LED strips on lighting circuit

[Kyrt]

Firstly the short version: can XLG LED power supplies be used on a lighting circuit?

The long:

I am renovating a large room and this includes running relatively long lengths of RGB-CCT LED strip. I have a pair of Mean Well XLG-150-24 power supplies feeding 24V strips via a controller and amplifier (https://eu.mouser.com/ProductDetail/mean-well/xlg-150-24-a/) though may need them to uprate the power supplies in the end (final calculations of current draw).

I was (perhaps naively) assuming that being designed as LED power supplies I can connect them to the lighting circuit, which feeds the 3 reception rooms on the same 6A breaker. The total power and current @ AC voltage is well within what traditional incandescent lighting would consume so didn't expect it to be an issue. Since all I am doing is replacing the light fitting and don't need to modify any wiring, I figured I could do this work myself.

However the MCB is sometimes tripping when this circuit is first turned on. It's fine after flipping it back, whether output is loaded is or not. Now looking in detail at the datasheet I see there is a 50A inrush current specified. This makes me wonder if the cause is the caps charging when starting from cold; once charged it's fine. The spec says I should be able to use 4 PSUs (circuit breaker of type B) though, and even I need to upgrade to 240W supplies I should still be able to connect 2. Am I wrong in my assumption: should I simply not be using these supplies, and if so what should I be using? Should I have them wired to the socket circuit instead? Do I just need to replace the 6A breaker for a bigger one? (not sure if that last one counts as 'like for like' work I can do myself).

 

[flameport]

A 50A inrush current will easily trip a 6A type B MCB.

Whether the MCB can be changed for a different one depends on the cable size used, how it's installed, the circuit impedance and various other things.

 

[Kyrt]

A 50A inrush current will easily trip a 6A type B MCB.

Whether the MCB can be changed for a different one depends on the cable size used, how it's installed, the circuit impedance and various other things.

Thanks, sounds like I need a sparky to work this out? I can obviously check the wiring used for circuits that are visible and in particular in this room, but wouldnt know how to determine the rest of it I can't see, and wouldnt know how to interpret the answer. Is 6A the max for 1mm, and what about 1.5mm? I don't know the relationship between the inrush current and the "normal" current either.

Going the other way around, if I wanted to run 2 of the largest drivers (inrush current upto 170A + whatever else is on the circuit), what size wiring and MCB would be needed? The reason I ask is I could instead run these off the socket circuit (2.5mm2 and 32A), it's just the lighting circuit is "neater" and would have expected this to be a more normal installation.

 

[DetlefSchmitz]

The data sheet suggests they are constant voltage, constant current and constant power, and seems to require a special controller in addition. Frankly I can't get my head round it.

 

[EFLImpudence]

socket circuit (2.5mm2 and 32A)

2 x 2.5mm2 and 32A

 

[Kyrt]

2 x 2.5mm2 and 32A

Assuming someone hasnt cocked it up somewhere yes!

 

[Kyrt]

The data sheet suggests they are constant voltage, constant current and constant power, and seems to require a special controller in addition. Frankly I can't get my head round it.

Yes I tried to keep it short(er) so left out exactly how it works. Maybe the PSU can do more but in my case it's just a constant-voltage power supply and maintains that voltage across the full power range. There's a PWM controller on the output that controls the strip light (that's how all multi-colour strip lights work, in this case there's 5 channels and +24V). In my case I have 1 PSU powering a zigbee controller, and 1 PSU powering an amplifier. The output of the controller feeds 2x runs of LED strip and the input to the amplifier, and the output of the amplifier feeds another 2x runs of LED strip. This is the most efficient way to run them while minimising voltage drop and current over the length of each strip and intermediate 6-core wiring.

 

[Colin Brenton]

Can the controllers be programmed for a slower/more gentle start? This is often a problem in electronics, and chips called 'hot plug controllers' are used to control the inrush current (which would otherwise be present to charge large value caps) when the thing is first connected/switched on.

It does sound like it is the in rush current knocking the MCB off in this case, rather than a fault as such.

The guys will be able to advise more if changing to a different 'curve' type C (or even D) might be possible, to keep the over current and short circuit protection and allow the breaker to hold 'on' for an inrush spike. Think of it as a 'slow-blow' or 'time delay' fuse.

Just some thoughts fwiw.

Good luck!

Cheers,
Colin

 

[imageel]

Hi, I use similar ELG-100 24v PSU's to drive LED's in my house and although lower power than yours the spec sheet recommends a max of 3 PSU's on a 16A type B breaker or 6 on a 16A type C.
For your XLG-150 they recommend a similar 16A breaker with a max of 4 PSU's on a type B or 8 on a type C.
I've had no nuisance trips with 2 PSU's on the same breaker and they have been in service over a year.
These PSU's appear to have rather large inrush currents, I suspect because of the additional active PFC cct, however the upside is they are pretty efficient >90%
Cheers
Ed