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1183875-YIM-A-1014
Johnson Controls Unitary Products
31
Optional Electric Heat
The factory-installed heaters are wired for single point power
supply. Power supply need only be brought into the single point
terminal block.
These CSA approved heaters are located within the central
compartment of the unit with the heater elements extending in
to the supply air chamber.
Fuses are supplied, where required, by the factory. Some kW
sizes require fuses and others do not. refer to Table 10 for
minimum CFM limitations and to Table 8 for electrical data.
Optional Gas Heat
These gas-fired heaters have aluminized-steel or optional
stainless steel, tubular heat exchangers with spark ignition.
NOTE:
On VAV units, individual VAV boxes must be fully open
in heating mode to insure airflow falls within specified
Temperature Rise range.
Gas Piping
Proper sizing of gas piping depends on the cubic feet per hour
of gas flow required, specific gravity of the gas and the length of
run. "National Fuel Gas Code" Z223.1 (in U.S.A.) or the current
Gas Installation Codes CSA-B149.1 (in Canada) should be
followed in all cases unless superseded by local codes or gas
utility requirements. Refer to the Pipe Sizing Table 11. The
heating value of the gas may differ with locality. The value
should be checked with the local gas utility.
Figure 25: Side Entry Gas Piping
Table 10: Electric Heat Minimum Supply Air
Size
(Tons)
Model
Voltage
Minimum Supply Air (CFM)
Heater kW
9
18
24
36
54
078
(6.5)
ZJ
208/230-3-60
1950
1950
1950
1950
-
460-3-60
1950
1950
1950
1950
-
600-3-60
1950
1950
1950
1950
-
090
(7.5)
ZJ
208/230-3-60
2250
2250
2250
2250
-
460-3-60
2250
2250
2250
2250
-
600-3-60
2250
2250
2250
2250
-
102
(8.5)
ZJ
208/230-3-60
2550
2550
2550
2550
-
460-3-60
2550
2550
2550
2550
-
600-3-60
2550
2550
2550
2550
-
120
(10)
ZJ
208/230-3-60
-
3000
3000
3000
3500
460-3-60
-
3000
3000
3000
3000
600-3-60
-
3000
3000
3000
3500
150
(12.5)
ZJ
208/230-3-60
-
3750
3750
3750
4000
460-3-60
-
3750
3750
3750
3750
600-3-60
-
3750
3750
3750
3750
OPTIONAL
COIL
GUARD
SHOWN