Amana A/GPUM3, Manual

Page: 18 / 32

18
SPEED
TAP DEFINITION
LEAD
COLOR
SPEED
TAP DEFINITION
LEAD
COLOR
SPEED
TAP DEFINITION
LEAD
COLOR
T1 Fan Only Green T2 Heat White T3 Low Speed Purple
T4 High Speed Yellow
T5
High Speed
Hi-Static
FAN ONLY HEATING COOLING
Two Stage Models
NOTE: Heating airflow must be adjusted to provide
the temperature rise shown on rating plate.
Limit Check
Check limit control operation after 15 minutes of operation
by blocking the return air grille(s).
1. After several minutes the main burners must go OFF.
Blower will continue to run.
2. Remove air restrictions and main burners will relight
after a cool down period of a few minutes.
Adjust the thermostat setting below room temperature.
1. Main burners must go OFF.
2. Circulating Air Blower will continue to run for 90, 120,
150 or 180 seconds, depending on the setting.
NOTE: If necessary, adjust fan OFF delay settings
to obtain satisfactory comfort level.
WARNING
This unit must be used as a “construction heater” during the
finishing phases of construction on a new structure. This
type of use may result in premature failure of the unit die
to extremely low return air temperatures and exposure to
corrosive or very dirty atmosphere.
Unit Shutdown
1. Set the thermostat to lowest setting.
2. Turn off the electrical power supply to the unit.
3. Remove the heat exchanger door on the side of the
unit by removing screws.
4. Move the gas control valve switch to the OFF position.
Do not force.
5. Close manual gas shutoff valve external to the unit.
6. Replace the heat exchanger door on the unit.
7. If cooling and/or air circulation will be desired, turn
ON the electrical power.
Cooling Startup
NOTE: The outdoor temperature must be 60°F or
higher before making adjustments to charge.
NOTE: Check all manual reset limit controls in
heating circuit if cooling mode does not operate.
Compressor Protection Devices
The compressor includes components which are designed
to protect the compressor against abnormal operating
conditions.
WARNING
To prevent personal injury or death, always disconnect
electrical power before inspecting or servicing the
unit. NOTE: All compressor protection devices reset
automatically, energizing the contactor and outdoor fan.
WARNING
Do not bypass safety devices.
Refrigerant Charge Check
After completing airflow measurements and adjustments
the unit’s refrigerant charge must be checked. The unit
comes factory charged, but this charge is based on 325
CFM per ton and minimum ESP per AHRI test conditions
(generally between .15-.28 ESP). When air quantity or
ESP is different than above, the refrigerant charge must be
adjusted to the proper amount. All package units with fixed
orifice devices are charged using the super heat method at
the compressor suction line.
After superheat is adjusted it is recommended to check unit
sub-cooling at the condenser coil liquid line out. For charge
adjustments, see superheat and sub-cooling charts show
for each model.
Checking Subcooling
NOTE: Units with a TXV should be charged to
Subcooling only.
SUBCOOLING FORMULA = SATURATED LIQUID LINE
TEMPERATURE - LIQUID LINE TEMPERATURE
EXAMPLE:
a. Liquid Line Pressure = 417 PSI
b. Corresponding Temp. = 120°F
c. Thermometer on Liquid line = 109°F.
To obtain the amount of subcooling, subtract 109°F
from 120°F. The difference is 11° subcooling. See the
specification sheet or technical information manual for the
design subcooling range for your unit.
SUBCOOLING FORMULA = SATURATED LIQUID LINE
TEMPERATURE - LIQUID LINE TEMPERATURE
Checking Superheat
EXAMPLE:
a. Suction Pressure = 143 PSI
b. Corresponding Temp. = 50°F
c. Thermometer on Suction Line = 59°F