Skip to comments.
Question about electrical supply to overhead ceiling box
Posted on 08/18/2006 3:36:00 AM PDT by rudy45
I am working on an overhead ceiling fan, which is wired to an electrical box in the ceiling. That box and fan are powered by a wall switch. Also, I have located the circuit breaker that controls that box.
Instead of turning off the circuit breaker, why couldn't I simply turn off the wall switch, if I want to avoid the chance of electrical shock? Wouldn't turning off the switch prevent current from getting to the ceiling box? Or is there still a danger of shock, even though the switch is off?
I DO intend to turn off the breaker, but still am curious. Thanks.
TOPICS: Hobbies; Miscellaneous
KEYWORDS: electricity; homerepair
Navigation: use the links below to view more comments.
first 1-20, 21-29 next last
1
posted on
08/18/2006 3:36:01 AM PDT
by
rudy45
To: rudy45
If there is a single switch, you are OK. Kill the breaker anyway, though.
2
posted on
08/18/2006 3:38:44 AM PDT
by
Toby06
(True conservatives vote based on their values, not for parties.)
To: rudy45
Switch off the circuit breaker.
There are two dangers. The obvious one is someone inadvertently turning on the switch.
The less obvious one is that the neutral is not switched. Often there are are other lights on the same branch (breaker) which share the same neutral. When you interrupt the neutral or return to wire the fan, it can be connected to the hot through a device further up the line.
BTW, get a good basic guide and follow it. Time/Life books are reliable and very informative.
3
posted on
08/18/2006 3:44:23 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: rudy45
There's still a potential danger of shock with the wall switch turned off.
There shouldn't be any if the switch is wired properly, but you don't ever want to take that chance. There's a "hot" wire and a "neutral" wire. The hot wire will bite you, and the neutral one won't (or shouldn't). If it's wired properly, the hot wire will be going through the switch, and turning it off will stop the current at the switch. If it's not wired properly, and the neutral is switched it will still turn the fan off and on, but the wires in the ceiling box will still be hot even when the switch is off. All the switch is interrupting is the current path back to ground once it's left the fan. -IMHO
4
posted on
08/18/2006 3:44:42 AM PDT
by
tacticalogic
("Oh bother!" said Pooh, as he chambered his last round.)
To: tacticalogic
The neutral can be connected to the hot through a device further up the line. The neutral is not switched. When all else fails follow instructions.
5
posted on
08/18/2006 3:53:33 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: rudy45
Careful there...I'd hate to see a thread with an actual "zot".
To: Lonesome in Massachussets
That too. Either way the answer is still going to be the same - just turning off the switch is not safe.
7
posted on
08/18/2006 3:57:49 AM PDT
by
tacticalogic
("Oh bother!" said Pooh, as he chambered his last round.)
To: tacticalogic
I know a guy with a Ph.D. in EE who likes to do his own wiring who didn't pull fuses, until I pointed that out to him. IMHO, you're better off with a Time/Life book than a Ph.D. in Electrical Engineering.
8
posted on
08/18/2006 4:01:09 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: Lonesome in Massachussets
I will admit to having done it on occasion, but everything got checked with a meter and then "short tested" before I touched anything.
9
posted on
08/18/2006 4:04:31 AM PDT
by
tacticalogic
("Oh bother!" said Pooh, as he chambered his last round.)
To: Lonesome in Massachussets
10
posted on
08/18/2006 4:11:09 AM PDT
by
labette
(Let none hear you idly saying, "There is nothing I can do"...)
To: rudy45
Whatever you do, DO NOT CUT THE BLUE WIRE!!.
11
posted on
08/18/2006 4:11:41 AM PDT
by
Rome2000
(Peace is not an option)
To: rudy45
Because the typical wall switch only interrupts the connection on one of the two wires. If it was properly wired, that would be the "hot" wire, and you would be OK. However, if it was wired backwards, then all the wall switch interrupts is the neutral wire and one of those wires you will he working with will be live. Use an aluminum ladder, make a connetion to ground, seeeeeee ya. Why take the chance?
And that's only one way that current could still be present when the wall switch is off.
12
posted on
08/18/2006 4:23:15 AM PDT
by
NonValueAdded
(Tom Gallagher - the anti-Crist [FL Governor, 2006 primary])
To: rudy45
Sorry, why not take the extra precaution of pulling the circuit breaker to make sure you don't end up as a crispy critter?
13
posted on
08/18/2006 4:54:22 AM PDT
by
thoughtomator
(Islam delenda est)
To: tacticalogic
The meter won't indicate any potential until you interrupt the ground, at which time you may be dead.
14
posted on
08/18/2006 5:22:14 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: labette
15
posted on
08/18/2006 5:23:39 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: Lonesome in Massachussets
Wire nuts are removed, and all wires separated and tested for potential individually. I don't see where the meter can miss that.
16
posted on
08/18/2006 5:42:03 AM PDT
by
tacticalogic
("Oh bother!" said Pooh, as he chambered his last round.)
To: rudy45
All of the above answers are correct. You CAN get zapped on a circuit even with breakers and switches turned off. I've been working in electronics and electrical stuff since 1964, and I *usually* change out light switches and wall sockets at home with the juice turned on - BUT I'm always fully aware of which wires are which, and I don't allow myself to get between two poles of a circuit or between the circuit and ground. I act like a bird sitting on a high voltage line, which is pretty safe as long as the bird doesn't touch anything else at the time.
When I've worked in the capacity of an industrial electrician, everything is done by the book - padlocks and lockout tags on the circuit breaker or switch, probe the circuit with a voltage detector AND a voltmeter, before touching anything that might be live, don't work alone, etc, etc.
17
posted on
08/18/2006 5:48:39 AM PDT
by
Dumpster Baby
("Hope somebody finds me before the rats do .....")
To: tacticalogic
You have to handle the wires to separate them. As soon as the neutral connected to a live fixure is separated from the neutral connected to ground, it is hot.
I know that if "you know what you're doing" you can do this safely, but the folks who really know what they're doing follow the rules.
18
posted on
08/18/2006 5:52:45 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
To: Lonesome in Massachussets
I've never done this except in the case of a single-ended switch leg, with nothing downstream. I understand it's not "good practice". Not sure if I've made a bigger mistake by doing it or by having admitted to it.
19
posted on
08/18/2006 5:56:42 AM PDT
by
tacticalogic
("Oh bother!" said Pooh, as he chambered his last round.)
To: tacticalogic
Psst, I dun it, too. I won't do it again and would *never* recommend it. The older I get, the more I learn that the fewer balls in the air - the fewer corners you cut - the easier it is to finish successfully and unscathed.
20
posted on
08/18/2006 5:59:53 AM PDT
by
Lonesome in Massachussets
(NYT Headline: 'Protocols of the Learned Elders of CBS: Fake But Accurate, Experts Say.')
Navigation: use the links below to view more comments.
first 1-20, 21-29 next last
Disclaimer:
Opinions posted on Free Republic are those of the individual
posters and do not necessarily represent the opinion of Free Republic or its
management. All materials posted herein are protected by copyright law and the
exemption for fair use of copyrighted works.
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson