Designing a Lighting Layout

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Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
How do you go about designging a lighting layout for an empty space/building? i remember reading a book years ago where they talked about the calculated load and connected load, volt amps etc. THanks.
 

jumper

Senior Member
How do you go about designging a lighting layout for an empty space/building? i remember reading a book years ago where they talked about the calculated load and connected load, volt amps etc. THanks.

For the service you use the higher of either the actual connected load or the minimum in T220.12.

Branch circuits are based on connected load.
 

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
For the service you use the higher of either the actual connected load or the minimum in T220.12.

Branch circuits are based on connected load.

Thanks...how is calculated and connected loads figured and arent there guidleines somewhere as to the limits in certains areas? THanks.
 

jumper

Senior Member
Quick scenario: Empty store. 2000 sq ft. Owner buys 20 200w fixtures. Service load.

Calculated Load
T 220.12, 2000x3w=6000w, Demand factor T220.42= 100%. Continuous Load 6000 x 125%=7500w

Connected Load
20 x 200w =4000, 100% demand x 125% continuous. 5000w.

Service load=7500w, higher of the 2.
 

Alwayslearningelec

Senior Member
Location
NJ
Occupation
Estimator
Quick scenario: Empty store. 2000 sq ft. Owner buys 20 200w fixtures. Service load.

Calculated Load
T 220.12, 2000x3w=6000w, Demand factor T220.42= 100%. Continuous Load 6000 x 125%=7500w

Connected Load
20 x 200w =4000, 100% demand x 125% continuous. 5000w.

Service load=7500w, higher of the 2.

Thanks a lot.
 

JeffD

Member
Location
cleveland, oh
Lighting design is more complicated than it used to be because of the energy codes. You might just want to get a supplier or manufacturer to look at it and have them design it for you and you buy their fixtures. Just make you check their cost to keep them in line. Lithonia and Metalux used to have a program on line that would also do it for you and then provide cut sheets of the fixtures used. Not sure if it is still out there or not.
 
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cyriousn

Senior Member
Location
ME / CT
Occupation
EE & BIM
Footcandles

Footcandles

The Illuminating Engineering Society has recommended footcandle levels to follow for different applications based on the visual tasks the space will be used for. National and state codes can dictate the minimum footcandles needed in areas such as egress areas for emergencies. Additionally, the energy codes such as ASHRAE 90.1 and IECC will tell you the maximum amount of energy you are allowed to use in a specific type of space. Most commerical buildings are only allowed to use around 1 watt/sq.
 
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