free advice for the beginning do-it-yourself repairman

[BrntToast]

ALWAYS turn off the breaker or pull the house fuse to change a broken bulb or a light fixture

just because the light switch is off does not mean the wires are not live

a light switch only breaks contact on one of the 2 wires to a light fixture, if the switch breaks contact on the white return wire then you still have a live 120 volt wire right up to the fixture even when the switch is off and the light is not on

learnt this as a teenager changing a fixture for mom while standing on a metal ladder, years later i know know the theroy as to how i got my first flying lesson

[RegUS_PatOff]

Also, that ceiling light fixture (or any other box) can have a completely different (breaker) circuit traveling through it.

All of the wires might not be powered by the same circuit breaker.

[jayman73]

I always use my voltage light and check for hot wires. never know what someone has done seen one house that washer was  getting 240  a little hard  on the motor

[RegUS_PatOff]

... and after using my light stick,
I use my screwdriver to make sure there's no voltage.
(I lost a few screwdrivers)

[jayman73]

... and after using my light stick,
I use my screwdriver to make sure there's no voltage.
(I lost a few screwdrivers)

better the screwdriver than yourself

[Icehouse]

  Don't know about up North, but it is against the NEC to switch a neutral.

[Mr. Fix-It]

It is up here too but some DIYers don't know code.

[AJ]

I always use my voltage light and check for hot wires. never know what someone has done seen one house that washer was  getting 240  a little hard  on the motor

Had a refrigerator in a new house that got connected to 240 volts AC. It was a new house and a new refrigerator.

The outlet behind the refrigerator was the standard 120V outlet. The refrigerator was dead so the first thing I did was check to see if I had power to the outlet.

I had lots of power, 240Vac! I had to check it a couple times as I could not believe what I was seeing.

Not only did that outlet have 240Vac, but so did all the other kitchen outlets and all the living room outlets too.

Just about every electrical part in the refrigerator had to be replaced to repair it.

[frankster]

Don't know about up North, but it is against the NEC to switch a neutral.

What is a neutral?

[Icehouse]

What is the neutral wire?

   The utility transformer feeding your service is 240 volts single phase. In order for you to have 120 volts they need to split the voltage with a center tap at the transformer called the neutral. This is the third wire brought to the neutral buss in your main panel. This wire is also referred to as the grounded conductor. The grounding conductor is the wire attached to the water main or electrode and than to your panel and is used to ground your electrical devices. The neutral or white wire in your circuit is the return for the live feed from your circuit and is bonded at the main panel to the grounding conductor so that any stray currents caused by equipment faults will go back to the utility transformer.
Grounding
 The grounding of electrical devices is possibly the best safety precaution you can take. Grounding helps to prevent accidents to persons and damage by fire to property.
 An equipment or conductor-enclosure ground refers to connecting the non-current-carrying metal parts of the wiring system or equipment to ground. This is done so that the metal parts with which a person might come to contact is at or near ground potential. With this condition there is less danger that a person touching the equipment or conductor enclosure will receive a shock. Also metal conduit, raceways, and boxes may be in contact with metal parts of the building at several points. If an accidental contact occurs between an ungrounded conductor and its metal enclosure, a current may flow to ground through a stray path made up of sections of metal partitions, piping, or other similiar conductors.
 If the equipment is grounded, the resistance of the path through the grounding conductor will usually be much less than the resistance through the stray path, and not much current will flow through the stray path. Sufficient current will usually flow through the grounded path to blow the circuit fuse or trip the circuit breaker and thus open the circuit. On the other hand, if the equipment is not grounded, sufficient current will flow through the stray path to be a shock hazard.

[frankster]

Oh, guess that clears that up.

Thank you. 

[Repair-man]

Anybody with that many titles after his name is going to be long-winded 

[Icehouse]

 

[Repair-man]

I think I'll change mine to:

Virtual Repairman, B.S., M.S., PhA

(Doctor of Appliantology)

[Icehouse]