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MR16 differences

Discussion in 'Landscape Lighting' started by irrig8r, Oct 19, 2010.

  1. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    I finally found a local source for GE MR16s. This electrical distributor has recently changed from Sylvania to all GE.

    Local landscape/ irrigation distributors all carry only Halco or Ushio. :hammerhead:

    Looking at GE's online catalog, I'm struck by all the different MR16s available. They say that their Edison line is for landscape lighting, but I've only used the Constant Color, which is rated at 5000 hrs vs. the Edison's 2000.

    What's the diff. between a GX5.3 and GU5.3 base?

    Also trying to remember the ANSI codes match with beam spreads...but do they also match with wattage?

    Correct me if I'm wrong:

    ESX = 12 deg? But so does EXT?
    BBF = 24 deg?
    BAB = 36 deg? And so do FMW and FMT?
    FMW = 36 deg?
    FNV = 60 deg?

    I found a PDF file.. page 4 here has the whole GE Constant Color line to compare... but either online or printed it's hard to read.
  2. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    1. Stick with the GE Constant Colour line as they are a true Dichroic reflector. The edison line is their 'value' option and uses an aluminum foil type reflector coating that breaks down and results in colour shift (like so many other cheaper lines of MR16 lamps)

    2: I have never been able to find any difference between a Gx5.3 and a Gu5.3 pin designation. The 5.3 refers to the spacing of the pins in millimeters.

    3: Yes the ANSI codes refer to both the beam spreads and the wattage of the lamp. Here is some more info:

    MR16 lamps can be identified by a three-letter code created by the American National Standards Institute (ANSI). The three-letter code represents a specific type of lamp identified by its wattage, bulb shape, and beam angle. For example, "EXN" stands for 50 watts, MR16 lamp, 40 degrees or 50MR16/40°. Lighting professionals can specify MR16 lamps by their ANSI code or by their wattage, bulb shape, and beam angle interchangeably. Table 1-1 shows a partial list of ANSI three-letter designations and their abbreviated descriptive equivalent.

    ANSI designations for some MR16 lamps

    ANSI Designation Lamp Abbreviation*(wattage MR16 / Beam Angle)
    BAB 20MR16/40°
    ESX 20MR16/10°
    EXN 50MR16/40°
    EXT 50MR16/15°
    EXZ 50MR16/25°
    FPA 65MR16/15°
    FPB 65MR16/40°
    FPC 65MR16/25°
    EYC 75MR16/40°
    EYF 75MR16/15°
    EYJ 75MR16/25°
    * Data taken from ANSI C78.379-1994 Annex B
    Beam angle nomenclature:

    Beam angles are specified in two ways: by the number of degrees (for example, 40 degrees), or by nomenclature that describes the lighting effect produced by the reflector lamp. The National Electrical Manufacturers Association (NEMA) categorizes MR16 lamps as spot lamps or flood lamps. Some lamp manufacturers have created subcategories to better capture the ranges of beam angles. These subcategories are:

    * VNSP: Very narrow spot
    * NSP: Narrow spot
    * SP: Spot
    * NFL: Narrow flood
    * FL: Flood
    * WFL: Wide flood
    * VWFL: Very wide flood
  3. Classic Lighting

    Classic Lighting LawnSite Senior Member
    Messages: 512

    Thanks for the info. I've often wondered what BAB and BAF stood for.
  4. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    Thanks James. That's very helpful.
  5. steveparrott

    steveparrott LawnSite Bronze Member
    Messages: 1,276

    I'm not sure (they don't say in their literature), but I think the GE lamp uses an aluminum coating - not a dichroic. The lamps I've seen where the coating has discolored and/or flaked-off have all been dichroic.

    The CAST Service Saver MR-16's use aluminum reflectors.

    Here's a comparison of field samples:

  6. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

    Interesting Steve,

    I can see light through the cheaper MR16s when I hold them up... and the finish on some of those seems to fade and/ or flakes off eventually.

    So are they dichroic?
  7. steveparrott

    steveparrott LawnSite Bronze Member
    Messages: 1,276

    Most likely, yes.

    As many of you know, dichroic coated MR-16's were developed for retail showcases. The thinking was to use a dichroic filter to allow longer wavelength infrared radiation (heat) to pass out the back of the lamp instead of reflected forward into the showcase (causing damage to displayed products). This is exactly the wrong approach for landscape lighting since you want the heat to escape the front of the fixture - not pass into the socket area.

    This trapped heat not ony damages sockets and wiring, it burns the dichroic coating itself. That's why shiny aluminum coatings hold up better, they reflect all the heat forward.
  8. irrig8r

    irrig8r LawnSite Platinum Member
    Messages: 4,553

  9. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    As I understand it and was told by GE tech's years ago:

    The GE Constant Colour (Dichroic) MR16 lamp is unique in that the reflective surface of the mirrors is not applied to the surface of the lamp at all. It is cast inside the glass of the lamp. This makes it different than all of the other 'aluminized' reflectors on the market that have a coating applied to the mirror glass.

    Bottom line is that a lamp with aluminum coating breaks down over time from the constant bombardment of UV from the lamp capsule. This causes colour shift and lumen depreciation over time. Only the GE Constant Colour and the Sylvania Titan series use the technique of casting the reflector into the glass. Hence the higher price point of these lamps.

    Steve is right in that aluminized lamps direct all of their heat forward. In a landscape system this is acceptable but in interior applications it can be a real issue. The cast reflector lamps direct over 80% of their heat backwards, in to the fixture and off of the object, a noticeable bonus.

    I have never had a heat to fixture/socket issue using the cast reflector type lamps as we only use products that carry Canadian certification standards. ( cUL, cETL, CSA) One of the requirements of the "C" standards is a heat test. If the installed lamp creates too much heat and does not meet the CSA standard it must be rated for use with a lower wattage lamp. As far as I know UL does not have the same heat rating test. Thus, when you find a fixture that is cUL cETL or CSA rated it will also state the maximum wattage of lamp permitted (20w, 35W, 50W, 75W) If the fixture is just UL or ETL listed it generally does not show a maximum wattage rating.

    Probably too much information... LOL. Back to work.
  10. Tomwilllight

    Tomwilllight LawnSite Senior Member
    Messages: 284

    I've used GE Constant Color lamps almost exclusively for 10+ years and have never had any heat problem with them. I say "almost exclusively" because I have made mistakes buying "bargains" a couple of times.

    Lamps are the living heart of what we do. I believe that trying to save a dollar or two per lamp is a false economy.


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