Post by: Lee Patzius on August 07, 2007, 04:26:39 AM
2) There's a 240 volt, 3 phase, sound and lighting system, mounted on a trailer, and it's transferred to a new location.
It has been running perfectly all season, on 5 wire systems. Nothing on the trailer has been changed, not one wire. So, in proceeding to the new location, they come across a 240 volt 4 wire 3 phase system. The handy man adapts from the original 5 wire 3 phase plug to the new venue’s 4 wire three phase system. He hooks in hots to the venues hots, just as you would expect, and even puts all the grounds, on grounds. His buddy pats him on the back and says "Job well done. Lets fire’er up!"
Next thing you know a bunch of 120 volt stuff blows up. Why did all those 120 volt devices blow up? What was not done to the trailer, that the 5 wire system didn't need?
Hint: This question has changed from the original, to simplify it.
3) (Super easy question…) You notice when the kick drum hits, and half you stuff goes dim, the other half goes bright. But then sometimes it’s OK. But then you notice other stuff goes bright too, when certain lights are dimly illuminated, and you power strip starts smoking. What’s happening?
4) You hook up a bunch of equipment in a bar, and plug it in without a distro, and notice your subs traveling in and out rather slowly, and you hear some hum. WTF? What’s going on? How do you fix it without a distro?
5) You hook into a bar system, with a perfectly wired distro, and perfectly wired PA system. There is NOT one electrical wire misplaced. The band and backline is NOT here yet. Yet you hear hum. It didn't do this before, but this time the PA setup placement is a little different. What’s the most likely culprit? How do you troubleshoot it?
6) A generator just barely shows up in time for a pool party, in the back of a pickup truck with a bed liner. You run over from the swimming pool and ain’t got time to remove it, nor ground it, heck, you don't even have time to put on your shoes!
So you quickly check fuel and start it up, to see if it works. You find that the generator is in excellent shape, and is running full RPM. So you proceed with testing it to see if it puts out full voltage and frequency, while barefoot, and standing in soaking wet grass from the pool. During the test, you slip and touch a hot phase with you bare hand. How much current does it take to kill you? Do you die?
7) You plug an empty power strip into a GFCI, and the GFCI trips. You ohm out the power strip, and the wiring tests good. So you plug it back in again, and the GFCI trips again. So you bypass the GFCI, and proceed with plugging backline gear into the power strip anyway. Next thing you notice, you hear a hum, and the bass player is getting shocked. Why? What was your 1st mistake? 2nd mistake?
What is Watts RMS? 9) You plug a 2 wire vintage guitar amp into an outlet, and the guitar player gets shocked with 60 volts AC on his lips. Why?
10) (Very easy) You measure 12 volts DC between two wires, so you hook up a light bulb and it don’t light. So you measure across the light bulb, while connected, and it reads 0.00 volts. What happened? What’s bad?
11) You hook up your 12 Volt car stereo, and a bunch of other 12 volt peripheral devices. With lots of killer lights, flashing subs, capacitors with bright blue voltage indicators, and you even go as far as using tricked out fuse holders with led fault indicators, color coded monster cable, overpriced gold plated connectors… The WORKS! So, a week later, you plug in your miniature MP3 player to your fused 12 volt tap, and hook it into your system, and play your favorite song. You pump it up, and the next thing you know, your subs sound like shit. So you turn the MP3 down, and everything is fine. You turn off your system, go to the trunk, and check all the fuses with a voltmeter. You get 12 volts out of every one of them. Go back into your car, everything else sounds good, but your MP3 player sounds like shit when you turn it up. WTF?
12) You hooked up your 30 amp cheater plug to two parallel 20 amp circuits, and noticed soon after, that a metal conduit run leading to your system turns red hot, right above the dance floor. Everything appears to be working fine, so of course you just keep plugging away, until it drips molten metal. What did you do wrong?
13) Easy Bonus question... I measure 100 amps on each hot leg of a 240/120 volt single phase panel. What's the total amps to the load?
HINT: The handy man splits his loads evenly across the breaker panel. He hooks up six 30 amp cheater adapters, across 12 parallel breakers, going to six 30 amp sub amplifiers, and four steady 5 amp loads (that totals up to "100 amps worth" on each leg) and is running at full voltage (240V leg to leg and 120 volts leg to ground) while injecting a steady 80 Hz sine wave signal within the sub band.
That's all for now. These are VERY easy questions.
Edit: #1) Added bonus Q and got your name right.
#2) Added hints for clarification.
Post by: Tim McCulloch on August 07, 2007, 10:58:31 AM
Thanks for the test. I'm gonna print it out for a couple of other 'know it all' types around my town.
My personal guess is that Haywood Yabuzzoff can't answer more than 2 of your questions correctly, but WONT attempt to answer any of them. He will then resort to bullshit passive-agressive ad hominem attacks.
Just my prediction.
Have fun!
Tim Mc
Post by: Tom faderjockey Brandis on August 07, 2007, 11:45:43 AM
I've been hit with 220 because of stupidity. I'm lucky to still be here. I know time and time again we reiterate to people that if you don't know what you are doing, call someone who does. Bottom line: Electricity KILLS!!!! I surely don't want to be responsible injuring or killing someone.
I little bit of knowledge can be a dangerous thing.
Tom in Baltimore
Post by: Rick Stansby on August 07, 2007, 12:06:21 PM
| Lee Patzius wrote on Tue, 07 August 2007 09:26 |
13) Easy Bonus question... I measure 100 amps on each hot leg of a 240/120 volt single phase panel. What's the total amps to the load? |
That question can't be answered without knowing the voltage the load is running at. I think I'll call a qualified electrician.
Post by: Bob Dore on August 07, 2007, 12:38:22 PM
Are you going to post the correct answers in due course so I can check?
Bob.
Post by: Lee Patzius on August 07, 2007, 01:47:01 PM
I added a few hints for clarification, especially on the trailer setup, to avoid it from being a trick question, and to reduce the number of right answers.
I knew where I was going, but forgot to add that little piece of information... It was 3 some odd in the morning after an Ozzfest concert, in brutal heat!
Hey Rick... I didn't need to add the voltage hint, but I gave the question more details, to remove all doubt.
There may be other hints added if I feel these are tricked up in any way.
To all others, I will post answers very soon. Sorry, I haven't typed them up yet!
And Chris Haywood, you may ask as many questions as you like, and I'll give you as many hints as you need, and I won't even count it against you (or anyone else). Give it shot!
Post by: Jeff Babcock on August 07, 2007, 04:00:53 PM
Post by: Scott Smith on August 07, 2007, 04:38:35 PM
Post by: dave stojan on August 07, 2007, 04:38:49 PM
| Rick Stansby wrote on Tue, 07 August 2007 17:06 | ||
Is anybody allowed to answer these question?
That question can't be answered without knowing the voltage the load is running at. I think I'll call a qualified electrician. |
Since he only refers to one "load" and 100 amps on each hot leg of single phase service the answer is easy and obvious (100). For those in doubt the call to a qualified electrician is in order.
BTW good quiz Lee!
Post by: Jeff Babcock on August 07, 2007, 04:47:49 PM
Chris????
Post by: Ryan Lantzy on August 07, 2007, 05:21:28 PM