SERVICING
47
S-60 ELECTRIC HEATER (OPTIONAL ITEM)
Optional electric heaters may be added, in the quantities shown
in the specifications section, to provide electric resistance heat-
ing. Under no condition shall more heaters than the quantity
shown be installed.
The low voltage circuit in the air handler is factory wired and
terminates at the location provided for the electric heater(s). A
minimum of field wiring is required to complete the installation.
Other components such as a Heating/Cooling Thermostat and
Outdoor Thermostats are available to complete the installation.
The system CFM can be determined by measuring the static pres-
sure external to the unit. The installation manual supplied with
the blower coil, or the blower performance table in the service
manual, shows the CFM for the static measured.
Alternately, the system CFM can be determined by operating the
electric heaters and indoor blower WITHOUT having the compres-
sor in operation. Measure the temperature rise as close to the
blower inlet and outlet as possible.
If other than a 240V power supply is used, refer to the
BTUH CA-
PACITY CORRECTION FACTOR
in the following chart.
BTUH CAPACITY CORRECTION FACTOR
SUPPLY VOLTAGE
250
230
220
208
MULTIPLICATION FACTOR
1.08
.92
.84
.75
EXAMPLE:
Five (5) heaters provide 24.0 KW at the rated 240V. Our
actual measured voltage is 220V, and our measured temperature
rise is 42°F. Find the actual CFM:
Answer:
24.0KW, 42°F Rise, 240 V = 1800 CFM from the
TEMPERA-
TURE RISE
chart on the right.
Heating output at 220 V = 24.0KW x 3.413 x .84 = 68.8 MBH.
Actual CFM = 1800 x .84 Corr. Factor = 1400 CFM.
NOTE:
The temperature rise table is for sea level installations.
The temperature rise at a particular KW and CFM will be greater
at high altitudes, while the external static pressure at a particular
CFM will be less.
3
5
6
8
10
15
19/20
25
800
12
19
23
31
37
1000
9
15
19
25
30
44
1200
8
12
15
21
25
37
49
62
1400
7
11
13
18
21
32
42
53
1600
6
9
12
15
19
28
37
46
1800
5
8
10
14
16
25
33
41
2000
5
7
9
12
15
22
30
37
CFM
HEAT KIT NOMINAL kW
230/1/60 Supply Voltage - Temp. Rise °F
3
5
6
8
10
15
19/20
25
800
11
18
22
30
35
1000
9
14
18
24
28
42
1200
7
12
15
20
24
35
47
59
1400
6
10
13
17
20
30
40
51
1600
6
9
11
15
18
27
35
44
1800
5
8
10
13
16
24
31
39
2000
4
7
9
12
14
21
28
35
CFM
HEAT KIT NOMINAL kW
220/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
3
5
6
8
10
15
19/20
25
800
10
17
21
28
33
1000
8
13
17
22
27
40
1200
7
11
14
19
22
33
45
56
1400
6
10
12
16
19
29
38
48
1600
5
8
10
14
17
25
33
42
1800
5
7
9
12
15
22
30
37
2000
4
7
8
11
13
20
27
33
CFM
HEAT KIT NOMINAL kW
208/1/60 SUPPLY VOLTAGE - TEMP. RISE °F
HTR
KW
3.0
KW
4.7
KW
6.0
KW
7.0
KW
9.5
KW
14.2
KW
19.5
KW
21.0
KW
BTUH 10200 16200 20400 23800 32400 48600 66500 71600
ELECTRIC HEATER CAPACITY BTUH
FORMULAS:
Heating Output = KW x 3.413 x Corr. Factor
Actual CFM = CFM (from table) x Corr. Factor
BTUH = KW x 3.413
BTUH = CFM x 1.08 x Temperature Rise (T)
CFM = KW x 3.413
1.08 x T
T = BTUH
CFM x 1.08
