Electrical Requirements
44
CLCH-SVX009A-EN
Useful formulas:
kW = (Airflow x Delta T)/K
Delta T = (kW x K)/Airflow
K = 3145 (English)
K = 824.7 (SI)
Heater input current = (kW x 1000)/(Voltage x 1.73)
MCA = Minimum Circuit Ampacity
MOP = Maximum Overcurrent Protection rating or
Maximum fuse size
Fuse Sizes
The standard ampere ratings for fuses and inverse time
circuit breakers are listed in
Table 12
. The use of fuse and
inverse time circuit breakers with non-standard ampere
ratings shall be permitted provided the rating does not
exceed the maximum fuse size defined on the unit
nameplate.
Figure 39.
Interface power requirements
Table 10.
Electric heat voltage ratings
Unit Voltage
Heater Voltage
208
208
230
240
460
480
575
600
Line
voltage
24 Vac
Transformer
Termination board
Table 11.
Electric heat kW limits (min/max)
Motor
3
6
8
10
12
14
17
21
25
30
208 V / 60 Hz / 3 PH
6/13
6/26
7/28
8/41
10/50
12/50
14/50
17/50
20/47
20/41
230 V / 60 Hz / 3 PH
6/13
6/26
7/32
8/41
10/53
12/59
14/59
17/59
20/56
20/50
460 V / 60 Hz / 3 PH
6/13
6/24
7/32
8/44
10/53
12/63
14/75
17/95
20/95
20/120
575 V / 60 Hz / 3 PH
6/13
6/26
7/34
8/44
10/53
12/63
14/75
17/95
20/95
20/120
Min airflow (CFM)
1050
2100
2800
3500
4200
4900
5950
7350
8750
10,500
Notes:
Units drawing less than 100 amps are available with or without door interlocking disconnect. Units drawing more than 100 amps are not available
with door interlocking disconnect.
Units drawing less than 48 amps are available with or without line fusing. Units drawing greater than 48 amps have line fusing as standard.
Units with electric heat must not be run below the minimum cfm listed above.
Heaters available in the following kW increments: 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 41, 44, 47,
50, 53, 56, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 100, 110, 115, 120.
Table 12. Standard fuse sizes (amperes)
15
20
25
30
35
40
45
50
60
70
80
90
100
110
125
150
175
200
225
250
300
350
400
450
500
600
700
800
1000
1200 1600 2000 2500 3000 4000 5000 6000
