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X-Real-To: stagecraftlist [at] theatrical.net Received: by prxy.net (CommuniGate Pro PIPE 4.2.10) with PIPE id 35188204; Thu, 21 Sep 2006 03:02:39 -0700 X-Spam-Checker-Version: SpamAssassin 3.1.5 (2006-08-29) on localhost X-Spam-Status: No, score=-1.9 required=5.0 tests=ADVANCE_FEE_1,AWL, NO_RECEIVED,NO_RELAYS autolearn=unavailable version=3.1.5 X-Spam-Level: X-ListServer: CommuniGate Pro LIST 4.2.10 List-Unsubscribe: List-ID: Message-ID: From: "Stagecraft" Sender: "Stagecraft" To: "Stagecraft" Precedence: list Subject: Stagecraft Digest #958 Date: Thu, 21 Sep 2006 03:01:51 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Disposition: inline X-TFF-CGPSA-Version: 1.4 X-prxy-Spam-Filter: Scanned For info, archives & UNSUBSCRIBE, see --------------------------------------------------- Stagecraft Digest, Issue #958 1. Re: Close to home... by Mitch Hefter 2. Re: OT but impressive - bridge collapse by "Zirngibl, Ryan John" 3. Re: Color Coding Fixtures by "Occy" 4. Re: Color Coding Fixtures by "Occy" 5. Re: Color Coding Fixtures by "ladesigners [at] juno.com" 6. Re: Close to home... by "Occy" 7. Re: Close to home... by "Occy" 8. Re: Close to home - followup by "Occy" 9. Re: Driving a truck in Manhattan by "ladesigners [at] juno.com" 10. Re: God of Hell Blue Flashes by "Occy" 11. Re: Driving a truck in Manhattan by CB 12. Re: Color Coding Fixtures by "Bill Nelson" 13. Re: Close to home... by "Bill Nelson" 14. Re: Close to home... by June Abernathy 15. UNSUBSCRIBE by Rian Brooks-Kane *** Please update the subject line of your reply to use the subject *** line of the message you are replying to! Please only reply to *** one message subject in each reply. ---------------------------------------------------------------------- Message-Id: <6.1.0.6.2.20060920212801.01fa5a70 [at] mail.DesignRelief.com> Date: Wed, 20 Sep 2006 21:51:30 -0500 From: Mitch Hefter Subject: Re: Close to home... In-Reply-To: References: On 9/20/2006, Steve Jones wrote: >. . . our 17 year old daughter had been badly shocked by electricity at >the high school theatre where she was working on the drama program. > > I posted the following about 1 year ago. --------- From the USITT Electrical Safety Workshops (derived from multiple sources): It's the current that kills. Higher voltage just makes it easier to get higher currents. The current range of 100 ma to 200 ma is the most lethal, but currents as low as 60 ma can kill. 1 mA -- Threshold of feeling, tingling sensation 5 mA -- Accepted as maximum harmless current 10 - 20 mA -- Beginning of sustained muscular contraction ("Can't let go" current) 100 - 200 mA -- Ventricular fibrillation, fatal if continued; Respiratory function continues 200 mA & Over -- Severe burns; muscle contractions so severe that chest muscles clamp (stop) the heart for the duration of the shock (protecting from Ventricular Fibrillation); breathing is stopped; survival chances are good if First Aid (CPR) is started at once. Typical body resistances: hand to foot (thru the heart) - 500 ohms ear to ear -100 ohms dry skin - 100k - 600k ohms wet skin 1000 ohms Longer contact with the shock current lowers the body's resistance, which increases current flow. Contrary to an earlier posting, Alternating Current (AC) is more dangerous than "pure" Direct Current (DC). It can take between 2 to 4 times the magnitude of DC to produce the same effects as AC. AC induces sweating that lowers skin resistance and causes more severe muscle contractions. 60 Cycle AC which is used in the U.S. and Canada is the most dangerous frequency - it can kill at 25 V. With pure DC (no ripple), the threshold at which Ventricular Fibrillation occurs is fairly constant over time, while this threshold goes down with AC The polarity of DC is a factor, and the threshold of let-go is not really definable with DC under 300 ma since the muscle contractions occurs on make or break. Above 300 ma (DC), let-go may not be possible, and this level usually results in unconsciousness. --End last year's post--- The 3rd degree burn could have been the filament, the current, or both. It is likely the filament punctured the skin, so the skin resistance went very low. 120 volts (the U.S. nominal AC voltage) at 500 ohms (the hand to foot path) = 240 mA . With broken skin, she could have been exposed to that high a current which could do that much burning and definitely cause the muscle contraction. Just be glad it was all in her hand. Any other path could have been much worse. Be aware there could be nerve, muscle, and additional internal tissue damage. The urine may go dark while the system flushes out the damaged tissue. Lot's of fluids the next few days. There will likely be muscle soreness as well. Best wishes on a speedy recovery. . . . ------------------------------------------------------------------ Mitch Hefter Office: Entertainment Technology, a Genlyte Company mhefter [at] genlytecontrols.com +1-214/ 647-7880 x 7967 http://www.etdimming.com :: http://www.vari-lite.com ------------------------------ Subject: RE: OT but impressive - bridge collapse Date: Wed, 20 Sep 2006 22:01:48 -0500 Message-ID: <5CF1C3D95785A143A3E33ACFD864609B06FDD412 [at] PEPSI.uwec.edu> In-Reply-To: From: "Zirngibl, Ryan John" <<>> Me too, I grew up a half hour from there, I swear that construction on 29 has been going on for 15 years now, when will it ever end? Ryan J. Zirngibl =20 ------------------------------ Message-ID: From: "Occy" Cc: alf.sauve [at] mindspring.com (Alf Sauve) References:

Subject: Re: Color Coding Fixtures Date: Wed, 20 Sep 2006 20:42:34 -0700 Glad you colored them something... But kit makes no since to me. ----- Original Message ----- From: "Alf Sauve" To: "Stagecraft" Sent: Wednesday, September 20, 2006 2:55 PM Subject: Re: Color Coding Fixtures > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > I color coded extension cords (multi outlet cords) for orchestra lights > with > this scheme. Something similar might be adaptable to lights. > > Red - Stop Short (a short cord) > Green - Go Long ( a long cord) > Yellow - Caution neither long nor short > > So, > > Red is a short/narrow angle - 19 > Green is a long/wide angle - 36 > Yellow is in-between - 26 > > ----- Original Message ----- > From: "Rob Carovillano" > To: "Stagecraft" > Sent: Wednesday, September 20, 2006 4:03 PM > Subject: Color Coding Fixtures > > > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > I've asked this before, but lost the answer and can't search the archives. > > Is there a standard to use when color coding S4 barrels? > > Rob Carovillano > Technical Director - Bluett Theatre > Saint Joseph's University > rcarovil [at] sju.edu > > > > > > ------------------------------ Message-ID: From: "Occy" References: Subject: Re: Color Coding Fixtures Date: Wed, 20 Sep 2006 20:50:05 -0700 try again ----- Original Message ----- From: "Jeffrey Cebula" > > > One place I worked colored the tubes with the same > > color as ETC uses to ID the lenses < > > > I'm pretty sure it's > > 19: Red > 26:Blue > 36: White > 50: Yellow > > but I could be wrong. > > Also, the place where I used to work put the color > markings under the gel clip on the front of the > barrel. Never understood how that was useful once the > instrument was in the air... > > ...at least I couldn't see the color from 20 feet > below the unit. > > Jeff > > Jeffrey M. Cebula > Scenic and Lighting Design > 610-620-4125 > jeffreymcebula.com > > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > ------------------------------ From: "ladesigners [at] juno.com" Date: Thu, 21 Sep 2006 03:50:25 GMT Subject: Re: Color Coding Fixtures Message-Id: <20060920.205027.15672.465267 [at] webmail31.lax.untd.com> This seems backwards. A Short Throw lens usually has a Wide angle and = a Long Throw lens usually has a Narrow angle. /s/ Richard _____________________________________ > Red is a short/narrow angle - 19 > Green is a long/wide angle - 36 > Yellow is in-between - 26 ________________________________________ > Is there a standard to use when color coding S4 barrels? > Rob Carovillano ------------------------------ Message-ID: From: "Occy" References:

Subject: Re: Close to home... Date: Wed, 20 Sep 2006 20:52:48 -0700 Mitch, How come your always right on this type of thing? ----- Original Message ----- From: "Mitch Hefter" > > > I posted the following about 1 year ago. > --------- > From the USITT Electrical Safety Workshops (derived from multiple > sources): > > It's the current that kills. Higher voltage just makes it easier to get > higher currents. > > The current range of 100 ma to 200 ma is the most lethal, but currents as > low as 60 ma can kill. > > 1 mA -- Threshold of feeling, tingling sensation > 5 mA -- Accepted as maximum harmless current > 10 - 20 mA -- Beginning of sustained muscular contraction ("Can't let > go" > current) > 100 - 200 mA -- Ventricular fibrillation, fatal if continued; > Respiratory > function continues > 200 mA & Over -- Severe burns; muscle contractions so severe that chest > muscles clamp (stop) the heart for the duration of the shock (protecting > from Ventricular Fibrillation); breathing is stopped; survival chances are > good if First Aid (CPR) is started at once. > > Typical body resistances: > hand to foot (thru the heart) - 500 ohms > ear to ear -100 ohms > dry skin - 100k - 600k ohms > wet skin 1000 ohms > > Longer contact with the shock current lowers the body's resistance, which > increases current flow. > > Contrary to an earlier posting, Alternating Current (AC) is more dangerous > than "pure" Direct Current (DC). > It can take between 2 to 4 times the magnitude of DC to produce the same > effects as AC. AC induces sweating that lowers skin resistance and causes > more severe muscle contractions. 60 Cycle AC which is used in the U.S. > and > Canada is the most dangerous frequency - it can kill at 25 V. > > With pure DC (no ripple), the threshold at which Ventricular Fibrillation > occurs is fairly constant over time, while this threshold goes down with > AC > > The polarity of DC is a factor, and the threshold of let-go is not really > definable with DC under 300 ma since the muscle contractions occurs on > make > or break. > > Above 300 ma (DC), let-go may not be possible, and this level usually > results in unconsciousness. > --End last year's post--- > > The 3rd degree burn could have been the filament, the current, or both. > It > is likely the filament punctured the skin, so the skin resistance went > very > low. 120 volts (the U.S. nominal AC voltage) at 500 ohms (the hand to > foot > path) = 240 mA . With broken skin, she could have been exposed to that > high a current which could do that much burning and definitely cause the > muscle contraction. Just be glad it was all in her hand. Any other path > could have been much worse. > > Be aware there could be nerve, muscle, and additional internal tissue > damage. The urine may go dark while the system flushes out the damaged > tissue. Lot's of fluids the next few days. There will likely be muscle > soreness as well. > > Best wishes on a speedy recovery. > > . . . > ------------------------------------------------------------------ > Mitch Hefter > > Office: Entertainment Technology, a Genlyte Company > mhefter [at] genlytecontrols.com +1-214/ 647-7880 x 7967 > http://www.etdimming.com :: http://www.vari-lite.com > > > ------------------------------ Message-ID: From: "Occy" References: Subject: Re: Close to home... Date: Wed, 20 Sep 2006 21:08:40 -0700 Wrong we have enough things to fix much less a cheap ass micro switch on anything less than 5k and down except, arc lights which brings a whole new world too life. ----- Original Message ----- From: "Paul Schreiner" --------------------------------------------------- First things first...good to hear she's okay. Also good to hear that she understood where she went wrong and 'fessed up. But it is another reason to push manufacturers to follow Selecon's lead and install microswitches that cut mains power to the socket when the lamp base is removed... ------------------------------ Message-ID: From: "Occy" References: Subject: Re: Close to home - followup Date: Wed, 20 Sep 2006 21:13:09 -0700 Sorry but out of my budget, but will be at LDI. ----- Original Message ----- From: To: "Stagecraft" Sent: Wednesday, September 20, 2006 7:29 PM Subject: Re: Close to home - followup > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > steve.jones writes: > >There was one 1/4" wire that was left exposed inside the base - but it > >was sticking straight up from one post and not touching the walls of the > >base - so no completed circuit. > and > >As she squeezed the base, .... > >As she did, the sides of the base came in contact with the 1/4" wire > >that was still live, causing the circuit to complete. > and > >This would be consistent with the burn marks location on her > >hand. In addition to electrical flow, I am sure the base itself heated > >up > >and added to the burn as she was "attached" between 15-30 seconds. > > Steve, > > Your follow-up report is excellent. Thank you for providing the details. > > However, in your comments I snipped above, I think you have drawn an > incorrect conclusion. > It would not be necessary for the base to contact the wire piece and if it > had there would have been an arc flash (hot to ground) that might have > tripped > the breaker. > > Rather, her hand provided the circuit path between the hot lead and > ground. > Wet skin can have a resistance on the order of 1000 Ohms. Applying Ohms > Law: 120V / 1000 Ohms = 120 mA of current flowing. While that may not > sound > like very much it is sufficient to cause extreme pain, severe muscular > contractions, and respiratory arrest. Death is possible. > > The duration of the exposure likely lead to the burns. Current flowing > through a resistance creates heat. The heating (and initial skin damage) > would > lead to decreasing resistance and hence an increase in current flow which > would increase the heating effects. Vicious cycle but never reaching > sufficient > current flow to trip a 20A breaker (typical on dimmer circuits). > > Even if she was touching other metal components, the path through her hand > between the base and the wire would have been the path of least resistance > and > as such, most of the current would flow in that path. > > Since the entry and exit points would have been very close together, it is > possible that the current might not have affected the rest of her body. > But > by all means, don't take a chance. Have her completed checked by a > medical > professional WHO HAS EXPERIENCE with electrical shock injury. Often the > internal damage is not obvious and can later lead to serious > consequences. > > A coworker was bitten last year by a power cord to an amp rack he was > testing. It did not seem like much at the time. He went to the > emergency room > (company policy) and they said he was fine. But, for days he was feeling > weak > and had stomach pains. He returned to the ER several times and each time > they > said it was nothing. Until the time he was there and a doctor "happened" > by > who had experience with electrical injuries. He immediately recognized > the > problem and put my friend into surgery to repair intestinal bleeding. It > is a > miracle that he did not die from blood loss earlier. > > Steve Vanciel > Orlando, FL > > P.S. For a fuller explanation of electrical hazards and shock, I would > invite all to attend the Electrical Power class several of us are > presenting at > LDI next month. Also, refer to NFPA 70E and OSHA 29 CFR 1910. > ------------------------------ From: "ladesigners [at] juno.com" Date: Thu, 21 Sep 2006 04:12:37 GMT Subject: Re: Driving a truck in Manhattan Message-Id: <20060920.211248.15672.465342 [at] webmail31.lax.untd.com> Does the information have to be truthful? It appears that NYPD uses = more than it's share of undercover vehicles, many of them taxis... = /s/ Richard ________________________________________ It's true. Commercial vehicles in NYC must have their name address = and phone number on the side of the cab. And they have strict rules = as to the type of letters and size, etc. magnetic signs are not = permitted. The rules have been around for some time but they've been = enforcing them more since 9/11. And no, they do not care where you = come from. If you come into the city you need the signage. They have their reasons for this kind of stuff. Think about the = number of trucks coming into NYC every day. Now think about the big = bull's eye that NYC represents. = Bill S. ------------------------------ Message-ID: From: "Occy" References:

Subject: Re: God of Hell Blue Flashes Date: Wed, 20 Sep 2006 21:23:22 -0700 Having a Jacob in my garage and it takes 35k volts to make it work right. Even talent can be a pain in the bum, I wouldn't even put talent in that distress. ----- Original Message ----- From: "Bill Nelson" > --------------------------------------------------- > > >> Just trying to keep things lively, No way would I put a jacob's ladder > >> anywhere near an actor, (even if they deserved it) > > > > If a Jacob's ladder is used with a dead mans handle controlled by a > > technician assigned solely to that task, then it's a safe effect. > > Not necessarily, they produce both ozone and NO2. NO2 is not an oxide of > nitrogen that you want to breath at all and more than very low > concentrations of ozone are also harmful. > > Bill > > ------------------------------ Message-Id: <3.0.6.32.20060920213205.00d1de68 [at] pop.west.cox.net> Date: Wed, 20 Sep 2006 21:32:05 From: CB Subject: Re: Driving a truck in Manhattan >Speaking as someone that drives in the city on a very regular basis I just >gotta say...You're Kidding, right? Cars get out of the way? For trucks? >Not a chance. Cars do not stop for anyone at any time Paint the thing yellow. My favorite vehicle in LA or NYC is a 24' yellow box truck. Simply follow the 'nicer car rule' when you want to change lanes. San Fran is a whole different story altogether. I did have the satisfaction of whistling out the cab to a guy that had parked in the spots that SFPD had blocked off and telling him (once I got him off his cell phone) that he had to move 'cause he was in my spot. The look of incredulity was only surpassed by my return look of the great satisfaction I was gonna get crushing the towncar like a beercan. Besides, if you're nice to the Teamsters in Manhattan, they'll tell you where to park free. Chris "Chris" Babbie Location Sound MON AZ Delete key training and post trimming done by appointment. Rates negotiable, will trade for typing lessons/ADD treatment... ------------------------------ Message-ID: <1082.205.215.255.53.1158816317.squirrel [at] webmail.peak.org> In-Reply-To: References:

Date: Wed, 20 Sep 2006 22:25:17 -0700 (PDT) Subject: Re: Color Coding Fixtures From: "Bill Nelson" I like to use either the rainbow progression (resistor color code) or alphabetical sequence. ETC uses the following for their identification dots on their lenses: red - 19 degree black - 26 degree white - 36 degree yellow - 50 degree I don't like it because it is not a logical progression. And black should not be used if you have black lens assemblies. Swap the red and black - you would have an alphabetic progression, which would be easy to remember. One rainbow progression would be: Red - 19 degree (long throw - similar to long wavelength of light) Yellow - 26 degree Green - 36 degree Blue - 50 degree Bill ------------------------------ Message-ID: <1109.205.215.255.53.1158817946.squirrel [at] webmail.peak.org> In-Reply-To: References:

Date: Wed, 20 Sep 2006 22:52:26 -0700 (PDT) Subject: Re: Close to home... From: "Bill Nelson" > Nice idea. I wish Selecon had implemented it a little better. Those > damn switches account for a lot of 'bad' bulbs being changed in them. > The switches move around a bit and then don't close reliably. Yep. A poor and cheap implementation of a possibly good idea. On the other hand, if a person follows proper procedure, there is absolutely no need for such switches. Bill ------------------------------ Message-ID: <20060921062029.38539.qmail [at] web34501.mail.mud.yahoo.com> Date: Wed, 20 Sep 2006 23:20:29 -0700 (PDT) From: June Abernathy Subject: Re: Close to home... >He also said that their "in house" >electrician said you can't really remove those bi->post lamps - you just "hafta grab 'em w/ pliers and >pull 'em out and they break 'em off most >of the time and then dig out the base"). This, to me, is a real issue that you discovered. This guy obviously doesn't know anything about theatrical lighting fixtures. I'm concerned about what his function is in relation to them and to the students. Does he customarily change lamps when the students aren't doing so? Does he instruct students in maintenance and/or other electrical issues? Because if the answer is even sometimes yes, he needs training, at the very least. You don't want the kids digging into lamp bases with pliers, I don't think, unless there is some way to ENSURE that they are disconnected from power first. (And in any case, how about grabbing the BASE with the pliers, rather than the glass envelope, eh Mongo?) In an educational setting, I would likely have a rule that a lamp that needs more than your hands to dislodge it, or whose envelope has broken, must be brought to floor for surgery. The other point of concern is that the unit was apparently not only still plugged in, but, as you say "on". Of course she should have unplugged, but who was in charge of bringing channels up and such? Because even if she had miraculously managed incident free extraction, the minute she put a new lamp in, she would have gotten an unwelcome surprise at the least and possibly eye damage at the worst. A wary electrician such as your daughter has now become learns early on to unplug for these reasons as well as the more flammable ones, but that channel should have been, at the very least, "off". It's not safe to work on a lamp that is plugged in even with the channel off, but it's safer than on, for sure. Your ambulance concerns are probably valid. It might be instructive to find out what the school considers proper procedures to be in an emergency situation. In this litigious society, it's hard to know what the right thing is. You are angry that she wasn't put in an ambulance right away. Another parent might be angry if their child was. Ambulances are suprisingly expensive, too - in this case, who ultimately incurred that expense? You? Another parent might be angry if such an expense was thrust on them without their say so. The school? They might have a set of criteria for what must happen before a school employee calls for (and therefore incurs the expense of) an ambulance. Worth checking out. Maybe they have a "YES! Put my kid in an ambulance and call me later! And it's On ME!" form that you can fill out for them to have on file. (Is there such a thing? Wouldn't it be cool?) Anyway, glad she's OK, and learned a thing or two. Hope the principal doesn't take it out on the department. June Abernathy IATSE #321 (Tampa, FL) FOH Electrician The Lion King National Tour (Gazelle) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------ Message-ID: <45124AD9.2020508 [at] rianbk.com> Date: Thu, 21 Sep 2006 18:18:33 +1000 From: Rian Brooks-Kane Subject: UNSUBSCRIBE References: In-Reply-To: ------------------------------ End of Stagecraft Digest #958 *****************************