Inrush currents and solutions......

[Dobes_88]

Good evening!

Wanting to pick the brains of people more experienced in this field, approaching 2nd fix stage of an ongoing rewire where the client wants a shed load of lights throughout.

What particularly worries me is the hallway and kitchen grid switches where there’s around 10-12 lights operated by numerous switches in each area… And he may want a couple more lights added to it!

The plan is to fit fixed Enlite E8 downlights throughout but worried about the dreaded inrush currents, have emailed Enlite to see what sort of figures I should be expecting per unit but no reply as of yet…

Would a better plan to fit LED GU10’s to limit the inrush?

It’s all wired in 1.5mm, clipped direct with switch drops in oval conduit so will be able to get away with a C10 (if Zs in limits), but with the shear volume of lights (around 25-30 x per lighting circuit) I’ve read about these inrush current limiters that could be the solution - but I haven't or know of anyone that has installed them.

Any guidance would be greatly appreciated!

 

[Pete999]

What do your circuit calculations tell you?

 

[Spoon]

I'm not domestic mate but I'm interested in the outcome to this.
A mate at work who had more wattage in his kitchen than I had in my entire house, GU10's, and never had a problem with inrush.
Would there be significant inrush if they are "operated by numerous switches"?

 

[westward10]

I would stick with the Enlites not GU10 and over order for some spares for future failure. That is a lot of lighting points for one circuit LED or not.

 

[Octopus]

Fwiw JCC have recommendations on the limits of numbers of their LEDs per circuit etc

Hopefully Enlite have similar guidance

 

[Dobes_88]

Yeah waiting to hear back from Enlite and have asked those exact questions.

Taken this job over from a mate (cheers!) and the client is fully aware there could be some alteration work to be done, wondering if people have installed one of these limiters or alike -

Inrush Limiter for LED lighting - https://uk.eaton.com/content/gb/en/products/product-catalog/lighting-controls-inrush-limiter-eaton.html

 

[PEG]

Yep,interesting,but does this device go before or after the switching?

A quick scan describes after,the circuit breaker.

 

[Leesparkykent]

I can't see it being a problem. It's not like there going to walk in and palm the switch bank so all the switches close at the same time.

 

[westward10]

I agree the in rush can be limited by division of lighting points across the switches.

 

[Madocks]

Have you considered a type c mcb?

 

[Pete999]

Have you considered a type c mcb?

Think the OP already has a C10 cb

 

[Dobes_88]

Haven't fitted anything yet, Consumer unit to be installed early part of next week and hopefully have the lights up and running towards the end of the week.

Initial thoughts is certainly a C6 or C10, will have to see what the Zs is first.

Just looking into possible solutions should the C type MCB not work, rather than flicking everything on and hoping for the best!

 

[Pete999]

Bang testing at it's best then?

 

[The Ghost]

You can buy inrush current limiters. However I think it is overhyped the problem with inrush currents. I have fitted LED panels in numbers that suggest very large inrush currents and the 10a mcb (type B) has been fine. I watched a great vid on this and they simulated the process of inrush on a specialised test rig. What it showed is the distance between the lights causes the inrush to be staggered as we are talking a peak inrush current for 500 ms only. Hence the problem is ameliorated. It is very much to do with the controller so you can look at the Inrush current for most controllers on the manufacturers site. If you do fit a limiter it should be before the switch and the switch should be rated as high as you can as it is the sacrificial part of currents. There have been cases of switches and contactor/relays welding together in these situations. So it is something to be aware of. But the LED panels I put in have been going for five years without any problems.

 

[Toneyz]

Fwiw JCC have recommendations on the limits of numbers of their LEDs per circuit etc

Hopefully Enlite have similar guidance

I would echo what Murdoch above posted (BTW apologies for spelling your name wrong in a previous post-Murdoch) It does also seem to be a lot of lights on one circuit.

 

[davesparks]

What do your circuit calculations tell you?

How can he calculate this when the manufacturers haven’t supplied the required information?

 

[Octopus]

The guides and regs don't help .... As far as I know they still suggest we should allow 100w per light fitting .....

We all know that this is very out if date...

How many light fittings in total are there on this circuit?

 

[sam400]

I keep telling people installing LEDs is a dark art but no one believes me! Lol
I have fitted quite a few enlites on b curve breakers and not had a problem.
But got caught out once by 3 JCC under unit lights that I had to put on a C10 to stop it tripping.
I recently contacted JCC about some LED panels I was fitting and they said they pull 36A per fitting on start up!
(Only for 20 uS tho)

 

[1Justin]

I'd be surprised if you can get a figure from Enlite, but if you do, then let us know! With domestic lights I don't think you will have a problem though.
I have had issues only once, but that was fitting 11 off 30W floods with Meanwell drivers. I eventually needed to fit a C16 breaker and only just got away with the cable installation I'd already done, phew..

 

[ImpededLoop]

12x E8's shouldn't cause you any issues on a B6 (even on one switch). I've seen it done a few times recently.

If Enlite do supply any data, please share it with us as it would be interesting to look at.