New wall-lights in office keep blowing bulbs and trip'ng RCD

[skotl]

We got an electrician in to replace 60 wall lights in the office, which are spread across four floors and 5 RCDs (on two different CUs).


They look a little like the enclosed picture (but are not exactly the same). Behind the screen are two E27 fittings and the electrician has put 2 x 70W halogen bulbs in every light.

Untitled

• skotl
• 27 Feb 2013
• 1

The problem is that around twice a week we lose a bulb and, when that happens, it takes out its neighbour (in the same light) and trips the RCD.

There is no sticker on the light stating what the maximum wattage is but, to me, 140W for every fitting (there are four in an average sized room) seems overkill.

Before the lights were replaced we didn't have this many failures (previous lamps were single 100W units) - do you think that if I simply replaced every single bulb with a pair of 27W low-energy bulbs, that would slow down the attrition rate and would stop tripping the RCD when we do lose a bulb?

You may suggest I get the electrician in but, TBH, it was his spec in the first place and we've had the lights for around four months now.

Ta in advance

 

[ban-all-sheds]

He deserves a good kicking.

Even if they weren't failing all the time you should be using fluorescent lamps.

Is anything stopping you, such as dimmers, PIRs?

 

[Taylortwocities]

RCD?????????
Are you SURE????

RCD tripping would mean an earth fault.

Perhaps you mean MCB?


RCDs and MCBs do different jobs.

Here's how you can spot the difference:

Untitled

• Taylortwocities
• 27 Mar 2010
• 43

 

[skotl]

BAS - thanks for that, glad it's not just me then
Taylor- You'll be right - that was me trying to portray that I knew what I was talking about; should have said "trippy switchey thing" which you'd have recognised as an MCB

 

[ericmark]

60 x (2 x 70) = 8400 W / 230 = 36 A / 5 = 7.3 A per circuit and most lighting circuits use 5 A fuse or 6 A MCB so it would seem likely the circuits are overloaded. Likely not completely balanced between the 5 circuits so could be worse.

We are permitted 16 A overload devices to feed lamps but only if all the items on that circuit can take 16A. The humble ceiling rose which also acts as a junction box is only rated at 5 or 6 amp. So often in real terms limited to 6A MCB.

In the home to swap for a 10 amp MCB may work but in commercial premises one has to be very careful as cable runs tend to be longer and so earth loop impedance and volt drop have to be considered.

Corporate image is also important so lights have to look good. However in today's climate using energy guzzling lamps will not be doing the corporate image much good.

Lighting as I found to my cost is not easy. I swapped banks of florescent tubes for low bay metal halide with a 25 foot ceiling which was a huge success. So then did next shed with 15 foot ceiling and it was a failure. Ceiling just too low. So I would not even try to say what type of lamp should be fitted without walking the area.

However it would seem mistakes have been made in your case. I think it is easy for a domestic electrician to think of diversity as in the home all lights are not all switched on all day. But in an office quite common for all lights to be switched on all day.

 

[ban-all-sheds]

I'm just gobsmacked that in this day and age anybody would consider 8.4kW of lighting to be a good design without doing a lot of work to rule out possible more efficient solutions.

Even without re-lamping costs that's over £2K pa for electricity, assuming 5 days a week, 10 hours per day.

 

[Lectrician]

They remind me of some Ansell wall lights I fitted last year.

http://www.anselluk.com/products/Acqua-Inox-Stainless-Steel/c51

They came in 75watt E27, or 18watt PL.

Perhaps your could of come as different types too. Too late now, but PL variants would have been the way to go for that qty of lights, on for that length of time. The initial extra cost would of been cleared SO quickly due to lower lecky bills and reduced re-lamping costs.

 

[ban-all-sheds]

The tests are not difficult to learn, and the equipment can be found on eBay for affordable amounts.

Where the years of training and experience comes in are in areas like ... knowing what products are available.

 

[RF Lighting]

I'm just gobsmacked that in this day and age anybody would consider 8.4kW of lighting to be a good design without doing a lot of work to rule out possible more efficient solutions.

Even without re-lamping costs that's over £2K pa for electricity, assuming 5 days a week, 10 hours per day.

Even I would never consider that an acceptable installation for a commercial setting. Where did you get this guy from? I'm guessing he's never actually designed commercial lighing schemes before?

I really feel sorry for people like the OP who have been duped into having a completely unsuitable installtion carried out and are now having to pay for it, and will continue to do so for the forseeable future.

Changing to CFLs would be a good start, but it still sounds like a dreadful way to light an office.

 

[ericmark]

I do wonder how hot a wall light will get with those bulbs and if they could burn ones self if touched? Could well be a health and safety issue.

 

[ban-all-sheds]

They look very similar to the lights I have in my front garden - I wonder how long it will be before the plastic diffuser starts to discolour from the heat of the incandescent lamps?

 

[ricicle]

To the OP:-

Are these wall lights the main source of illumination in these offices ?
I can't believe that they would provide anywhere near the required level and type of light required for offices and is even worse considering the amount of energy required to run them.

 

[skotl]

Thanks for all the excellent replies.

These are primarily used in the smaller rooms and in the stairs and halls - the larger offices have flourescents.

Eric mentioned that corporate lights need to look good but, with 50% of them blown at any time, they defo don't look good right now!
And BAS mentioned £2k p.a. for 5 days at 10 hours a day.... the offices are 24x7!!

To be honest, I may not know too much about this stuff, but I was still astonished when I decided to investigate why they were blowing so often and found the pairs of 70W in every light!
I've already ordered 60 x 27W low energy bulbs. As you can imagine, I don't see any point in going back to the original electrician.

Cheers for the responses, folks.