Jeremy Harris Posted May 31, 2016 Share Posted May 31, 2016 If the lights fall inside the SELV rules, then my understanding is that they don't need to be IP rated above IP55, and only need that if subject to water jets, if not, then IP44 is OK. The SELV rule is 12V AC or 30V DC, so LEDS running on 24V DC are inside the SELV rule. This is often overlooked or ignored, with there being lots of erroneous statements that "SELV is 12V", but that only applies to AC supplies, such as old-style halogen light transformers. Link to comment Share on other sites More sharing options...
Trw144 Posted May 31, 2016 Share Posted May 31, 2016 Will double check on selv rules but I think the leds I m using elsewhere are ip20 rated. Link to comment Share on other sites More sharing options...
Stones Posted May 31, 2016 Author Share Posted May 31, 2016 7 hours ago, JSHarris said: I fitted all our LEDs in the bathroom above the height limit, to avoid the need for IP-rated fittings. Then again, they are all 12V, so come under the SELV rules anyway. So provided I'm above the height limit, I could use these slim profile LED's that I originally linked to (be they the recessed or flush mounted type) without issue? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 31, 2016 Share Posted May 31, 2016 Yes, that's what I've done in our bathrooms. We have higher than normal ceilings, because of the room-in-roof design, so I just made sure all the lights were above the zone height limit, so no need for an IP rating. Link to comment Share on other sites More sharing options...
Trw144 Posted May 31, 2016 Share Posted May 31, 2016 So 24v ip20 LEDs would be fine above the heigh limit? Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 31, 2016 Share Posted May 31, 2016 If they are 24DC, yes. We have 12V DC LEDs in both our bathrooms, not IP rated, and they've been ticked off as being OK. Ours are set at 2.5m above the floor, IIRC, so well above the limit, and one of them is above the shower. Link to comment Share on other sites More sharing options...
Trw144 Posted May 31, 2016 Share Posted May 31, 2016 Great, thanks Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 2, 2016 Share Posted June 2, 2016 These combined extractor / lights are what I use in every job. Maybe you could connect the mvhr to them and have one less item in the ceiling ? They come with an led lamp and driver for change of £25 each. Chrome or white bezel ( comes with both ). 1 Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted June 2, 2016 Share Posted June 2, 2016 Have you got a link for those Nick ? Link to comment Share on other sites More sharing options...
Stones Posted June 2, 2016 Author Share Posted June 2, 2016 +1, look like a very neat solution. Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 2, 2016 Share Posted June 2, 2016 Cheaper than shoplifting. http://m.ebay.co.uk/itm/281298929759 Link to comment Share on other sites More sharing options...
Stones Posted June 2, 2016 Author Share Posted June 2, 2016 Nick, I'm assuming you normally install these using flexible ducting. Have you installed any with rigid ducting? Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 2, 2016 Share Posted June 2, 2016 These require a delicate touch to fit properly. A VERY snug fit in the plasterboard and then 4 x small screws trough the ring into the plasterboard, plus the two 'wing' clips that are supplied need an equally fussy eye. They're standard size for ducting and I have no doubt they'll accept some rigid pipe or other. I would say that you'll struggle not to hit these out of the ceiling whilst fitting rigid though. I can't really see any reason to try and connect rigid directly to them tbh, and it would make life 100 times easier if you just used a short piece of flexi to make this connection. You won't have issues with vacuum collapse as the flow rates are just too low with MVHR. Is that your concern. ? Link to comment Share on other sites More sharing options...
Stones Posted June 2, 2016 Author Share Posted June 2, 2016 No particular concern, just trying to be clear in my own mind about how best to fit them. Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 2, 2016 Share Posted June 2, 2016 Flexi for the local connection, and then convert to rigid at the next convenient point. There would be nothing wrong with making the first fitting off these a bend, if you needed an immediate turn due to height constraints, and then a section of flexi immediately off that, but it would imho be a right pita to try and couple these to rigid with no 'break' Link to comment Share on other sites More sharing options...
daiking Posted June 3, 2016 Share Posted June 3, 2016 On 30/05/2016 at 21:45, daiking said: From Edwardes https://www.edwardes.co.uk/en/search/p/3/q/enlite I've got a mix of Enlite EN-PL012 and EN-PL09 Seems to have been superseded by a B mod. Slight confession to make on these. I had previously stated that they didn't produce any interference - after testing the 12W units. I bought some 9W units to for my kitchen and have now discovered they interfere with FM radio within 2m or so. Not sure if its the quantity (5) or what. Will need to investigate further. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 3, 2016 Share Posted June 3, 2016 12 minutes ago, daiking said: Slight confession to make on these. I had previously stated that they didn't produce any interference - after testing the 12W units. I bought some 9W units to for my kitchen and have now discovered they interfere with FM radio within 2m or so. Not sure if its the quantity (5) or what. Will need to investigate further. That tallies with my experience. I first bought a 16W rectangular light for the hall and that was great, very nice light output and no radio interference at all. I then bought some 3W and 6W round units from the same supplier and the radio interference from them was dreadful. Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted June 6, 2016 Share Posted June 6, 2016 I've just bought a couple of 6W models from Ebay to check the colour temperatures and see what we liked. As predicted the light itself is great but the power supply has serious interference problems. It must be possible to buy reasonable quality constant current supplies from somewhere. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 6, 2016 Share Posted June 6, 2016 I cheated with the 3 W and 6 W lights and fed them with constant voltage DC, from decent power supplies, and just added a low value series resistor to get the right current. In theory this is not an efficient way to drive LEDs, but in practice the additional loss is small. Both the 6 W and the 3 W panel LEDs need 300 mA, with the voltage across the light for the 3 W units being about 10 V and the voltage across the 6 W units being about 20 V. Common frame power supplies (the ones that don't generate interference) have a +/- 10% voltage trim range, so a 12 V supply can trim from about 10.8 V to about 13.2 V and 24 V supplies can trim from around 21.6 V to around 26.4 V. I bought some 1 W rated 6.8 ohm resistors and soldered them to some wire tails and a power socket, to match the low voltage plug on the LED units. The resistor drops just over 2 V at 300 mA, so for the 3 W LEDs a 12 V DC power supply is fine (and one supply can feed quite a lot of LEDs, with a resistor by each one). For the 6 W LEDs, then a 24 V DC power supply is OK, as the voltage can be trimmed down to around 22 V to get the LEDs to run at 300 mA. This does decrease the efficiency a bit, as each resistor loses 0.612 W, so for the 12 LEDs in our kitchen I'm incurring an additional total loss of 7.344 W. We have four 6 W LEDs and eight 3 W LEDs, so the total LED power is 48 W, and the additional loss is just 15%. I can live with that, in the overall scheme of things, especially as using a single DC power supply to run several LEDs was much cheaper than having a constant current power supply per LED. Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted June 6, 2016 Share Posted June 6, 2016 I may well go down the same route, as you say the additional energy usage is minimal and sharing PSUs is going to be cheaper than individual units. I am just a bit surprised there isn't a wider range of commercial drop in replacements. I have just ordered one of these http://www.ebay.co.uk/itm/141618781550 to see if they live up to their sales blurb. I'll report back The data sheet looks vaguely promising https://cdn.shopify.com/s/files/1/0920/1206/files/12W_Constant_Current_300mA_LED_Driver_20-43v_Spec.pdf?17077483568063709960 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 6, 2016 Share Posted June 6, 2016 Reading the spec it seems that there can be 1 V of noise from DC to 20 MHz on the output! That does not bode well for low interference even in the FM band, where it'd be 3rd/4th harmonic territory. Also, the 84% efficiency figure isn't wonderful, either. I think the Meanwell supplies I'm using are around 92 to 95% efficient, so in practice there isn't going to be much of an efficiency advantage in using those constant current drivers over using a DC supply and some low value resistors. Link to comment Share on other sites More sharing options...
PeterW Posted June 6, 2016 Share Posted June 6, 2016 Is it worth adding anything such as a choke to the output cables on these units or are they just so poor in design that the RF is not easy to contain..? Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted June 6, 2016 Share Posted June 6, 2016 5 minutes ago, JSHarris said: Reading the spec it seems that there can be 1 V of noise from DC to 20 MHz on the output! That's ripple and noise - I'm hoping for 999mV ripple Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted June 6, 2016 Share Posted June 6, 2016 6 minutes ago, PeterW said: Is it worth adding anything such as a choke to the output cables on these units or are they just so poor in design that the RF is not easy to contain..? I think these thing really need to be in tin cans - cheap circuitry and plastic boxes isn't a good combination Link to comment Share on other sites More sharing options...
Jeremy Harris Posted June 6, 2016 Share Posted June 6, 2016 But the ripple will be at the switching frequency, probably around 200 kHz of so. I looked at the waveform from the constant current drivers I have and it's a series of spikes at around 200 kHz or so, there's no obvious DC on it at all. Looking at the circuit, it seems that there was no output smoothing, just raw high frequency pulses. Link to comment Share on other sites More sharing options...
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