IET logo
Decrease font size
Increase font size
Topic Summary: Approx distance between fittings
Created On: 21 January 2008 08:38 PM
Status: Read Only
Linear : Threading : Single : Branch
<< 1 2 Previous Last unread
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 23 January 2008 06:47 PM
User is offline View Users Profile Print this message


Posts: 22467
Joined: 23 March 2004

Originally posted by: perspicacious

"Will try and probe him further"

Nick, I think he's already done that to you





Let the wind blow you, across a big floor.
 11 November 2017 02:19 AM
User is offline View Users Profile Print this message


Posts: 269
Joined: 01 April 2006

Originally posted by: markLEDS

You need to ask the lighting designer, it will depend on the type of luminaire used, ceiling heights etc.

Ask him what the centre to centre distance is of the luminaires. If they say 2.4m then its 3 tiles apart. If they say 3m then it's 4 tiles. Both are fairly standard spacings but it will depend on the characteristics of the luminaires and the lighting level they are trying to achieve.


I was faced with the unfortunate situation of providing LED luminaires for an empty shell which the client was desperate to fit-out for offices. As we had no architectural drawings from the client, the architect had to come to site to assess the empty shell area.

Because of the urgency and eagerness by the client to start the work, I had to estimate the number of LED luminaires required. This turned out to be much fewer than what was actually required which meant that it was under-costed. Had I waited for the suspended ceiling plan to come back from the architect showing the height of the suspended ceiling with the ceiling grid and sent this out to the lighting designer for pricing, the outcome would have been a lot different.

A one-off costly error of judgement which resulted in a loss and a lesson I certainly never want to repeat.

Is there a better approach? I'm certainly open to suggestions.

Basil Wallace PgDip MIET EngTech

Edited: 11 November 2017 at 12:01 PM by basil.wallace
 12 November 2017 08:41 AM
User is offline View Users Profile Print this message


Posts: 3535
Joined: 20 February 2014

Those 2 X 55W compact fluorescent fittings are very bright and run quite warm in use, even with electronic ballasts. They also seem to be "handed" regarding the light output, so correct positioning is essential. The reflector tapers from one side to the lamps' side. They are great for places like hairdressers or retail chemists shop etc. I am not sure if they are suitable for offices as they are very bright sources of light and may cause discomfort. The electronic ballasts have automatic over current and over temperatue cut off facilities. Normally each luminaire has an internal fuse in its terminal block.


 13 November 2017 12:39 PM
User is offline View Users Profile Print this message


Posts: 269
Joined: 01 April 2006

I would advise looking at Building Regulations, specifically part B was well as TP (a) and (B) ratings. Typically TP (a) etc. applies on suspended ceiling systems where diffuser is flush with suspended ceiling.

This may help:

Basil Wallace PgDip MIET EngTech

Edited: 13 November 2017 at 04:13 PM by basil.wallace
IET » Wiring and the regulations » SUSPENDED CEILING LIGHTING LAYOUT

<< 1 2 Previous Last unread
Topic Tools Topic Tools

New here?

See Also:

FuseTalk Standard Edition v3.2 - © 1999-2018 FuseTalk Inc. All rights reserved.