67
SERVICING
HIGH VOLTAGE!
Disconnect ALL power before servicing
or installing. Multiple power sources
may be present. Failure to do so may
cause property damage, personal injury
or death.
1. Disassemble and remove the heating element(s).
2. Visually inspect the heater assembly for any breaks in the
wire or broken insulators.
3. Using an ohmmeter, test the element for continuity - no
reading indicates the element is open. Replace as necessary.
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
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 measured.
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 following
BTUH CAPACITY CORRECTION FACTOR
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 tem
-
perature 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 installations.
The temperature rise at a particular KW and CFM will be greater
at high altitudes, while the external static pressure at a particu
-
lar 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
TEMPERATURE 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
FORMULAS:
Heating Output = KW x 3413 x Corr. Factor
Actual CFM = CFM (from table) x Corr. Factor
BTUH = KW x 3413
BTUH = CFM x 1.08 x Temperature Rise (T)
CFM = KW x 3413
1.08 x T
T = BTUH
CFM x 1.08
S-61A CHECKING HEATER LIMIT CONTROL(S)
Each individual heater element is protected with a limit control
device connected in series with each element to prevent over
-
heating of components in case of low airflow. This limit control
will open its circuit at approximately 150°F.
Содержание DAR09
Страница 59: ...59 SERVICING Table 1 Quick Reference Table...
Страница 81: ...81 AIRHANDLERS...
Страница 96: ...96 REM OTE SPLITS...