Fact or Myth...

[stickboy1375]

Is it a fact that screwing in a PAR lamp, or any lamp for that matter with the switch on causes premature failure or certain death of the lamp? Or more of a safety concern?

 

[480sparky]

If at all possible, I install (edison-base style) bulbs.....er, sorry.... lamps while the power is on.

If this is wrong, I guess I've been doing it wrong for years.

 

[chris kennedy]

certain death of the lamp?

Isn't this inevitable no matter how the lamp is installed?

FWIW, I prefer to install lamps with power off.

 

[stickboy1375]

If at all possible, I install (edison-base style) bulbs.....er, sorry.... lamps while the power is on.

If this is wrong, I guess I've been doing it wrong for years.

I dont have a problem either way, just something my boss said to a customer and I kinda just shook my head. Should the truth be known, the lamp blew as it was being screwed in, I figured it would have blown if the switch was off, then turned on of course.

 

[stickboy1375]

Isn't this inevitable no matter how the lamp is installed?

FWIW, I prefer to install lamps with power off.

I agree, just reassuring myself thats all.

 

[chris kennedy]

Interesting question none the less. Hope this gets more play.

 

[djcrzysounds@yahoo.com]

The worst it could be is a few small arcs from the base of the lamp to the lamp holder contacts. IMHO, I don't think it matters... although 1000 watt incandescent lamps get hot quick and those suckers(cough lamps) get hot quick.

 

[MF Dagger]

I screw them in with the lights on when I can. It helps me know if the lamp is bad before I move the ladder for one thing and for another I feel that overscrewing a lamp into a socket weakens the contact inside of the socket.

 

[ce2two]

ce2two

ce2two

street lights in so. cal freeways ,these are mogul base taken out at night time, plug in another one with circuit hot, try finding the service off the side of the freeway every time u have change a light huh.....the boss would laugh ,and probably sent u out on signal calls? instead

 

[hillbilly1]

I have a habit of doing it also, but not to get too far off the original post, We had to go out to a big box store parking lot where the parking lot lighting maintaince contractor had installed a lamp with the power on, and the lamp shattered connecting him to the live electrode inside electrocuting him. The fire department would not get him down until we verified that he was no longer connected. Sad accident, I think the kid was around 22 or 23.

 

[stickboy1375]

I have a habit of doing it also, but not to get too far off the original post, We had to go out to a big box store parking lot where the parking lot lighting maintaince contractor had installed a lamp with the power on, and the lamp shattered connecting him to the live electrode inside electrocuting him. The fire department would not get him down until we verified that he was no longer connected. Sad accident, I think the kid was around 22 or 23.

damn.... that is sad, but in the same breath, preventable.

 

[ce2two]

ce2two

ce2two

at one time we had work with series street lighting 5000vac @6.6 amps ,at the light standard u had 240vac. or 480vac., talk bout dangerous ,grounding that was another story ......in it's self ....wear gloves and eye protection ?

 

[pfalcon]

Last I heard but cannot confirm the veracity thereof:

With the light on during installation you can flicker the bulb when it first makes contact - thereby shortening the bulb life since cycling shortens the bulb life.

With the light on during installation - you get blinded.

If you touch the bulb with your bare hand you leave oily hot spots that shorten the life span. The heat when it turns on may cause additional sweat to shorten the life span.

 

[cowboyjwc]

I have a habit of doing it also, but not to get too far off the original post, We had to go out to a big box store parking lot where the parking lot lighting maintaince contractor had installed a lamp with the power on, and the lamp shattered connecting him to the live electrode inside electrocuting him. The fire department would not get him down until we verified that he was no longer connected. Sad accident, I think the kid was around 22 or 23.

Acually had the same thing happen to me, luckly with a different result of course. That's to bad.

I was once told that you should put in bulbs with the power on as soon as the lamp lights just give it like another quarter turn. It's supposed to keep you from smashing down the tab on the fixture. Just what I was told.

 

[Jraef]

Last I heard but cannot confirm the veracity thereof:

With the light on during installation you can flicker the bulb when it first makes contact - thereby shortening the bulb life since cycling shortens the bulb life.

With the light on during installation - you get blinded.

If you touch the bulb with your bare hand you leave oily hot spots that shorten the life span. The heat when it turns on may cause additional sweat to shorten the life span.

One or two extra "flickers" is not going to make a noticeable difference in bulb life. But the point about being blinded is valid, especially if you are on a ladder. Oil on the hand transferring to the bulb is a factor only in quartz lamps.

The biggest deal is the "bad lamp detector" issue mentioned above. If the lamp is defective right out of the box, as evidenced by the horror story above, hot installation is a really bad way of discovering that. When I worked for a distributor, lamp mfrs had an allowance of 15% usage reimbursement to cover defective lamps. So in other words, they ACKNOWLEDGED up front that they expected 15% of them to be defective and distributors could replace them, no questions asked. Of those, not all of them are going to pop in your hands when energized, but Murphy's Law prevails and when it happens to you, it will be at the worst possible moment!

 

[petersonra]

One or two extra "flickers" is not going to make a noticeable difference in bulb life. But the point about being blinded is valid, especially if you are on a ladder. Oil on the hand transferring to the bulb is a factor only in quartz lamps.

The biggest deal is the "bad lamp detector" issue mentioned above. If the lamp is defective right out of the box, as evidenced by the horror story above, hot installation is a really bad way of discovering that. When I worked for a distributor, lamp mfrs had an allowance of 15% usage reimbursement to cover defective lamps. So in other words, they ACKNOWLEDGED up front that they expected 15% of them to be defective and distributors could replace them, no questions asked. Of those, not all of them are going to pop in your hands when energized, but Murphy's Law prevails and when it happens to you, it will be at the worst possible moment!

I didn't know about the 15% allowance, but I have heard from some bulk users of lamps that lamp manufacturers usually give you 2-5% more than you actually bought as replacements for DOA units.

 

[whillis]

Screwing in an incandescent type lamp to an energized socket can kill it because the twisting motion causes the hot, soft filament to break. Same effect can be had by shaking an incandescent when it's on. This is the reason that there were "shop rated" bulbs for those old mechanics trouble lights you used to see in garages everywhere. (still do in some I guess)

I always thought it was strange how the headlights on my 4x4 could survive the roughest trail yet bumping one of those trouble lights, even with the shop rated bulb, just a bit to hard against the car fender would break the filament. If they could make one bulb last, why not the other?

 

[LarryFine]

If they could make one bulb last, why not the other?

Because the low-voltage bulb has a short, thick filament, while the high-voltage bulb has a long, thin one. Ohm's Law. :smile:

And, of course, engineering for the specific environment. Thus, the rough-service bulbs, usually with extra filament supports.