Johnson Controls ZL Series Installation Manual page 44

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 in. 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.
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.
44 Installation Manual ZL Series 7.5- 12.5 Ton 60 Hertz R-410A
WARNING
WARNING
Johnson Controls Ducted Systems
The furnace and its individual shut-off valve
must be disconnected from the gas supply
piping system during any pressure testing at
pressures in excess of 1/2 psig. Pressures
greater than 1/2 psig will cause gas valve
damage resulting in a hazardous condition.
If it is subjected to a pressure greater than
1/2 psig, the gas valve must be replaced. The
furnace must be isolated from the gas supply
piping system by closing its individual manual
shut-off valve during any pressure testing of
the gas supply piping system at test pressures
equal to or less than 1/2 psig.
Threaded joints should be coated with a
sealing compound that is resistant to the action
of liquefied petroleum gases. Do not use
Teflon tape.
Check all connections for leaks when piping is
completed using a soap solution. Never use a
flame.
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.
Combustion air and flue
exhaust
Venting slots in the heating compartment access
panel remove the need for a combustion air hood.
The gas heat flue exhaust is routed from the unit
through a field installed exhaust hood with screen
CAUTION
WARNING
WARNING