MR11 Halogen 12v to LED mains

Discussion in 'Electricians' Talk' started by The Magic Rat, Jan 16, 2020.

  1. The Magic Rat

    The Magic Rat New Member

    I have 18 x MR11 Halogen 20w 12v bulbs in a home office. Each 12v transformer supplies three bulbs on a harness. I ordered in 5w LED MR11 in 12v but 240v have arrived from eBay. I already have a new LED dimmer switch and LED drivers ready.

    My question is can I run the 240v MR11 without the 12v transformers?

    The existing load per harness is 60w at 12v. The new load would be 15w at 240v.

    The LED bulbs are a full glass COB type and look so much better than anything else I have found. I'm struggling to find such a good 12v equivalent.
     

    Attached Files:

  2. KIAB

    KIAB Super Member

    MR11 lamps are 12v only.

    If you want 240v lamps then look at GU10 lamps & changing existing downlight fittings to suit.
     
    rogerk101 likes this.
  3. The Magic Rat

    The Magic Rat New Member

    Thanks for your quick reply. I fitted GU4 as the spacing was tight and I can't re-cut for a larger diameter.

    Picture attached of the 240v GU4.

    I can get 12v GU4 and go that route if necessary. I'm hoping the existing wiring harnesses (with transformers removed) will be adequate for a change to mains 240v at a much lower amperage (75% lower). The heat will be much less as well.
     

    Attached Files:

  4. KIAB

    KIAB Super Member

    A GU4 MR11 lamp is definitely NOT 220v, it is a low voltage 12v lamp.
     
  5. The Magic Rat

    The Magic Rat New Member

    Tested with existing 12v transformer and also 12v car battery and they don't light.

    I can test with a mains feed but almost certain they are 220/240v.
     
  6. seneca

    seneca Screwfix Select

    I would have said the same as the others but I see on the box it says MR11 led and 220 volt so I assume the regulators/drivers are contained within the lamps.
     
  7. KIAB

    KIAB Super Member

    They shouldn't be allowed to be sold here or on Ebay for UK use.
     
    Last edited: Jan 16, 2020
    rogerk101 likes this.
  8. seneca

    seneca Screwfix Select

    I agree KIAB, certainly not under the guise of MR11 anyway.
     
    KIAB likes this.
  9. KIAB

    KIAB Super Member

    Trading Standards!
     
  10. The Magic Rat

    The Magic Rat New Member

    I'm guessing they work the same as LED bulbs for replacing incandescent bayonet and screw cap bulbs which are all 240v. You can touch the bulbs after an hour of being on and they're not even warm.

    Is this correct? 3 x Halogen 20w 12v bulbs on a harness draw 5 amps and 3 x LED 5w 240v bulbs draw 0.6 amps?

    I'm thinking of connecting a single harness to a 3 amp mains plug and running three bulbs for a day on a concrete floor. If anything gets warm I will abandon the idea.
     
  11. Mike58

    Mike58 Screwfix Select

    0.0625 A or possibly a little more, say 0.1 A
     
  12. rogerk101

    rogerk101 Screwfix Select

    I wouldn't install those lamps in my house. Cheap Chinese carp might save you a few quid, but they also might burn your house down, along with those in it. I just hope you don't live in a flat or a terrace, because that would put other families at risk too.
     
    KIAB likes this.

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