Bryant 542E - Manual (Page 8)

3. Make certain all field and factory wiring connections
have been completed and are tight.
4. Inspect all supply ducts and grilles to be sure they are
open.
5. Check for correct position of outdoor fan blade in fan
orifice. Blades should clear fan motor by no more than
1/4 inch.
6. Check to be sure air filters are in proper place.
7. Fill condensate drain pan with water to assure proper
drainage.
8. Make certain all tools and miscellaneous loose parts
have been removed.
9. If coil fins have been damaged during shipping and han­
dling, carefully straighten fins with a fin comb.
10. Replace all access panels. Unit is now ready for initial
startup.
VI. REFRIGERANT LEAKS
In rare instances when the factory refrigerant charge has
been lost because of a shipping damage leak, or when a re­
frigerant leak has been found, proceed as follows:
1. Locate leak and ensure that refrigerant system
prressure has been relieved.
2. Repair leak following accepted practices.
3. Add a small charge of R-22 refrigerant to system and
leak-test unit.
4. If additional leaks are not found, evacuate refrigerant
system.
5. Charge unit with R-22 refrigerant to exact amount
shown on unit rating plate, using volumetric charging
cylinder or accurate scale.
NOTE: It is recommended that a filter-drier be installed
whenever the system has been open for repair. If a filter-
drier has been installed, be sure to add enough extra R-22 to
compensate for the internal volume of the filter-drier.
VII. STARTUP AND ADJUSTMENTS
CAUTION: Ho
nm lu'iiperanv .-.afct\ di'\ue.s wln-n oiu-nii
ing the unit. Do not operate the compressor until electric
power has been applied to the heat pump for a minimum of 4
hours to ensure that the off-cycle crankcase heater has sufii-
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cumulated refrigerant.
A. Checking Unit Operation
The heat pump should be started and checked for proper
operation as follows:
1. Set room thermostat SYSTEM switch to OFF position.
Observe that indoor 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 COOL position and FAN
switch in AUTO position. Set thermostat temperature
setting to “call” for cooling. Compressor, outdoor fan,
and indoor blower motors should start. Observe that
unit shuts down when thermostat temperature setting
is satisfied. Wait 5 minutes for pressues to equalize.
3. Place SYSTEM switch in HEAT position and leave FAN
switch in AUTO position. Increase room thermostat
temperature setting gradually unitl thermostat “calls”
for heat. Compressor, outdoor fan, and indoor blower mo­
tor should start. If supplemental electric heater is being
used in the system, increase room thermostat tempera­
ture setting an additional 6 degrees. The supplemental
electric heater should energize. Set thermostat setting
below room temperature and observe that heater
deenergizes and that heat pump shuts down.
4. If supplemental electric heater is being used in the sys­
tem, leave FAN switch in AUTO position, SYSTEM
switch in HEAT position, and move emergency heat
switch from NORM, position to EM. HT. position. Set
room thermostat temperature setting above room tem­
perature. Observe that all supplemental electric heat is
energized, that indoor blower motor starts, and that
emergency heat indicator bulb lights. When thermostat
temperature setting is satisfied, observe that heater
deenergizes and that blower motor stops; however,
indicator light should remain on as long as emergency
heat switch is in EM. HT. position.
5. If autochangeover thermostat P/N 34427DP115 is
being used, place both SYSTEM and FAN switches in
AUTO position. Observe that heat pump operates in
heating mode when thermostat temperature selector is
set above room temperature, and operates in cooling
mode when selector is set below room temperature.
B. Checking and Adjusting Refrigerant Charge
The refrigerant system has been fully charged with R-22 re­
frigerant, tested, and factory-sealed. The factory charge is
the correct charge for optimum performance for most in­
stallations; however, this charge may require a slight
adjustment for some installations to assure full rated per­
formance.
An operating pressure/temperature tag (also see Tables IV
and V) is fastened inside the unit compressor compartment.
This tag is provided so that the refrigerant charge can be
evaluated by checking operating pressures and tempera­
tures. This method of checking is sufficiently accurate to
determine the adequacy of the refrigerant charge in the sys­
tem when the conditions and system components are nor­
mal; however, it does not solve or fix system abnormalities.
The evaluation indicates whether the refrigerant charge
needs a slight increase or decrease to establish the correct
operating pressures for the system at the time of checking.
The level of refrigerant operating charge determines how
efficiently and economically the unit will operate. An over­
charged or undercharged unit will lead to insufficient heat­
ing and cooling mode capacity, high operating costs, and the
possibility of premature compressor failure.
When checking the refrigerant using the temperature/pres-
sure evaluation method, adhere to the following criteria:
1. Check refrigerant charge in cooling mode when outdoor
temperature is above 65°F.
2. Check refrigerant charge in heating mode when outdoor
temperature is below 65°F.
3. For best results, do not operate unit continuously for
more than 10 minutes if for any reason charge must be
checked in opposite mode above or below 65°F.
Proceed as follows to evaluate the system performance and
refrigerant charge level:
1. Remove caps from low- and high-pressure service fit­
tings. See Figure 12.
2. Attach low- and high-side pressure gauge hoses to low-
and high-pressure service fittings, respectively. Hoses
must have valve core depressors. Gauges should be cali­
brated for accuracy.
3. Set room thermostat below room temperature to start
cooling operation or above room temperature to start
heating operation, depending on outdoor temperature.
Allow unit to operate until conditions stabilize and pres­
sures level out.
4. Determine and record these conditions:
a. Low- and high-side pressure.
b. Dry-bulb temperature of inlet air at outdoor coil.
c. Temperature of inlet air at return-air grille—wet
bulb if operating in cooling mode or dry bulb if
operating in heating mode.
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