SYSTEM OPERATION
29
ELECTRIC HEATERS
Optional electric heaters may be added, in the quantities
shown in the specifications section to provide electric resis-
tance heating. Under no condition shall more heaters than
the quantity shown be installed.
The low voltage circuit in the blower section 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,
Outdoor Thermostat, and Compressor sound blankets are
available to complete the installation.
The system CFM can be determined by measuring the static
pressure external to the unit. The installation manual sup-
plied with the unit shows the CFM for the static measured.
Alternately, the system CFM can be determined by operat-
ing 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.
EXAMPLE:
Five (5) heaters provide 24.0 KW at the rated
240V. Our actual measured voltage is 220V, and our mea-
sured temperature rise is 42°F. Find the actual CFM:
Answer:
24.0 KW, 42°F Rise, 240 V = 1800 CFM from the
TEMPERATURE RISE
chart below.
Heating output at 220 V = 24.0 x 3.413 x .84 - 68.8 MBh.
Actual CFM = 1800 x .84 = 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 pres-
sure at a particular CFM will be less.
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 (
Δ
T)
CFM = KW x 3413
1.08 x
Δ
T
Δ
T = BTUH
CFM x 1.08
Heater Capacity @ 240 VAC
Heater Kit
kW BTUH
Minimum
Circuit
Ampacity
Maximum
Overcurrent
Protection
L1 - L2 L3 - L4 L1 - L2 L3 - L4
PHCB05C1
4.8 16,400
25
--
30
--
PHCB10C1
9.6 32,800
50
--
60
--
PHCB15C1 14.4 49,100
50
25
60
30
PHCB20C1 19.2 65,500
50
50
60
60
R
O
T
C
A
F
N
O
I
T
C
E
R
R
O
C
Y
T
I
C
A
P
A
C
H
U
T
B
E
G
A
T
L
O
V
Y
L
P
P
U
S
0
8
4
0
6
4
0
4
4
0
5
2
0
3
2
0
2
2
8
0
2
R
O
T
C
A
F
N
O
I
T
A
C
I
L
P
I
T
L
U
M
9
0
.
1
0
0
.
1
1
9
.
8
0
.
1
2
9
.
4
8
.
5
7
.
V
0
4
2
@
)
°
F
(
E
S
I
R
E
R
U
T
A
R
E
P
M
E
T
M
F
C
8
.
4
.
W
.
K
2
.
7
.
W
.
K
6
.
9
.
W
.
K
4
.
4
1
.
W
.
K
2
.
9
1
.
W
.
K
0
.
4
2
.
W
.
K
8
.
8
2
.
W
.
K
0
0
6
5
2
8
3
1
5
-
-
-
-
0
0
7
2
2
3
3
3
4
-
-
-
-
0
0
8
9
1
9
2
8
3
7
5
-
-
-
0
0
9
7
1
6
2
4
3
1
5
-
-
-
0
0
0
1
5
1
3
2
0
3
6
4
-
-
-
0
0
1
1
4
1
1
2
7
2
1
4
5
5
-
-
0
0
2
1
3
1
9
1
5
2
8
3
0
5
-
-
0
0
3
1
2
1
8
1
3
2
5
3
6
4
-
-
0
0
4
1
1
1
6
1
2
2
2
3
3
4
4
5
5
6
0
0
5
1
0
1
5
1
0
2
0
3
0
4
0
5
0
6
0
0
6
1
9
4
1
9
1
8
2
8
3
7
4
7
5
0
0
7
1
9
4
1
8
1
7
2
6
3
4
4
3
5
0
0
8
1
8
3
1
7
1
5
2
4
3
2
4
0
5
0
0
9
1
8
2
1
6
1
4
2
2
3
0
4
8
4
0
0
0
2
8
2
1
5
1
3
2
0
3
8
3
5
4
0
0
1
2
7
1
1
4
1
2
2
9
2
6
3
3
4
0
0
2
2
7
1
1
4
1
1
2
7
2
4
3
1
4
0
0
3
2
7
0
1
3
1
0
2
6
2
3
3
9
3
