York YPAL 050 User Manual

Page of 168
54
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Startup
 • 
Check the supply pressure.  It must be within the 
limitations shown in Table 3-2.  Supply pressure 
should be checked with all gas appliances in the 
building at full fi re.  At no time should the standby 
gas pressure exceed 13.5" WC, nor the operating 
pressure drop below 4.5" WC for natural gas or 
11.0" WC for propane.  If the gas pressure is out-
side these limits, contact the installing mechanical 
contractor for corrective action.
 • 
The fl ame is stable, with fl ame present only at the 
end of the burner, no burning is occurring inside 
the burner.  There should be little yellow tipping 
of the fl ame.
 • 
There may be some smoke thru the fl ue, due to 
tooling oil burning off of the heat exchanger tub-
ing.
Manifold Gas Pressure Adjustment
 • 
Small adjustments to the manifold gas pressure 
can be made by following the procedure outlined 
below.  Refer to Figure 3-2 for the high and low 
fi re pressure regulator adjustment locations.
 • 
Turn the gas off to the unit.
 • 
Use a 3/16 inch Allen wrench to remove the 1/8 
inch NPT plug from the outlet pressure tap of the 
valve.
 • 
Install a brass adapter to allow the connection of 
a hose to the outlet pressure tap of the valve.
 • 
Connect the hose to a manometer capable of read-
ing the required manifold pressure value.
 • 
Turn the gas back on.
 • 
Place the heat section into high fi re operation.
 • 
Compare the high fi re manifold pressure to Table 
3-2. 
 • 
To adjust the high fi re manifold pressure remove 
the cap from the high fi re pressure regulator.  Use 
a 3/32 Allen wrench to make the manifold pressure 
adjustment.  To increase the manifold pressure, 
turn the screw clockwise; to decrease the manifold 
pressure, turn the screw counterclockwise.  Place 
your fi nger over the adjustment opening while 
verifying the manifold pressure.
 • 
Place the heat section into low fi re operation.
 • 
Compare the low fi re manifold pressure to Table 
3-2.
 • 
To adjust the low fi re manifold pressure remove 
the cap from the low fi re pressure regulator.  Use 
a 3/32 inch Allen wrench to make the manifold 
pressure adjustment.  To increase the manifold 
pressure, turn the screw clockwise; to decrease 
the manifold pressure, turn the screw counter-
clockwise.  Place your fi nger over the adjustment 
opening while verifying the manifold pressure.
 • 
Turn the heat off.
 • 
Turn the gas off.
 • 
Remove the brass tubing adapter and replace the 
plug in the outlet pressure tap.
TABLE 3-3 – GAS HEAT PERFORMANCE DATA
UNIT
GAS INPUT CAPACITY
(BTU/HR X 1000)
MAXIMUM OUTPUT CAPACITY
(BTU/HR X 1000)
AIRFLOW
TEMP. RISE
(°F)
MIN.
MAX.
50-61
375
300
7,500
24,000
40
750
600
14,000
24,000
40
1125
900
21,000
24,000
40
FIG. 3-2 – MANIFOLD GAS PRESSURE 
ADJUSTMENT
HIGH FIRE PRESSURE
REGULATOR
LOW FIRE
PRESSURE
REGULATOR
TWO STAGE
PRESSURE
REGULATOR
REGULATOR VENT COVER
INLET
TABLE 3-2 – LOW FIRE / HIGH FIRE PRESSURES
TYPE OF 
GAS
LINE PRESSURE
MANIFOLD PRESSURE
MINIMUM
MAXIMUM
LOW FIRE   
+/- 0.3 “WC
HIGH FIRE  
+/- 0.3 “WC
NATURAL
4.5 “WC
13.5 “WC
1.2 “WC 
3.5 “WC
PROPANE
11.0 “WC
13.5 “WC
4.2 “WC
10.0”WC
LD11760a