Lightolier 784/7784 Fascicule
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.
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
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 CA
VITY RA
TIO
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
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
Date: 04-17-64
Efficiency: 47.5%
Spacing Ration = 1.1
150W A23
2700 Lumens Per Lamp
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 • (508) 679-8131 • Fax (508) 674-4710
We reserve the right to change details of design, materials and finish.
© 2002 Genlyte Thomas Group LLC (Lightolier Division) • A0902
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