Opinion on proposed new electric wiring for our ground floor.

[bbabythai]

We are renovating a building with intention of renting it out. The ground floor has 4m high ceilings and thus I bought 32 watt downlights. You can see them on the attach plan as DL. 24 of them. 

 

I will also put in spotlights - 2 at a time along the ceiling pointing down to provide more light. Perhaps a bit lower than the ceiling actually. 

 

My big question here is... I am going to ask the electrician to basically split the plan into 4 areas (A, B, C, D) and then put 1 switch in to control each sections downlights and 1 swtich for each sections Spot lights- both with the wire running back to its own breaker/ safety cut. Que 1: is this a good idea?

 

We had a problem in another location where the elec breaker was cutting due to overload apparantly.   I thus talked about this with the current technician and he said he would use special wire to prevent this. I wish I could remember the name of that wire. I see him tomorrow. Que 2: will such a wire prevent overload or whatever its called. Que 3: do you know what sort of wire it should be when each wire is effectively supporting 8 x 32 watt downlights. 

 

We have 4 x big size air cons. Que 4: does this require 5 wires?   Que 5. For a small air con on the 2nd floor is that a 2 or 3 wire requirement?

 

Re copper ground rod ouside in the earth.... Que 6: do they attach a wire to that rod which effectively runs to the big main elec box on the 2nd floor? Is this how it works?

 

many thanks

[Crossy]

How big is the area covered by your sketch? With that many 32W LEDs you may feel like a member of Trinity House (they operate the UK's lighthouses).

 

You may want to split into more smaller groups so you can control the light level by turning on/off specific areas.

 

Is the supply single or 3-phase. What size is the meter? (photos if you don't know)

 

That your A/C units are 5-wire suggests they are 3-phase, correct?

 

Do you have a photo of the breaker board you have / intend to use?

[bankruatsteve]

Q1 - It's OK but you don't really need 4 separate circuits.  Actually 2 or even 1 would be OK.

Q2 - Not likely to overload with 800 or so watts of lighting total.  Should use 1.5mm² wire on 10 amp breaker.

Q3 - Answered in Q2.

Q4 - L,N,E to each AC.  3 wires per AC.  This should be 2.5mm² on 20 amp breaker.

Q5 - Same as Q4.

Q6 - Yes if that is your primary CU on the 2nd floor.

[Crossy]

@bankruatsteve LEDs can have a very large inrush current, with that many I would be wanting at least 4 circuits with "C" curve MCBs.

 

 

[bankruatsteve]

11 minutes ago, Crossy said:

@bankruatsteve LEDs can have a very large inrush current, with that many I would be wanting at least 4 circuits with "C" curve MCBs.

Is there a given PF for LED lights or how would that be determined?  And, what is the typical start factor?  It does seem like lighting overkill to me but what would be the calculation?

[Crossy]

Just now, bankruatsteve said:

Is there a given PF for LED lights or how would that be determined?  And, what is the typical start factor?  It does seem like lighting overkill to me but what would be the calculation?

 

Interesting question about Power Factor (PF).

 

I've measured PF for a number of LEDs and CFLs and they range from ruddy awful (<0.4 or so) to better than 0.95. The common factor? Cost. Cheap Chinese units have no PF correction, the better Western sourced ones have active PF correction (required by regulation back home). None of the unit's I've bought mention what their PF actually is.

 

Like the PF the start surge can be extremely variable, I've not really looked in to it, but the better lamps have a series NTC that limits the inrush and gives a degree of soft start. Cheap lamps don't, so turning on at the peak of the mains cycle puts 350V across the uncharged filter capacitor with the current limited only by the rectifier.

 

For the lighting level, it depends upon the anticipated usage, if it's a shop or small manufacturing unit he could be about right.

 

[stouricks]

34 minutes ago, Crossy said:

How big is the area covered by your sketch? With that many 32W LEDs you may feel like a member of Trinity House (they operate the UK's lighthouses)

Yes, 24 downlighters are far too many. Will you put them on dimmers? 

Half that many plus a few recessed LED fittings would be much better.

And a couple of standard lamps in a corner somewhere.

[Crossy]

2 minutes ago, stouricks said:

Will you put them on dimmers? 

 

Sadly the units in question do not appear to be dimmable ????

 

[bbabythai]

3 hours ago, Crossy said:

How big is the area covered by your sketch? With that many 32W LEDs you may feel like a member of Trinity House (they operate the UK's lighthouses).

 

You may want to split into more smaller groups so you can control the light level by turning on/off specific areas.

 

Is the supply single or 3-phase. What size is the meter? (photos if you don't know)

 

That your A/C units are 5-wire suggests they are 3-phase, correct?

 

Do you have a photo of the breaker board you have / intend to use?

hi. 

 

A photo of the big elec box on our second floor is in this forum:

I would be buying a new smaller breaker box/ safety cut with 8 to 12 breakers from homepro for the ground floor stuff. 

 

With regards to the size of the floor space on the ground floor its 15m x 8m and 4.2m high

 

So do you still think I have too many 32watt downlights. The guy at homepro said the height of hte ceiling means that the downlights might not be that effective. Is that BS?

 

Should I cut down the downlights to 2 rows of 6 down lights?

 

Now Im wondering if I should put in the spotlights at all?

 

thanks

 

[BritManToo]

5 minutes ago, bbabythai said:

I would be buying a new smaller breaker box/ safety cut with 8 to 12 breakers from homepro for the ground floor stuff. 

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[sometimewoodworker]

6 hours ago, stouricks said:

Yes, 24 downlighters are far too many. Will you put them on dimmers? 

Half that many plus a few recessed LED fittings would be much better.

And a couple of standard lamps in a corner somewhere.

I have 50 lights on 5 switches + 14 down lights on another + 6 other lights on other switches in my medium sized living room/kitchen (probably around 700 watts LED)

 

So no 24 down lights is not excessive as long as the are able  to be switched in on different groups, though if they are all 32W units you may need sunglasses if they are all on.

 

installing more than enough means you always have enough even when some fail.

[kwak250]

I have no worthy comment just needed something to click to get me back to sleep .

Thanks

[Grusa]

19 hours ago, Crossy said:

Like the PF the start surge can be extremely variable, I've not really looked in to it, but the better lamps have a series NTC that limits the inrush and gives a degree of soft start. Cheap lamps don't, so turning on at the peak of the mains cycle puts 350V across the uncharged filter capacitor with the current limited only by the rectifier.

Ah! Is that why LED lights of any and all types suffer sudden random death, despite the "guaranteed" billion hours lifetime?

[bbabythai]

12 hours ago, sometimewoodworker said:

I have 50 lights on 5 switches + 14 down lights on another + 6 other lights on other switches in my medium sized living room/kitchen (probably around 700 watts LED)

 

So no 24 down lights is not excessive as long as the are able  to be switched in on different groups, though if they are all 32W units you may need sunglasses if they are all on.

 

installing more than enough means you always have enough even when some fail.

Thanks for your opinion on all this. 

 

If the area size is 15m x 8m and 4.2m high    do you think I should reduce the 2 rows of downlights from 8 to a row of 6??? or 7???   The spotlights on the side can be a backup. Both you and crossy are saying that it will be too bright. Thus I think making it 2 x rows of 6 AND    2 x rows of 3 on the left side of the plan (not 4 downlights)...

[bankruatsteve]

26 minutes ago, bbabythai said:

If the area size is 15m x 8m and 4.2m high

What will the area be used for?  As Crossy says, if for shop work or the like, you might be on target.  What will the spotlights be spotting?  Anyway... as long as you divide into sensible grids the light can be a lot or a little with the flip of switches.

[sometimewoodworker]

3 hours ago, bbabythai said:

Thanks for your opinion on all this. 

 

If the area size is 15m x 8m and 4.2m high    do you think I should reduce the 2 rows of downlights from 8 to a row of 6??? or 7???   The spotlights on the side can be a backup. Both you and crossy are saying that it will be too bright. Thus I think making it 2 x rows of 6 AND    2 x rows of 3 on the left side of the plan (not 4 downlights)...

Reduce the power of the lights rather than the number, your 32W LEDs are about 200W~250W incandescent each.

[bodga]

Before you start sticking in ANY LED's fit an over under voltage regulator in the  supply or  you'll be changing them every 10 minutes. I had 27  led's as outside lights, at best you would get 6-12 months out of  one, after I  fitted the regulator NONE  have failed , all were  good  brand names ie  Philips not cheap Chinese  ones, would  have thought 10watt  leds  would be more than enough

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