ECR RetroAire R90C Installation, operation & maintenance manual - page 23
• Check fan motors and blower assemblies. Some units
may require drop of light oil to motors and/or bearing
assemblies (
look for oil cups
). Verify set-screws and
motor mounting hardware are secure.
• Brush and/or vacuum centrifugal fan blades and blower
cage assemblies.
• Inspect both indoor and outdoor coils. Use fin comb
to straighten any damaged fins. Coils must be clean
for proper operation.
NOTICE
Do not use solvent-based cleaner to clean coils,
some solvents will produce noxious odor when unit is
operating.
• Look for oil leaks or stains on or around all braze
joints and refrigerant lines. Presence of oil indicates
potentially serious problem
(such as a refrigerant leak)
.
• Inspect and clean drain pan and drain line(s). Use of
anti-fungicide tablet to keep condensate system free
from bacterial contaminants is recommended.
• Verify unit pitch. Building and equipment may settle,
causing shift in direction of condensate flow. Unit
should pitch minimum of 5°
(at least
½”
)
to outside
allowing for proper drainage.
• Check weep holes along rear flange of base pan to
ensure free of debris.
• Check seal around unit is not broken or damaged.
NOTICE
Air leaks make conditioned area uncomfortable
drafty or produce noise. Visually inspect foam gasket
between wall and unit, taking note of separation
between air inlet for condenser and condenser coil
discharge. These areas must be sealed off from
each other. If you experience poor cooling operation
or erratic operation, check for air recirculation at
condenser coil.
• Replace access panels and reconnect electrical power.
• Test unit operation.
Troubleshooting Sensors
1.
See Figure 13 for location of sensor connections to
control board.
2.
If temperature response of indoor or outdoor sensor is
not correct, disconnect sensor from control board and
check sensor resistance. Replace sensor if resistance is
not close to values in Table 4.
Table 4 Sensor Resistance Values
Resistance, K ohms
77 (25°C)
10.0 K
50 (10°C)
19.9 K
35 (1.6°C)
30.0 K
30 (-1.1°C)
34.4 K
Figure 13
Sensor Connections On Control
Board
Indoor Sensor Connections
Outdoor Sensor Connections
Heat Pump Units —
Temporary Emergency
Heating Mode
Heat pump failure, control board can be forced into electric
heat mode.
This is temporary solution until heat
pump system is repaired.
• Locate circuit board in control section of unit.
• Locate terminals where outdoor sensor connects to
circuit board.
• Use small needle nose type pliers, disconnect one side
of sensor from circuit board. 2-stage thermostat will
provide Emergency heat.
• Circuit board sees this as outdoor coil freeze condition
energizing electric resistance heater on call for heat.
• See "Manual Reset Limit Switch". See Figure 12,
page 22 to reset limit switch if needed.
MAINTENANCE
P/N 240010330, Rev. A [10/15/2013]
23
Made in USA