler back together.
Stage lights kind of dimmed and browned out during the live show as noticed in the booth,
circuit breaker never flicked itself off, and it took a extreme contuse effort on that in theory 20 amps of
current passing
thru my body to
release the
conduit I was touching. That was a 20 Amp
circuit - at least in theory given the CB malfunctioned. What would happen should I become a
ground path for a 400 Amp
circuit I would not speculate at. His tips about the
current not traveling by way of the hart are accurate in saving your life and only getting the copper welded to your skin. Given someone pushes you off. That said, when working with live
current, not only am I careful, use 10000V insulated tools around them, but I have someone about that will push me off in addition to keeping the
hand at the side. Or at least not touching something that can conduct. It’s also a question of what boots I wear. Sneakers breathe too much, so do many work boots. I want myself to be other than the path of least resistance.
On cable into a large lug, I just installed some #2 wires into some 2/0
feeder CamLocs on a small AC
Distro I built yesterday. I agree that putting
wire smaller than the lug is a bad thing - even if a
ferrule is used in this case. I filled the CamLoc with some strands of #6
THHN to occupy the space. Folding
feeder wire back on itself is not an option. Good for smaller wires such as
fitting a
Leko’s #16
wire into a 12 ga
ferrule, but it will not work with
feeder cable if for nothing else but the bending radius of the
wire is larger than will fit in the hole. Speaking of trimming or adjusting cable for a hole, don’t
trim the outside of a
wire to fit into a lug, if anything and absolutely necessary,
trim the inside conductors because they are not carrying the main load and there will be at least slightly less resistance. As for being acceptable for
feeder, given the double neural
feeder debate, much less the fact that given a normal lug, it’s normally the same as the hot lugs, I would question what is the
neutral conductor size.
Beyond this all, if you don’t absolutely have experience and training with tie ins - live or not, as with what Wolf says, don’t mess with them. You are not going to suffer from a pay cut and it’s not going to hamper your career. You would not repel down a 80 story building in the middle of a winter storm to focus lights, why would you be tempted to mess with tying in the load which deep down you know only very trained professionals should be trained in. Ya know this, trust in what you know not what your ego says about your ability until you are doing it under the direct supervision of the old man of the theater in training you for it to the best of his abilities. Than even don’t be messing with this stuff unless it’s absolutely your job and you know what the heck you are doing - and I mean that. Wolf’s “uncomfortable - stop and do not do it” is very appropriate on energized and non-panels. I’m personally never comfortable in tapping much less wiring to live panels and I have the training and tools. It’s all a question of being real verses cool. Yea, you can
wire to a
breaker and it’s all good. 20 years later when someone gets killed because you did not have the tension right do you dismiss it as one of your earlier works, or do you sweat the day something like that happens? Wiring to
house electrics is not a tech person’s job. Don’t do it until you are at not only a pro, but I would state an expert and say master
level. I do this stuff as part of my living. I have to given my position at the top, but I would also say no, and easily do this were I not specially trained for it and had I not been studied and practiced enough at the technique to sleep at night. Watch those doing the
tie in to learn from them and ensure they do it properly, but don’t attempt it. Wrong union buddie!
This thing is not an us and them debate, it’s one of experience. Wolf and I do this, but when possible and more dangerous than we are prepared for, we get others and observe them at it. “If you are tying in to a panel using
tails, what would you terminate the
ground and
neutral leeds with so that when you tighten the
neutral or
ground buss screw doen it doesn't completly crush/damage the type W or SC
wire? “ - Reggie, I expect you understand what we say and were just looking for an answer. The answer is ferrules and or copper foil making the wires as if one solid part. That and de-oxidant coating the wires to ensure that any oils in your skin or other contaminants will not cause resistance to the flow of
current. Do I do it all the time, ha. Not as much as my own Old Man of the Theater advises. Gimmie a break, on the other
hand my
wire is wrapped more than his has been over the years. I even bought a
crimp tool specifically for ferrules to smash them tight around the
wire last week.
I don’t do much in the way of shows anymore however. On show electrician’s, they don’t use a rats nest of already clamped
wire for the most part. If the
wire comes out of the
terminal nice looking, and they have a few extra moments of care, such people might
throw a couple layers of courtesy tape around the stripped
wire to ensure it does not get banged up and no longer able to fit into a
terminal. Otherwise, and as I used to do, we are paid enough that when doing the
tie in, we can afford the proper cutting and stripping tools for heavy
gauge wire, and thus strip a fresh end to put into a
terminal. Foil strips would be nice to act as a
ferrule, but at least the goal for the most part is to ensure that all the wires get into the clamp, and there is a distributed pressure on all the
wire.
On school tie ins, yes refuse to do it. Should they try to make you or pend your grade upon it, fear not they are in the wrong unless that specific part is within your training. Heck, when throwing grenades, even I as a person with 6 years in and a Sergeant had someone in the pit with me to if not ensure I threw it, that person would at least kick it into the
safety hole in the pit. What is getting electrocuted any less dangerous than throwing a live
hand grenade? Refuse but do it diplomatically is the wisest course of action. Someone tells me to
tie in, I still ask permission from the
house electrician, and only than if the most qualified, and the person properly trained for it do I attempt it given it’s within my honest ability. Sidestep any part of this and you, your company could kill someone including you, if not do other things bad. You are wise.
Gloves if “Hot Gloves” are smart, A hot mat is also wise, proper tools
etc. but without the proper supervision and training that’s all Nintendo over Artari game systems.
Safety is what you are being supervised and trained in. Good for them if they have all that and proper instruction. Go for it while supervised and trained in it. If you do not feel comfortable, talk and train with the instructor than if better try again. It’s good training if kept within perspective - but only something to do once honestly ready for it.