I recently bought a used IKEA ceiling light however when getting it home noticed that it seems the live wire is connected to a thermistor? which then has another short wire where you connect to mains via a gripper connector (excuse the terminology - im no expert). Picture of wire: HR250-080 thermistor

So having googled the writing i locate the manufacturer sheet for the item: Link to part sheet However i cannot find this part to buy online. Is anyone able to help translate this into what i need to look for to buy a replacement part? I'm based in the UK so somewhere like RS Components would be good.

Appreciate any help you can offer. I dont want to bin the item for such a tiny component that would be easy to remove and add a new one.

Thanks Ben

Added wire diagram - Orange blob is the thermistor/varistor wiring

  • 1
    \$\begingroup\$ Could also be a MOV. We're going to need to see more of how that is wired. \$\endgroup\$
    – rdtsc
    Sep 10, 2021 at 16:56
  • \$\begingroup\$ ok sure. tell me what you need an i will advise. But in summary it is connected to the brown live wire on the lamp fitting. this will join to the live wire of the mains. The other blue (neutral) wire on the lamp fitting is just a wire. \$\endgroup\$
    – bendpsmith
    Sep 10, 2021 at 17:52
  • \$\begingroup\$ Added a diagram if it helps. @rdtsc Also this is the lamp in question: ikea.com/gb/en/p/… \$\endgroup\$
    – bendpsmith
    Sep 10, 2021 at 17:59
  • \$\begingroup\$ Welcome! If it were me I would take it back, they may simply replace it. \$\endgroup\$
    – Gil
    Sep 10, 2021 at 18:18
  • \$\begingroup\$ @Gil i bought it used on facebook marketplace. so cant take back for replacement. i've told them i'll be bringing it back to them if i cant fix. but for the sake of one component that is easy to replace (when i know what i need) i'd rather try not waste it. \$\endgroup\$
    – bendpsmith
    Sep 10, 2021 at 18:32

1 Answer 1


I entered the numbers you so plainly showed on the device and got an immediate hit. It is an electronic fuse or Polymer PTC. Here is the link so you can check it yourself: http://www.hr-ptc.com/en/hr250/141-hr250-080.html They have a contact us on the top where you can email them. Try that, Show a picture and state you cannot find a replacement. Be sure to include your mailing address they may simply send you a sample.

  • HR250-080

    IH = Hold current : maximum current at which the device will not trip at 25℃ still air.

    IT = Trip current: minimum current at which the device will always trip at 25℃ still air.

    Vmax = Interrupt voltage device can withstand without damage at rated current.

    I max = Maximum fault current device can withstand without damage at rated voltage.

    Ttrip = Maximum time to trip(s) at assigned current.

    R min = The smallest zero power resistance under the ambient temperature of 25℃.

    R max = The biggest zero power resistance in the ambient
    temperature of 25℃.

    R1max =Maximum device resistance one hour after it is tripped at 25℃.

I believe that answers your question. They are readily available from many suppliers and you should not have any problem replacing it.

I googled "replacement HR250-080" and the first hit was AliExpress and it showed the part for $0.18. That should get you back up and running only will take a few weeks for it to arrive.

  • \$\begingroup\$ Hi @Gil Thanks for this. I managed to find the same URL. The problem i have is i cant find anything on RS Components, Mouser, etc with the same stats as this. The stats quoted on the HR-PTC website seem to be different than those on the other sites. If you could be so kind as to help me find one i'd be super appreciative. Ben \$\endgroup\$
    – bendpsmith
    Sep 11, 2021 at 14:23
  • \$\begingroup\$ Hi @bendpsmith, I have literally just done exactly the same thing as you in breaking this thermistor, good too see I'm not the only wally! Did you manage to find a direct replacement? My light doesn't seem to turn on without it(?). \$\endgroup\$
    – madz
    Oct 3, 2021 at 18:36

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