Scheduled Maintenance; Servicing - Daikin M Series Service And Troubleshooting

SCHEDULED MAINTENANCE

Package gas units require regularly scheduled
maintenance to preserve high performance standards,
prolong the service life of the equipment, and lessen the
chances of costly failure.
In many instances the owner may be able to perform some
of the maintenance; however, the advantage of a service
contract, which places all maintenance in the hands of a
trained serviceman, should be pointed out to the owner.
HIGH VOLTAGE
DISCONNECT ALL POWER BEFORE SERVICING
OR INSTALLING THIS UNIT. MULTIPLE POWER
SOURCES MAY BE PRESENT. FAILURE TO DO SO
MAY CAUSE PROPERTY DAMAGE, PERSONAL
INJURY OR DEATH.
Once A Month
1. Inspect the return filters of the evaporator unit and
clean or change if necessary.
NOTE: Depending on operation conditions, it may be
necessary to clean or replace the filters more often.
If permanent type filters are used, they should be
washed with warm water and dried.
2. When operating on the cooling cycle, inspect the
condensate line piping from the evaporator coil.
Make sure the piping is clear for proper condensate
flow.
Once A Year
Qualified Service Personnel Only
1. Clean the indoor and outdoor coils.
2. Clean the cabinet inside and out .
3. Motors are permanently lubricated and do not require
oiling. TO AVOID PREMATURE MOTOR FAILURE,
DO NOT OIL.
4. Manually rotate the outdoor fan and indoor blower to
be sure they run freely.
5. Inspect the control panel wiring, compressor
connections, and all other component wiring to be
sure all connections are tight. Inspect wire insulation
to be certain that it is good.
6. Check the contacts of the compressor contactor. If
they are burned or pitted, replace the contactor.
7. Using a halide or electronic leak detector, check all
piping and etc. for refrigerant leaks.
8. Check the combustion chamber (Heat Exchanger)
for soot, scale, etc. Inspect all burners for lint and
proper positioning.
9. Start the system, using the proper instrumentation
check gas inlet and manifold pressures, burner flame
WARNING
and microamp signal. Adjust if necessary.
10. Start the system and run a Heating Performance
Test. If the results of the test are not satisfactory, see
the "Service Problem Analysis" Guide for the possible
cause.
Test Equipment
Proper test equipment for accurate diagnosis is as
essential as regular hand tools.
The following is a must for every service technician and
service shop:
1. Thermocouple type temperature meter - measure dry
bulb temperature.
2. Sling psychrometer- measure relative humidity and
wet bulb temperature.
3. Volt-Ohm Meter - testing continuity, capacitors, motor
windings and voltage.
4. Accurate Leak Detector - testing for refrigerant leaks.
5. High Vacuum Pump - evacuation.
6. Electric Vacuum Gauge, Manifold Gauges and
high vacuum hoses - to measure and obtain proper
vacuum.
7. Accurate Charging Cylinder or Electronic Scale -
measure proper refrigerant charge.
8. Inclined Manometer - measure static pressure and
pressure drop across coils.
Other recording type instruments can be essential in
solving abnormal problems, however, in many instances
they may be rented from local sources.
Proper equipment promotes faster, more efficient service,
and accurate repairs with less call backs.
Heating Performance Test
Before attempting to diagnose an operating fault code, run
a Heating Performance Test to determine if the heating
system is performing within 5% of the BTU input found
on the rating plate of the unit being tested. To conduct a
heating performance test, the BTU input to the unit must
be calculated (see Clocking a Gas Meter). Before clocking
a gas meter, contact your local utility to provide the caloric
value (BTU content) of the natural gas in the area.
It is also important to confirm the airflow (CFM) is within
the temperature rise range (see Airflow Data in spec sheet)
and external static pressure range (approximately 0.5"
water column). How-to instructions can be found in the
service manual under Checking External Static Pressure
and Checking Temperature Rise.
Clocking a Gas Meter
1. Turn off all gas appliances in the home.
2. Turn on the furnace. Ensure the furnace is operating
at a 100% firing rate on 2 stage and modulating
furnace product.
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