Goodmans CPG SERIES, Руководство по установке

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12
G
AS
P
IPING
C
HECKS
CAUTION
T
O PREVENT PROPERTY DAMAGE OR PERSONAL INJURY DUE TO FIRE, THE
FOLLOWING INSTRUCTIONS MUST BE PERFORMED REGARDING GAS
CONNECTIONS AND PRESSURE TESTING:
•
T
HE UNIT AND ITS GAS CONNECTIONS MUST BE LEAK TESTED BEFORE
PLACING IN OPERATION.
B
ECAUSE OF THE DANGER OF EXPLOSION OR
FIRE, NEVER USE A MATCH OR OPEN FLAME TO TEST FOR LEAKS.
N
EVER
EXCEED SPECIFIED PRESSURES FOR TESTING.
H
IGHER PRESSURE MAY
DAMAGE GAS VALVE AND CAUSE OVERFIRING WHICH MAY RESULT IN
PREMATURE HEAT EXCHANGE FAILURE.
•
T
HIS UNIT AND ITS SHUT-OFF VALVE MUST BE DISCONNECTED FROM
THE GAS SUPPLY DURING ANY PRESSURE TESTING OF THAT SYSTEM AT
TEST PRESSURES IN EXCESS OF 1/2
PSIG
(3.48 K
P
A).
•
T
HIS UNIT MUST BE ISOLATED FROM THE GAS SUPPLY SYSTEM BY
CLOSING ITS 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
(3.48 K
P
A).
WARNING
T
O AVOID PROPERTY DAMAGE OR PERSONAL INJURY
, BE SURE THERE IS
NO OPEN FLAME IN THE VICINITY DURING AIR BLEEDING.
There will be air in the gas supply line after testing for leaks
on a new installation. Therefore, the air must be bled from
the line by loosening the ground joint union until pure gas is
expelled. Tighten union and wait for five minutes until all gas
has been dissipated in the air. Be certain there is no open
flame in the vicinity during air bleeding procedure. The unit is
placed in operation by closing the main electrical disconnect
switch for the unit.
PROPANE GAS INSTALLATIONS
WARNING
T
O AVOID PROPERTY DAMAGE, PERSONAL INJURY OR DEATH DUE TO FIRE
OR EXPLOSION CAUSED BY A PROPANE GAS LEAK, INSTALL A GAS
DETECTING WARNING DEVICE.
S
INCE RUST CAN REDUCE THE LEVEL
OF ODORANT IN PROPANE GAS, A GAS DETECTING WARNING DEVICE
IS THE ONLY RELIABLE WAY TO DETECT A PROPANE GAS LEAK.
C
ONTACT A LOCAL PROPANE GAS SUPPLIER ABOUT INSTALLING A
GAS DETECTING WARNING DEVICE.
IMPORTANT NOTE: Propane gas conversion kits must be
installed to convert units to propane gas. NOx screens must
be removed before converting to LP. Remove burner
assembly and pull NOx screens from each burner tube. When
all the screens are out, reassemble the burner assembly
without the screens.
All propane gas equipment must conform to the safety
standards of the National Board of Fire Underwriters (See
NBFU Manual 58).
For satisfactory operation, propane gas supply pressure must
be within 9.7 - 10.3 inches W.C. at the manifold with all gas
appliances in operation. Maintaining proper gas pressure
depends on three main factors:
1. Vaporization rate, which depends on (a) temperature
of the liquid, and (b) wetted surface area of the
container or containers.
2. Proper pressure regulation.
3. Pressure drop in lines between regulators, and
between second stage regulator and the appliance.
Pipe size required will depend on length of pipe run
and total load of all appliances.
T
ANKS AND
P
IPING
Complete information regarding tank sizing for
vaporization, recommended regulator settings and pipe
sizing is available from most regulator manufacturers and
propane gas suppliers.
Since propane gas will quickly dissolve white lead or most
standard commercial compounds, special pipe dope
must be used. Shellac base compounds resistant to the
actions of liquefied petroleum gases such as Gasolac
®
,
Stalactic
®
, Clyde’s
®
or John Crane
®
are satisfactory.
See below for typical propane gas piping.
200 PSIG
Maximum
5 to 15 PSIG
(20 PSIG Max.)
Continuous
11" W.C.
Second Stage
Regulator
First Stage
Regulator
Typical Propane Gas Piping
R
OOF
T
OP
L
OCATION AND
I
NSTALLATION
The gas supply piping location and installation for roof top
units must be in accordance with local codes or, in the ab-
sence of locals codes, with ordinances of the latest edition of
the National Fuel Gas Code (ANSI Z223.1).
A manual gas shutoff valve must be field installed external to
the roof top unit. In addition, a drip leg must be installed near
the inlet connection. A ground joint union connection is re-
quired between the external shutoff valve and the unit con-
nection to the gas valve to permit removal of the burner as-
sembly for servicing.
1. Route gas piping to unit so that it does not interfere
with the removal of access panels. Support and align
piping to prevent strains or misalignment of the
manifold assembly.
2. All units are furnished with standard female NPT pipe
connections. Connection pipe sizes for CPG036
through 072 units is 1/2" NPT on 045 to 140 mBH
units. The size of the gas supply piping to the unit
must be based on length of run, number of units on
the system, gas characteristics, BTU requirement and
available supply pressure. All piping must be done in
accordance with local codes or, in the absence of local
codes, with the latest edition of the National Fuel Gas
Code (ANSI Z223.1).