Maintenance - Lennox XC21 Series Unit Information

FAN MOTOR SURGE PROTECTION (−05 build only)
Surge Protector (Metal Oxide Varistor − MOV) − A part
designed to protect electrical devices from voltage spikes
that are 3 to 4 times the normal circuit voltage (see figure 27
for illustration of component).
An MOV works as follows: It is essentially a batch of
metallic−oxide grains separated by insulating layers.
Repeated voltage surges break down the insulating layers,
lowering the overall resistance and eventually causing the
device to draw too much current and trip whatever
over−current protection is inherent in the system)
MOV Check: They are supposed to be located beyond the
line fuse (though possibly not always). In this case, where
the line fuse blows or circuit breaker trips but there is no
visible damage to the MOV(s), the simplest test may be to
just temporarily remove the MOV(s) and see if the problem
goes away.
See figure 1 for location of the Surge Protections device in
the unit control box area.
Figure 27. Fan Motor Surge Protection Device
(XC21−XXX−230−05 Only)

Maintenance

OUTDOOR UNIT MAINTENANCE
Outdoor Unit
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each cooling
season, the system should be checked as follows:
1. Outdoor unit fan motor is pre−lubricated and sealed. No
further lubrication is needed.
2. Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.
3. Check all wiring for loose connections.
4. Check for correct voltage at unit (unit operating).
5. Check amperage draw on outdoor fan motor.
Motor Nameplate:_________ Actual:__________.
6. Inspect drain holes in coil compartment base and clean
if necessary.
NOTE - If insufficient cooling occurs, the unit should be
gauged and refrigerant charge should be checked.
Clean and inspect outdoor coil (may be flushed with a water
hose). Ensure power is off before cleaning.
NOTE It may be necessary to flush the outdoor coil more
frequently if it is exposed to substances which are corrosive
or which block airflow across the coil (e.g., pet urine,
cottonwood seeds, fertilizers, fluids that may contain high
levels of corrosive chemicals such as salts)
Sea Coast Moist air in ocean locations can carry salt,
which is corrosive to most metal. Units that are located near
the ocean require frequent inspections and maintenance.
These inspections will determine the necessary need to
wash the unit including the outdoor coil. Consult your
installing contractor for proper intervals/procedures for
your geographic area or service contract.
INDOOR UNIT MAINTENANCE
1. Clean or change filters.
2. Lennox blower
permanently sealed. No more lubrication is needed.
3. Adjust blower speed for cooling. Measure the pressure
drop over the coil to determine the correct blower CFM.
Refer to the unit information service manual for pressure
drop tables and procedure.
4. Belt Drive Blowers − Check belt for wear and proper
tension.
5. Check all wiring for loose connections.
6. Check for correct voltage at unit. (blower operating)
7. Check amperage draw on blower motor.
Motor Nameplate:_________ Actual:__________.
1. Clean coil if necessary.
2. Check connecting lines, joints and coil for evidence of
oil leaks.
3. Check condensate line and clean if necessary.
This product and/or the indoor unit it is matched with may
contain fiberglass wool.
Disturbing the
maintenance, or repair will expose you to fiberglass wool
dust. Breathing this may cause lung cancer. (Fiberglass
wool is known to the State of California to cause cancer.)
Fiberglass wool may also cause respiratory, skin, and
eye irritation.
To reduce exposure to this substance or for further
information, consult material safety data sheets available
from address shown below, or contact your supervisor.
Lennox Industries Inc.
P.O. Box 799900
Dallas, TX 75379−9900
Page 49
Outdoor Coil
Indoor Unit
motors are prelubricated
Indoor Coil
WARNING
insulation during
and
installation,
XC21