160 foot wall...

Status
Not open for further replies.

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
I have a customer who would like to use motion sensor lights to illuminate an exterior wall of his business. I was thinking a two head motion sensor with 90w lamps. I'm not sure what the light spread of a 90w lamp would be. My question is how many lights and how far apart should they be. Lights can be mounted about 10 to 12'.

Thanks
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I have a customer who would like to use motion sensor lights to illuminate an exterior wall of his business. I was thinking a two head motion sensor with 90w lamps. I'm not sure what the light spread of a 90w lamp would be. My question is how many lights and how far apart should they be. Lights can be mounted about 10 to 12'.

Thanks

Just from looking at my own setup, I would say about 6 lights.
 

cadpoint

Senior Member
Location
Durham, NC
Why are you going with motion, it seems that would time out?

Why not go with photo eyes or a time clock?

This has to be an unusual application where a business owner wants it lite and then not want it lite... can you elaborate?
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
It depends on what the function of the light is and where you start them. I can easily see a 90 watt bulb illuminate 15'. So set 2 flood 15' from both ends. Now even space 3 fixtures between that every 30' or so.

Again how much light is needed? Security? Walkway? etc
 

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
Why are you going with motion, it seems that would time out?

Why not go with photo eyes or a time clock?

This has to be an unusual application where a business owner wants it lite and then not want it lite... can you elaborate?

Business is out in an Industrial type area. They were broken into one night by robbers breaking through the cinder block wall. Owner asked for motion lights, I guess so they only burn when someone happens to be luring around. Motion might startle would be "Evildoers".
 

Attachments

  • IMG_1204-2.jpg
    IMG_1204-2.jpg
    42.8 KB · Views: 0
The standard two-head motion fixture is very vulnerable to vandalism. Any "evildoer" who wants in through the wall isn't going to be deterred by those lights - a simple pellet gun will take care of them.

Don't know what the budget is, but I'd go with some vandal-proof MH fixtures mounted on the wall as high as practical, and a proper security system inside. If the owner squawks about it, ask them what the cost of another break-in is as compared to good lighting and security.

Crooks hate lights, cops love 'em.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Business is out in an Industrial type area. They were broken into one night by robbers breaking through the cinder block wall. Owner asked for motion lights, I guess so they only burn when someone happens to be luring around. Motion might startle would be "Evildoers".

Or help them see what they are doing........A couple of German Sheperds unrestrained inside the building would be a better solution, once they got in, they would not want to come back. Pick them up at the local hospital after the Sheperds got through with them!:lol:
 

cadpoint

Senior Member
Location
Durham, NC
If there coming through the walls, I'd hang and get some lights burning.

I'd also consider an upsale with some kind of interactive internal security(.)
 
Last edited:

Smart $

Esteemed Member
Location
Ohio
Do you think that 3 would be sufficient?
There's no way to determine the exact number of fixtures without knowing the fixture, lamp, minimum illumination desired, in addition to the mounting height and the area (which you have provided). Take for example using flood lamp fixtures... A fllood lamp's beam angle can vary from say 30? to 60? while the lumen output may or may not remain the same for the same wattage lamp. Then you have to consider the falloff from the beam's center... i.e. dimmer on the outer area while brighter in the center. Overlap may be necessary, which defeats attempting to use a wider beam lamp and less fixtures.

To do it right, you will have to determine or otherwise set the minimum illumination level at various points being illuminated. Then you will have to determine a fixture, lamp, wattage, mounting height combination that will provide that amount of illumination. Anything short of this will be just a shot in the dark (pun intended)...
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
You can always call a company like this and see what their engineers recommend. Ruud Lighting offers free design support.

http://www.ruudlightingdirect.com/

Application Engineers Help Resolve Your Lighting Challenges
Our Applications staff can recommend the luminaire best suited for your specific application and can provide a professionally prepared lighting layout at no additional cost. Contact our Application Engineering Team by calling (800) 236-7000, Monday through Friday, 7:00 a.m. to 5:00 p.m. (CT).
 

WIMaster

Senior Member
Location
Wisconsin
Motion lights and an alarm will help to deter them and alert others.
GOOD video will help to catch them.

If they are breaking through a block wall I would try to sell at least an alarm system. These folks figure they have plenty of time to go about their "business" without anyone knowing.
 

1793

Senior Member
Location
Louisville, Kentucky
Occupation
Inspector
Motion lights and an alarm will help to deter them and alert others.
GOOD video will help to catch them.

If they are breaking through a block wall I would try to sell at least an alarm system. These folks figure they have plenty of time to go about their "business" without anyone knowing.

They do have a video camera located at one end of the building, however it does not cover the entire wall space. I think they are talking about a second camera and the lighting would be beneficial.
 

BullsnPyrs

Senior Member
Consider the camera when selecting a light source. HPS is notoriously poor for identification quality photos/video. MH or LED is a much better source when used with cameras. Cooper has some LED fixtures that might work well in this application. A couple of streetlighter fixtures mast mounted to increase the mounting height might do the job. One advantage of the Cooper LED fixture is that each LED has it's own optics, a criminal would have to shoot out each LED or hit every driver to eliminate light. The fixtures are built using a modular design so individual light bars and drivers can be replaced.
 

broadgage

Senior Member
Location
London, England
Whatever lightsource is selected, consider an alarm that is triggered by any significant reduction in the current drawn by the lights. This will give warning if the lamps are shot at or otherwise disabled.
 
Status
Not open for further replies.
Top