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Recessed can lighting voltage

  1. Mar 29, 2012 #1


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    I have some recessed can lighting fixtures in a commercial application that was using compact 277v fluorescent bulbs (2x26w). I have purchased a can light fixture that will hold one spiral 277v fluorescent (27w), which allows us to get away from having to purchase two lights + ballast. However, the actual socket in this new fixture says it is rated for 600w and only 250 volts.

    I would like any input you can offer on if this application is safe or not. I am guessing that it would be fine, as the amp draw from this one light is only 0.170A, but I wanted to see if there is anything I am not taking into consideration.

    Any information or advice is appreciated.

  2. jcsd
  3. Mar 29, 2012 #2

    jim hardy

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    Arrgh !!!

    One of those things your common sense says it's fine

    but you gotta meet the letter of the specifications............

    liability and all that.

    Find the fixture's datasheet at manufacturer's website

    and check your installation against the NEC .
    There are separation requirements between 120/240 and 277/480 volt systems and from your description your fixture is 240 going into a 277 system. I dont know if there's any differences in mechanical construction or wire colors.
    You dont want to do somethiing that's going to lead the next guy astray.

    From a handyman's reference:
    old jim
  4. Apr 7, 2012 #3


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    The SOCKET is rated for 250 v and 600 W MAX.
    The lamp operates at LESS than that.
    Just because the input to the ballast is more (277v), doesn't mean the output of the ballast is that high. Most if not all fluor. lamps operate at much less voltage. You can verify this by looking at the ballast specs from the manufacturer.
  5. Apr 8, 2012 #4


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    Could MacLaddy confirm that the spiral compact tube has an integral internal ballast?
  6. Apr 8, 2012 #5


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    Thanks for the replies everyone. I thought my question had disappeared into the bowels of PF, never to be seen again.

    Yeah, the icky word "Liability." That's exactly what worries me. I did install one fixture, and it seems to work just fine. However, my upper management decided they didn't like the look of the spiral fluorescent, so we will be staying with the original compact fluorescent.

    Yeah, as I said in the OP the lamp itself operates at just over 1/10 amp, and only 27 watts. There was no real concern here, but I was worried about a liability issue just in case of some unforeseen failure.

    Yup, integral and internal. :biggrin:
  7. Apr 9, 2012 #6


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    Welcome to PF, wirenut. :smile:

    I surmise that you are picturing an external ballast reducing the potential that appears across the lamp terminals. In light of the OP's indication he is using lamps with an internal ballast, then there can be no external ballast and therefore no difference between line voltage and what appears across the lamp socket. Besides, even were there an external ballast, picture the voltages when the lamp dies…

    Good try, though. :wink:
  8. Apr 10, 2012 #7


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    I did some checking on these, even though they are UL listed, I would stay away only because you are putting 277 volts on a e26 (standard incand. medium base). Unless the fixture is clearly marked as 277 volts there is a chance for injury or fire if a 120 volt lamp is installed. My next question would be- Is the new fixture rated for 277 volts? If you have a manufacturer name and model # it would help . I know the point is moot, but for info sake (so I can let guys @ work know to look out for them). I see BAD things happening. I also am not sure if they comply with the NEC. I'll have to look into that too.
  9. Apr 11, 2012 #8


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    Are you saying that (wherever you are located) the sockets for
    277V and 250V lamps are constructed so they will physically
    accept 120V lamps? :uhh:
    Underscores the meaning of the word "incandescent", doesn't it? xQEdJ.gif
  10. Apr 11, 2012 #9
    The dieletric strength of the lampholder is marked as you say for 250v, this is not to say it cant be used for your application, it is probably for a market where that is the common single phase voltage and thus printed to match the market its designed for, im from England and our own Reg's now state that manufacturers recommendations must be adhered to, having said this if you can discuss with the lampholder manufacturers and get and email of confirmation that it will be ok to use at 277v then i feel you will have provided enough covering details to protect you from liability.
    It just comes down to whether its easy enough to fit a lampholder yourself with the correct rating as im sure if they sell the lamps at 277volts then surely lampholders should be within your reach too.
    Our own voltage on paper changed 5yrs ago from 240v to 230v and over the years ive seen the exact same lampholders change their stickers to suit but our voltage has remained the same, you may find the lampholders are just sourced from another country and are ok to use but i reitirate that id get confirmation fron the manufacturers first.
  11. Apr 17, 2012 #10


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    here is a TCP part # for a 277v compact fluor. spring lamp with a MEDIUM base-Product
    Name: SpringLamp 42W 4100K 277V CFL

    Product #: 28942-277-41K

    Manufacturer: Technical Consumer Products, Inc., TCP

    here is the product specs from the TCP website
    Product Info

    The TCP 289-series Compact Fluorescent SpringLamps feature lead-free glass for better lumen maintenance over life of bulb. End of life protection guards against violent lamp failures. New amalgam technology provides cooler operating temperatures for consistent performance in any position.

    Average Rated Life (hr): 10000

    Base: Medium <------------------------- this is my concern

    Color Rendering Index (CRI): 84

    Color Temperature (K): 4100

    Diameter (in): 2.8

    Energy Star Qualified: Yes

    Industry Standards: UL and CUL Listed, FCC Part 18, Subpart C

    Initial Lumens at 25C: 2800

    Maximum Overall Length - MOL (in): 7.0

    Starting Temperature F (C): -20

    Voltage: 277 <---------------- this too

    Watts: 42
    Here's a link to the info- http://www.tcpi.com/specsheets/Asso...entID=2219&DescriptiveName=289 Series 18w-68w

    I'm not sure if you understand my concern, but if someone unknowingly installs a 120 volt unit into a fixture wired for the 277v units WITHOUT any kind of warning label etc... best case the lamp burns out instantly.... worst case catastrophic failure possibly fire, injury, death etc..

    BTW i'm in new york
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