York ZZ Seies, Installation Manual

Page: 25 / 62

5835254-YIM-A-1119
Johnson Controls Ducted Systems 25
Optional electric heat
The factory-installed heaters are wired for single point power
supply. You only need to bring the power supply 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. See Table 12 for
minimum CFM limitations. See Table 10 for electrical data.
Optional gas heat
The optional gas-fired heaters have aluminized-steel or optional
stainless steel, tubular heat exchangers with spark ignition.
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.
Follow the “National Fuel Gas Code” Z223.1 (in U.S.A.) or the
current Gas Installation Codes CSA-B149.1 (in Canada) in all
cases unless they are superseded by local codes or gas utility
requirements.
See Table 13,
Gas pipe sizing - capacity of pipe,
on page 25.
The heating value of the gas may vary by locality. You must
check the value with the local gas utility.
Figure 23: Side entry gas piping
Figure 24: Bottom entry gas piping
Table 12: Electric heat minimum supply air
Size (tons) Model Voltage
Minimum supply air (CFM)
Heater kW
9 18 24 36 54
15
(15)
ZZ
208/230-3-60 - 3750 3750 3750 4000
460-3-60 - 3750 3750 3750 3750
OPTIONAL
COIL
GUARD
SHOWN
Table 13: Gas pipe sizing - capacity of pipe
Length of
pipe (ft.)
Nominal iron pipe size
3/4 in. 1 in. 1-1/4 in.
10 278 520 1050
20 190 350 730
30 152 285 590
40 130 245 500
50 115 215 440
60 105 195 400
70 96 180 370
80 90 170 350
90 84 160 320
100 79 150 305
OPTIONAL
COIL
GUARD
SHOWN