Goodman [A/G]PG, Инструкция по эксплуатации

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SERVICING
48
In checking main burners, look for signs of rust, oversized and
undersized carry-over ports restricted with foreign material, etc.
S-306 CHECKING ORIFICES
A predetermined fixed gas orifice is used in all of these pack-
age gas units. That is an orifice which has a fixed bore and
position.
A
GAS
STREAM B
DENT OR
BURR
GAS
STREAM B
The length of Dimension "A" determines the angle of Gas Stream
Defraction, "B".
A dent or burr will cause severe deflection of gas stream.
No resizing should be attempted until all factors are taken into
consideration such as inlet manifold gas pressure, alignment,
and positioning, specific gravity and BTU content of the gas
being consumed.
The only time resizing is required is when a reduction in firing
rate is required for an increase in altitude.
Orifices should be treated with care in order to prevent dam-
age. They should be removed and installed with a box-end
wrench in order to prevent distortion. Under no circumstances
should an orifice be altered. Altering the orifice will change the
angle or deflection of the vacuum effect or entraining of primary
air, making it difficult to adjust the flame properly. This same
problem can occur if an orifice spud of a different length is
substituted.
1. Check orifice visually for distortion and/or burrs.
2. Check orifice size with orifice sizing drills.
3. If resizing is required, a new orifice of the same physical
size and angle with proper drill size opening should be in-
stalled.
S-307 CHECKING GAS PRESSURE
Gas inlet and manifold pressures should be checked and ad-
justed in accordance to the type of fuel being consumed.
1. Connect a water manometer or adequate gauge to the inlet
pressure fitting of the gas valve.
2. Remove the pressure tap fitting at the manifold if provided
or check at the gas valve outlet fitting and connect another
manometer or gauge.
Pressure Regulator
Adjustment
(Under Cap Screw)
Gas Valve
On/Off
Selector
Switch
INLET
OUTLET
Inlet Pressure
Tap
Outlet Pressure
Tap
Open to
Atmosphere
Open to
Atmosphere
Inlet Pressure
Manifold
Pressure
MEASURING INLET AND MANIFOLD GAS PRESSURE
With Power ON:
Line Voltage now present.
3. Put the unit into heating cycle and turn on all other gas
consuming appliances.
For NATURAL GAS:
a. Inlet pressure should be a nominal 7" w.c.
b. Manifold pressure should be 3.5 ± .3"w.c.
(Canadian - Sea Level 4.2" ± .3" w.c.)