Power Tech
Senior Member
- Location
- Lebec, California
A customer told me not to put a Metal Halide light on a photocell. "The light will last longer". Anybody ever heard anything about this. Are they rated on starts? Vs - Hours?
MH Lighting Life?
- Thread starter Power Tech
- Start date
- Status
ericsherman37
Senior Member
- Location
- Oregon Coast
It doesn't matter what you switch them from... photocell, time clock, light switch... it matters how often it's turned on and off. Too much switching will probably reduce lamp life, but like 480 said, turning it off during daylight hours is probably better than running it 24/7.
MYTH busted, Why would the manafacturer build photo-eyes right into the fixtures ?
Lamps are rated in hours.
kbsparky
Senior Member
- Location
- Delmarva, USA
Sure the bulb will last longer if left operating continuously. BUT, you have to consider the "down time" as well when calculating total useful life.
An example would be a bulb rated for 20,000 hours would last 833.33 days.
That's over 2? years.
But, if you switched it off during the daytime (like when using a photocell), you might sacrifice 5% of its rated life -- down to 19,000 hours. Figuring in the down time, you end up with 1583.33 days --> 4-1/3 years' worth of life.
That's not counting the money you save on your electric bill operating a light during the daytime. That's where the real savings come in here: Over $400 a year!
Can you say penny wise and dollar foolish?
An example would be a bulb rated for 20,000 hours would last 833.33 days.
That's over 2? years.
But, if you switched it off during the daytime (like when using a photocell), you might sacrifice 5% of its rated life -- down to 19,000 hours. Figuring in the down time, you end up with 1583.33 days --> 4-1/3 years' worth of life.
That's not counting the money you save on your electric bill operating a light during the daytime. That's where the real savings come in here: Over $400 a year!
Can you say penny wise and dollar foolish?
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
"Penny wise and dollar foolish."
Yes!
he said 'say' it, not type it...:grin:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Well, I did say it aloud first. Note that I typed it within quotes, indicating such. :smile:
But you didn't copyright it.
It should have been:
"Penny wise and dollar foolish." ? 2009 Larry Fine.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
"Penny wise and dollar foolish." ? 2009 Larry Fine.
Done!
Done!
"Penny wise and dollar foolish." ? 2009 Larry Fine.
Done!
Too late. It's already been stolen. It's all over the internet. You missed your chance at fame and fortune.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
- Status