Return to the Electrical Wiring Forum | Post a Follow-Up

 o
HPS parking lot lighting.

Posted by newgarageguy (My Page) on
Sun, Nov 20, 11 at 21:16

What happens when the wrong wattage lamp is installed in a HPS fixture? 150 watt lamp in a 250 watt fixture. Or vise versa?


Follow-Up Postings:

 o
RE: HPS parking lot lighting.

Fire and brimstone coming down from the skies! Rivers and seas boiling!
Forty years of darkness! Earthquakes, volcanoes...
The dead rising from the grave!
Human sacrifice, dogs and cats living together... mass hysteria!

A ballast that is too small for the lamp may not fire it.
A ballast that is too large may cause excessive heat and burn it out.


 o
RE: HPS parking lot lighting.

Hahahahahahaa.

Thanks.


 o
RE: HPS parking lot lighting.

Most of us have no definitive answer since we never tried what you suggest. No experience. My answer would be only a guess. And I never tried it since it probably would ruin the lamp or the ballast or both. And I did not want to know badly enough to spend the money for those components. If you try it, please advise the results you observed.


 o
RE: HPS parking lot lighting.

I haven't tried it nor do I plan to. I am just curious. I have found fixtures with the wrong lamps in them after they have burned out but I have no idea how long they have been that way. It seems to not hurt the ballast. After relamping, the fixture appears to work correctly. I have asked an electrical engineer this question. Go figure, he couldn't answer.


 o
RE: HPS parking lot lighting.

Many of the newest ballasts have thermal overload to protect themselves.
What they do not protect against is over driving of the lamp they are connected to.

Once the discharge starts (in just about any discharge bulb of any type) the impedance of the bulb becomes very low (close to zero).
The ballast then limits the current flow to a safe level based on the bulb it is designed to operate with.

Use a smaller wattage bulb and the current is going to be higher than the bulb was designed for and bulb life may be short (possibly as short as a fractions of a second).

Older all magnetic type ballasts are more likely to suffer damage than newer electronic ones.


 o
RE: HPS parking lot lighting.

Thank you Brickeyee,
Have a happy Thanksgiving.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Electrical Wiring Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here