School lighting job

[L-E_Fault]

I'm working on a school tomorrow and I'm after a bit of advise on how to approach the job. I have exsiting lighting which needs to be moved and changed. The new lights have to be controlled by pir's and need to be switch-able. The exsiting lights are run in steel conduit above the ceiling, each ceiling has a small access hatch.

Oh and I need to run some dado trunking, but on the one wall it has a boxing that protrudes 35mm, how do I get over that??

Tim

 

[kme]

OK.

The question.........?

KME

 

[L-E_Fault]

how do I tap off the conduit above the ceiling?

 

[kme]

Well:

As you`ve got to move the lights, you can fit a 3 way box onto the end of the existing; take 1 way to the new light position, and the other to your "occupancy switch".

As for the boxwork - what is it concealing? Are there pipes there? If so, you`d have to go around it, or stop to one side and restart the other side (not useful if you`ve got services in the dado!). If you`re using the MK type dado, they do internal and external corners - you`d have to come out & round the box.

HTH

KME

 

[M107]

Not seeing the job is a bit of a disadvantage but...

Remove the light you are needing to move. Fit a one way + rear entry besa box to the tube (where light was), if the box is in the right place you could fit a 360deg pir to the box (not forgetting to pull in a perm line).

Run new tube from the besa box to where you are relocating the light.

The dado trunk thats a nightmare you'll have to fiddle about at.

 

[Lee321]

the dado you will have to mitre because obviously an internal and external are more than 35mm. pack the back with a piece of wood.

i can give you all the EXACT measurements & cuts needed if you like

i just need the depth of the dado

 

[kme]

There was a thread showing them, not long back - started with metal trunking.........

Can`t recall who it was, though?

 

[Lee321]

There was a thread showing them, not long back - started with metal trunking.........Can`t recall who it was, though?

:_|

 

[Lee321]

this should be to scale too

for it to be pukka you need a table saw

 

[oldtimespark]

Hi so the cut angle on the saw is inverse Tan =opposite/adjacent 10/75=0.13333333333333333333333333333333=7.5946336859144 degrees.

Long time since I did trigonometry .

 

[Badger]

Hi so the cut angle on the saw is inverse Tan =opposite/adjacent 10/75=0.13333333333333333333333333333333=7.5946336859144 degrees.Long time since I did trigonometry .

:_| :_| :_| :run :run

 

[oldtimespark]

Laugh, and the world laughs with you;

Weep, and you weep alone.

 

[L-E_Fault]

ok the conduit box is flush with the ceiling and they don't want any thing surface mounted, any ideas?

As far as the perm live am I right in thinking I can just come of the loop at the light or is it better to pull in a single brown?

 

[Lee321]

turn the box round facing into the loft. fit a plug in ceiling rose and flex to the new position Guinness

builder to fill the old hole

 

[oldtimespark]

Permanent live may not be present at light fittings on a conduit job.

It is common practise to take the feed straight to the switch position.

What is the make of the PIR Occupancy Sensor ?

 

[Lee321]

hope you've allowed plenty of time.

wiring old conduit systems can be a time zapper

 

[L-E_Fault]

[quote name='Lee

 

[Lee321]

is there a spare knockout or space to get a 20mm hole in the back?

 

[L-E_Fault]

nope

 

[Lee321]

rubbish you haven't looked :Blushing

you only need 1 to "break" into the conduit wiring system then your away.

could even fit a multi click box job done