Johnson Controls ZY Series - Page 79

Table 26: Gas Heat Supply Air
Supply Air (CFM)
Heating
Model
(Size)
Gas Heat
Description
Opt.
Min Max
Low, NOx L 900 1480
Low D 890 1480
Med, NOx M 900 1520
ZY04 (3)
Med E 1060 1510
Low, NOx L 1190 1980
Low D 1210 1990
Med, NOx M 1190 2020
Med E 1200 2020
High, NOx N 1200 1990
ZY05 (4)
High F 1390 2190
Low, NOx L 1480 2440
Low D 1480 2470
Med, NOx M 1520 2470
Med E 1510 2510
High, NOx N 1510 2500
ZY06 (5)
High F 1490 2500
Med E 1820 2990
ZY07 (6)
High F 1790 3000
Med E 1820 2990
ZYA7 (6)
High F 1790 3000
Low D 2260 3700
Med E 2260 3700
ZY08
(7.5)
High F 2260 3790
Low D 2570 4210
Med E 2560 4300
ZY09
(8.5)
High F 2550 4290
Low D 3030 4940
Med E 3020 4940
ZY12 (10)
High F 2990 5010
Gas connection
About this task:
The gas supply line can be routed within the
space and roof curb, exiting through the unit’s
basepan. Refer to Figure 11 through Figure 15 for
the gas piping inlet location. Typical supply piping
arrangements are shown in Figure 24. All pipe
nipples, fittings, and the gas cock are field supplied.
Gas piping recommendations:
1. A drip leg and a ground joint union must be
installed in the gas piping.
2. Where required by local codes, a manual shut-
off valve must be installed outside of the unit.
3. Use wrought iron or steel pipe for all gas lines.
Pipe dope should be applied sparingly to male
threads only. If local codes allow the use of a
flexible gas appliance connector, always use a
new listed connector. Do not use a connector
which has previously serviced another gas
appliance.
WARNING
Natural gas may contain some propane. Propane is
an excellent solvent and will quickly dissolve white
lead and most standard commercial compounds. A
special pipe dope must be used when assembling
wrought iron or steel pipe. Shellac based compounds
such as Gaskolac or Stalastic, and compounds such
as Rectorseal #5, Clydes’s or John Crane may be
used.
4. All piping should be cleaned of dirt and scale
by hammering on the outside of the pipe
and blowing out loose particles. Before initial
start-up, be sure that all gas lines external to
the unit have been purged of air.
5. The gas supply should be a separate line and
installed in accordance with all safety codes as
prescribed under “Limitations”.
6. A 1/8-inch NPT plugged tapping, accessible
for test gauge connection, must be installed
immediately upstream of the gas supply
connection to the unit.
7. After the gas connections have been
completed, open the main shut-off valve
admitting normal gas pressure to the mains.
Check all joints for leaks with soap solution or
other material suitable for the purpose. NEVER
USE A FLAME.
WARNING
FIRE OR EXPLOSION HAZARD
Failure to follow the safety warning exactly could
result in serious injury, death or property damage.
Never test for gas leaks with an open flame. Use
a commercially available soap solution made
specifically for the detection of leaks to check all
connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
INSTALLATION MANUAL ZY SERIES 3-10ton 60 Hertz R-410A 79
Johnson Controls Ducted Systems