Service Manual

SCHEDULED M AINTENANCE
21
The owner should be made aware of the fact, t hat , as with any
mechanical equipment the Package Cooling and Heat Pump units
require regularly scheduled maintenance to preserve high per-
formance st andards, prolong t he service life of the equipment,
and lessen the chances of cost ly failure.
In many inst ances the ow ner 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 service-
man, should be point ed out to the owner.
WARNING
ONCE A M ONTH
1. Inspect the ret urn filters of the evaporat or unit and clean or
change if necessary.
NOTE: Depending on operat ion condit ions, it may be necessary
to clean the filters more oft en. If permanent type filters are used,
they should be washed wit h warm wat er, dried and sprayed w ith
an adhesive according t o manufacturers recommendat ions.
2. When operating on t he cooling cycle, inspect the conden-
sate line piping from the evaporat or coil. M ake sure the pip-
ing is clear for proper condensate flow.
ONCE A YEAR
Qualified Service Personnel Only
1. Clean the indoor and out door coils.
2. Clean the casing of the out door unit inside and out .
3. M otors are permanent ly lubricated and do not require oil-
ing. TO AVOID PREM ATURE M OTOR FAILURE, DO NOT OIL.
4. M anually rot at e t he outdoor fan and indoor blower to be
sure t hey run freely.
5. Inspect the control panel wiring, compressor connections,
and all other component wiring to be sure all connect ions
are t ight. Inspect wire insulation to be cert ain that it is good.
6. Check the contact s of the compressor contactor. If they are
burned or pit t ed, replace the cont actor.
7. Using a halide or elect ronic leak detector, check all piping
and etc. for refrigerant leaks.
8. Check t he combust ion chamber (Heat Exchanger) for soot,
scale, et c. Inspect all burners for lint and proper positioning.
9. St art the syst em, using the proper inst rument at ion check gas
inlet and manifold pressures, burner flame and microamp
signal. Adjust if necessary.
10. Start the syst em and run both a Cooling & Heating Perfor-
mance Test . If the result s of the test are not satisfactory, see
the "Service Problem Analysis" Chart of the possible cause.
TEST EQUIPM ENT
Proper test equipment for accurate diagnosis is as essent ial as
regular hand t ools.
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. Amprobe - measure amperage and voltage.
4. Volt-Ohm M eter - test ing continuity, capacitors, and mot or
windings.
5. Accurate Leak Detect or - test ing for refrigerant leaks.
6. High Vacuum Pump - evacuation.
7. Elect ric Vacuum Gauge, M anifold Gauges and high vacuum
hoses - t o measure and obtain proper vacuum.
8. Accurate Electronic Scale - measure proper refrigerant charge.
9. Inclined M anometer - measure st at ic pressure and pressure
drop across coils.
Other recording type instrument s can be essential in solving ab-
normal problems, however, in many inst ances they may be rent ed
from local sources.
Proper equipment promotes faster, more efficient service, and
accurat e repairs with less call backs.