Page 33
10-Spark Electrodes
An electrode assembly is used for ignition spark. Two iden-
tical electrodes are used (one for each gas heat section). 
The electrode is mounted through holes on the left-most 
end of the burner support. The electrode tip protrudes into 
assembly is fastened to burner supports and can be re-
moved for service without removing any part of the burn-
ers. During ignition, spark travels through the spark elec-
from burner to burner until all are lit. The spark electrode is 
connected to the ignition control by a 8 mm silicone-insu-
mm)female quick connect on the electrode end and fe-
male spark plug-type terminal on the ignition control end.
NOTE- IN ORDER TO MAXIMIZE SPARK ENERGY TO 
ELECTRODE, HIGH VOLTAGE WIRE SHOULD TOUCH 
UNIT CABINET AS LITTLE AS POSSIBLE.
GROUND
ELECTRODE
GROUND
ELECTRODE
(3.2 mm ± .4 mm)
FIGURE 23 
11-Flame Sensors
-
er support. The sensor is mounted through a hole in the 
-
lope of the right most burner. The sensor assembly is fas-
tened to burner supports and can be removed for service 
without removing any part of the burners.
       -
       
passed along the ground electrode (located on the spark 
        -
trode. The ignition control allows the gas valve to stay 
       
FIGURE 24 
II-PLACEMENT AND INSTALLATION
Make sure the unit is installed in accordance with the in-
stallation instructions and all applicable codes. See ac-
cessories section for conditions requiring use of the op-
tional roof mounting frame.
III-CHARGING
A-Refrigerant Charge and Check - Fin/Tube Coil
NOTE- Do not exceed nameplate charge under any con-
dition.
This unit is factory charged and should require no further 
adjustment. If the system requires additional refrigerant, 
reclaim the charge, evacuate the system and add required 
nameplate charge.
NOTE - System charging is not recommended below 60°F 
(15°C).  In  temperatures  below  60°F  (15°C),  the  charge 
must be weighed into the system. If weighing facilities are 
not  available,  or  to  check  the  charge,  use  the  following 
procedure:
IMPORTANT - Charge unit in normal cooling mode.
1 -   Attach gauge manifolds to discharge and suction 
lines. With the economizer disabled, operate 
the unit in cooling mode at high speed using the 
following mobile service app (the QR code is in the 
unit control area) menu path:
SERVICE>TEST>COOL>COOL 4
2 -   Use a thermometer to accurately measure the 
outdoor ambient temperature.
3 -  
18 to determine normal operating pressures. 
Pressures are listed for sea level applications at 
4 -   Compare the normal operating pressures to 
the pressures obtained from the gauges. Minor 
variations in these pressures may be expected due 
could mean that the system is not properly charged 
or that a problem exists with some component in 
the system. Correct any system problems before 
proceeding.
5 -   If discharge pressure is high, remove refrigerant 
from the system. If discharge pressure is low, add 
refrigerant to the system.
•  Add or remove charge in increments.
•  Allow the system to stabilize each time refrigerant is 
added or removed.
  Use the following approach method along with the 
TABLE 9 
Outdoor 
Coil 
Entering 
Air 
Temp
Circuit 1 Circuit 2 Circuit 3
Dis. 
+10 
psig
Suc. 
+5 
psig
Dis. 
+10 
psig
Suc. 
+5 
psig
Dis. 
+10 
psig
Suc. 
+5 
psig
 228 127  131 258 140
  130  134  148
  133 337  340 153
 352 135 383  387 
 403  432 142 433 
 457 142 485 145