User`s manual
Table 7--Air Delivery {Cfm) at indicated Temperature Rise and Rated Heating input
HEATING
INPUT
(BTUH) 20 25 30
40,000 1500 1200 1000
60,000 2250 1800 1500
90,000 -- -- 2250
115,000 -- -- --
130,000 -- -- --
35
857
1286
1929
2464
2786
TEMPERATURE R_SB °F
40 45 50
750 667 600
1125 1000 900
1688 1500 1350
2156 1917 1725
2438 2167 1950
55
545
818
1227
1568
1773
6O
5OO
75O
1125
1438
1625
65
692
1038
1327
1500
NOTE: Dashed areas do not fall within the approved temperature rise range of the unit.
7O
964
1232
AL XILIARY LIMIT SWITCH (ROLLOL T)
The function of the switch is to close the main gas valve in d-ie
event of flame rollout The switch is located above the main
burners. When the temperature at the auxilia_" switch reaches the
maximum allowable temperature, the R contlol circuit tlips,
closing the gas valve and stopping gas flow to the burners. The
indoor (evaporator) fin motor (IFM) and induced draft motor
continue to run until switch is reset. The IGC LED will display
FAULT (ODE 7.
Step a--START-UP COOUNG AND MAKE ADJUST-
MENTS
Complete the required procedures given in the Pro-Start-Up
section before starting the unit
Do not jumper any safety devices when operating the unit.
Do riot operate the compressor when the outdoor temperature
is below 40cT (unless accessory tow=ambient kit is installed).
Do riot rapid-cycle the compressor. Allow 5 minutes between
"on" cycles to prevent compressor damage.
(HE(KING (OOLING (ONTROL OPERATION
Start and check the unit for proper cooling controi operation as
follows:
1. Place room thermostat SYSTEM switch in OFF position
Observe that blower motor starts when FAN switch is placed
in ON position and shuts down when FAN switch is placed in
AUTO. position
2. Place SYSTEM switch in (COL position and FAN switch in
AUTO. position. Set cooling control below room temperature
Observe that compressor, condenser fm_, and evaporator
blower motors start. Observe that cooling cycle shuts down
when control setting is satisfied. The evaporator fhn will
continue to rnn for 30 sec.
3. When using an auto=changeover room thermostat, place both
SYSTEM and FAN switches in AUTO. positions. Observe
that unit operates in Heating mode when temperature control
is set to "call for heating" (above room temperature) arid
operates in (ooling mode when temperature control is set to
"call fbr cooling" (below room temperature)
IMPORTANT: Three-phase, scroll compressor units
(48GS048 arid 48GX030-060) are direction-oriented.
These units must be checked to ensure proper compressor
3-phase power lead orientation If not corrected within 5
minutes, the internal protector shuts off the compressor.
The 3-phase power leads to dte unit must be reversed to
cot_'ect rotation. When taming backwards, scroll compres-
sors emit elevated noise levels, and the difference between
compressor suction and discharge pressures may be &a-
matically lower than normal.
CHE(KING AND ADJUSTING REFRIGERANT (HARGE
The refrigerant system is fidly charged with R-22 refi'igerant,
tested, and fitctow-sealed,
NOTE: A({iustment of d'le ref?ige*ant charge is not required
unless the unit is suspected of not having the proper R-22 charge.
A superheat charging chart is attached to the outside of the service
access panel. The chart includes the required suction line tempera-
rare at given suction line pressures and outdoor ambient tempera-
tures
An accurate superheat, thermocouple- or d-iermistor-type ther-
mometer, a sling psychrometer, and a gauge manifold are required
when using the superheat charging method for evaluating the unit
charge. Do nut u,se7nerc_z_?' or .small diaT-O_e t,s_ermomete_'s
/_ecaz_se they are l_ot adeqzeate jot thi.s 07)e o/" mea.s_zrement.
N
When evaluating d_e refi'igerant charge, an indicated adjust°
ment to d_e specified factory charge must always be ve_-
minimal. If a substantial adjustment is indicated, an abnot_nai
condition exists somewhere in the cooling system, such as
insufi[icient airflow across either coil or both coils.
Proceed as follows:
1, Remove caps fiom tow- and high-pressure smwice fittings,
2 [sing hoses with valve core depressors, attach tow- and
high-pressure gauge hoses to low- and high-pressure service
fittings, respectively,
3 Start unit in Cooling mode and let unit run until system
pressures stabilize,
4 Measm'e and record the following:
a Outdoor ambient-air temperature (C>Fdb),
b Evaporator inlet-air tempe*ante (°F wb),
c Suction-tube temperature (°F) at tow-side service fitting
d Suction (low-side) pressure (psig),
5 Lsing "Cooling Charging Charts," compare outdoor-air ten>
perature (°F db) with the suction line pressure (psig) to
determine desired system operating suction line temperature
(See Fig, 18 30),
2i