User Guide

This quick calculator chart determines the number and spacing of 150 Watt A-23 units for any desired level of
illumination. For 200 Watt A-23 units, multiply chart values by 1.4.
80% Ceiling; 50% Walls; 20% Floor
Room Surface Reflectances:
150W A-23
2730 Lumens Per Lamp
RCR = 10 (Rm. Width - Mtg. Ht. above work plane)
RCR = 5 (Rm. Width - 2 x Mtg. Ht. above work plane)
RCR = 1 (Rm. Width - 10 x Mtg. Ht. above work plane)
CENTER TO CENTER DISTANCE OF FIXTURES IN FEET
AREA PER FIXTURE IN SQUARE FEET
INITIAL FOOTCANDLES
3 4 5 6 7 8 9 10 11 12
25 50 75 100 125
10
20
30
40
50
60
COEFFICIENTS OF UTILIZATION
%
EFFECTIVE CEILING CAVITY REFLECTANCE
80 70 50 30 10 0
ROOM CAVITY RATIO
20% FLOOR CAVITY REFLECTANCE
50 30 10 50 30 10 50 30 10 50 30 10 50 30 10 0
.53 .52 .51 .52 .51 .51 .50 .50 .49 .48 .48 .48 .47 .47 .46 .45
.51 .49 .48 .50 .48 .47 .48 .47 .46 .47 .46 .45 .46 .45 .44 .44
.48 .47 .45 .48 .46 .45 .47 .45 .44 .45 .44 .43 .44 .44 .43 .42
.46 .44 .43 .46 .44 .42 .45 .43 .43 .44 .42. 41 .43 .42 .41 .40
.44 .42 .40 .44 .41 .40 .43 .41 .40 .42 .40 .39 .40 .40 .39 .38
.42 .40 38. 42 .40 .38 .41 .39 .38 .40 .39 .38 .40 .38 .37 .37
.40 .38 .36 .40 .38 .36 .39 .37 .36 .39 .37 .36 .38 .37 .36 .35
.38 .36 .34 .38 .36 .34 .37 .35 .34 .37 .35 .34 .36 .35 .34 .33
.36 .34 .32 .36 .34 .32 .36 .34 .32 .35 .34 .32 .35 .33 .32 .32
.35 .32 .31 .35 .32 .31 .34 .32 .31 .34 .32 .31 .34 .32 .31 .30
1
2
3
4
5
6
7
8
9
10
% WALL REFLECTANCE
Conversion Factor:
300
600
90
60
30
900
1200
E.T.L, Inc. report No. 389989
Date: 04-17-64
Efficiency: 47.5%
Spacing Ration = 1.1
150W A23
2700 Lumens Per Lamp
DEG CP ZONAL FLUX
2 1/2 1279 31
7 1/2 1257 90
12 1/2 1249 148
17 1/2 1335 220
22 1/2 1287 270
27 1/2 1097 278
32 1/2 646 190
37 1/2 137 46
42 1/2 25.6 9
47 1/2 5.5 2
52 1/2 0 0
Candlepower Summary
ZONE LUMENS % LAMP
0-30 1037 38.5
0-40 1273 47.0
0-60 1284 47.5
Lightolier a Genlyte Thomas Company www.lightolier.com
631 Airport Road, Fall River, MA 02720 • [phone] • Fax [phone]
We reserve the right to change details of design, materials and finish.
© 2002 Genlyte Thomas Group LLC (Lightolier Division) • A0902
Job Information Type:
Calculite
®
Incancescent Open Downlight 784/7784
Page 2 of 2 6” Aperture A23 Ellipsoidal Reflector