SERVICING
76
5.3 The system operates at emergency heat.
5.4 Once the thermostat demand is satisfied, the CTK0*
thermostat commands the air handler/modular blower to
end emergency heat operation. The air handler control
de-energizes the electric heat sequencer outputs. The
ECM blower motor remains energized until any blower
OFF delay timing has expired. energizes the variavble
speed ECM motor at fan demand provided by the thermo-
stat. The fan demand provided by the thermostat will be
30%, 50%,or 70% of the air handler's maximum airflow
capability. The continuous fan demand is set from the
thermostat as low, medium, or high.
S-60 ELECTRIC HEATER (OPTIONAL ITEM)
Optional electric heaters may be added, in the quantities
shown in the specifications section, to provide electric
resistance heating. 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 instal-
lation.
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
pressure 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 mea-
sured.
Alternately, the system CFM can be determined by operating
the electric heaters and indoor blower WITHOUT having the
compressor 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
CAPACITY CORRECTION FACTOR
chart below.
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
TEMPERATURE 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 installa-
tions. 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.
CFM
3.0
kW
4.8
kW
7.2
kW
9.6
kW
14.4
kW
19.2
kW
24.0
kW
28.8
kW
600
16
25
38
51
-
-
-
-
700
14
22
33
43
-
-
-
-
800
12
19
29
38
57
-
-
-
900
11
17
26
34
51
-
-
-
1000
10
15
23
30
46
-
-
-
1100
9
14
21
27
41
55
-
-
1200
8
13
19
25
38
50
-
-
1300
7
12
18
23
35
46
-
-
1400
7
11
16
22
32
43
54
65
1500
6
10
15
20
30
40
50
60
1600
6
9
14
19
28
38
47
57
1700
6
9
14
18
27
36
44
53
1800
5
8
13
17
25
34
42
50
1900
5
8
12
16
24
32
40
48
2000
5
8
12
15
23
30
38
45
2100
5
7
11
14
22
29
36
43
2200
4
7
11
14
21
27
34
41
2300
4
7
10
13
20
26
33
39
TEMP ERATURE RISE (°F) @ 240V
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
