Quick electrical question

[119]

Friend of mine has a shop with ceiling panels and square 4 way flourescent fittings and we swapped them out for JC led panels.

There are about 15 in place now and every time he switches them on the circuit trips in the fuse box.

If he resets it they seems to then stay on.

This keeps happening and I read that led can have a high start power which can cause this to happen?

Is there an easy way to solve this?

Someone mentioned getting someone in to change the fuse breaker to a C model or a 10amp b model

[caziques]

D curve breaker is possibly what is required.

Used where there can be a high inrush current.

[megaphone]

Is the circuit breaker tripping (MCB) or the RCD? What rating is the MCB?

[119]

It is the circuit breaker and it’s a b6(?)

He dug out the invoice and its these...


https://jcc.co.uk/products/jc080218

Edited by 119 on Wednesday 9th April 08:11

[megaphone]

The link says the panels are 30w each x15 = 450w. So around 2 amps. Well within the rating of the 6 amp breaker.

Has he checked the cabling and connections? Is there anything else connected on the circuit?

[Richard-D]

megaphone said:

The link says the panels are 30w each x15 = 450w. So around 2 amps. Well within the rating of the 6 amp breaker.

You're right that the rating is fine for the average current draw. As pointed out above though, the inrush current will be far higher.

[Mr Pointy]

If the panels are dimmable then change the switch to a dimmer switch which will soft start on switch on.

[119]

Thanks all.

No there is no dimmer on any of them as it’s for a shop and there is no need to dim them.

The set up is, a main switch by the door that turns off all the lights and a selection of sockets and this controls a big contact switch?

There are around 25 lights in total, and it’s actually 18 on one mcb circuit and 8 on another mcb circuit.

The one with 8 is fine but the other one is the one that trips.

[megaphone]

So the circuit is on a contactor? That could be causing an issue when it activates.

[Simpo Two]

119 said:

There are around 25 lights in total, and it’s actually 18 on one mcb circuit and 8 on another mcb circuit.

The one with 8 is fine but the other one is the one that trips.

Can you change the wiring so it's 13 + 13 rather than 18 + 8?

[119]

megaphone said:

So the circuit is on a contactor? That could be causing an issue when it activates.

Contactor that’s it.

So, just found that the whole separate fuse box with these lights and other sockets is controlled by the contactor.

ie the mains cables to feed the fuse box are fed from this contactor.

If that makes sense

As for rewiring, possibly but the mess of cables above the ceiling is quite staggering and it may be tricky to see which cables are which!

He has ordered 2 x C6 mcbs to try but he can do that.

[119]

Forgot to mention that we disconnected two and it seems to behave.

[119]

Just to close this off, he changed the fuse breakers to the C type and all is good.

[119]

Soooooo dragging this back.

I haven’t seen him for a while and caught up with him today.

Turns out the c6 breakers aren’t any good either as they still trip but not as often.

I just re visited the replies so I suggested he should look at fitting d type?

Or should he try maybe a c10?

Thanks again all

[thebraketester]

Shop? Commercial? Probably best to get a qualified electrician in for insurance purposes etc etc.

[Belle427]

I have never seen D type mcbs on commercial lighting circuits, C maybe yes.
There are safety implications of changing the tripping characteristics, Im not clever enough to explain it to you but a quick google will help you.
Best seek professional advice.

[119]

Yeah sounds like this is getting way too complicated.

He will have to put his hand in his pocket and get someone proper.

Thanks guys.

[JimbobVFR]

Belle427 said:

I have never seen D type mcbs on commercial lighting circuits, C maybe yes.
There are safety implications of changing the tripping characteristics, Im not clever enough to explain it to you but a quick google will help you.
Best seek professional advice.

Me neither, I would say they're specifically for "motor" loads and nothing else.

[ruggedscotty]

Type A: Trips at 2–3 times the rated current. This type is very sensitive and used for sensitive electronic equipment, but it is not recommended for motor circuits.

Type B: Trips at 3–5 times the rated current. This is the most common type for residential use and is suitable for resistive loads like lighting and standard outlets.

Type C: Trips at 5–10 times the rated current. This type is used for commercial and industrial applications with higher inrush currents, such as fluorescent lighting and motors.

Type D: Trips at 10–20 times the rated current. This type is designed for circuits with very high starting currents, such as large motors, X-ray machines, and welding equipment.