Periodic maintenance -
monthly
Belt tensioning
A Browning
®
belt tension gauge is used in Figure 58
to check the belts for appropriate tension.
Filters
Check the cleanliness of the filters, and replace or
clean as required.
Linkages
Examine the damper and operator linkages to
ensure that each is free and operating smoothly.
Compressors
Oil level check
The oil level can only be tested when the
compressor is running in stabilized conditions
to ensure that there is no liquid refrigerant in
the lower shell of the compressor. When the
compressor is running in stabilized conditions, the
oil level must be between 1/4 and 3/4 in the oil sight
glass, if equipped.
Note:
At shutdown, the oil level can fall to the
bottom limit of the oil sight glass.
For 40 ton to 80 ton high efficiency units ONLY,
an optical sensor is provided over the sight glass,
in which the unit controller monitors the correct
oil level. If too low, the unit controller adjusts
the compressor speed to try to recover oil to the
compressor. If that fails, then the unit controller
shuts off the compressor
Oil analysis
Use York Type T POE oil (clear) for units charged
with R-410A refrigerant. The type of refrigerant and
amount per system is listed on the unit nameplate.
A change in the oil color or odor may be an
indication of contaminates in the refrigeration
system. If this occurs, take an oil sample and
analyze it. If contaminations are present, the system
must be cleaned to prevent compressor failure.
Clean the system by installing oversized suction
and liquid line driers. The driers may have to be
changed several times to fully clean the entire
system depending on the degree of contamination.
CAUTION
When using the factory installed valve package to
perform a pump-down of the refrigerant system, do
not allow the scroll compressor to pump the low side
into a vacuum. Pump-down should be stopped when
suction pressure reaches 10 psig. The remaining
refrigerant must be removed using proper recovery
methods.Allowing a scroll compressor to pump into
a vacuum causes internal arcing of the compressor
motor, which results in compressor motor failure.
Condenser and evaporator coils
Dirt should not be allowed to accumulate on the
condenser coil surfaces. Cleaning may be required
as necessary to keep the coil surfaces clear in order
to maintain proper operation of the unit.
Regular cleaning is an essential part of maintaining
the integrity and heat transfer properties of heat
exchangers. The reduced depth and parallel tube
layout of the coils minimizes the restriction of
cleaning water through the heat exchanger. This
can provide a shorter and more direct path for
cleaning water to carry away dirt and debris in coils
during regular maintenance.
In addition, the simple fin layout makes it possible
to use nylon bristle brushes to sweep debris on the
heat exchanger face without the use of water.
The condenser coil cleaning hatches on both sides
of the condenser frame provide access to clean the
coils. See Figure 60 and Figure 61.
•
DO NOT use coil cleaners or any chemical on
the coils. This can cause severe damage to the
coils.
•
DO NOT use a pressure washer to clean the
coils.
•
DO NOT contact the coil with a hard surface
such as a hose nozzle, metal vacuum nozzle,
or any other tool.
•
DO NOT clean when ambient temperatures
would cause the water to freeze before the
water dries from the coil. This can cause
severage damage to the coils.
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
93
Tempmaster
