Unit Start-Up; Troubleshooting - Lennox MHA Series Installation Instructions Manual

BLUE
RED
V
U
COMPRESSOR
Y/G

Unit Start-Up

IMPORTANT
Units should be energized 24 hours before unit start­up
to prevent compressor damage as a result of slugging.
1. Inspect all factory- and field-installed wiring for loose
connections.
2. Verify that the manifold gauge set is connected.
3. Add additional refrigerant charge if required before
opening valves and while system is still under a
vacuum.
4. Open the liquid and suction line service valves to
release the refrigerant charge contained in outdoor
unit into the system.
5. Replace the stem caps and tighten to the value listed
in "Table 3. Torque Requirements" on page 7.
6. Check voltage supply at the outdoor unit terminal strip.
The voltage must be within the range listed on the
unit's nameplate. If not, do not start the equipment
until you have consulted with the power company and
the voltage condition has been corrected.
7. Refer to the included user guide to operate the system
using the provided remote control.
8. Visually check for binding of both indoor and outdoor
fans.
Y/G
OUTDOOR CONTROL
U
V
W
BLACK
W
CN 17 CN 414
DC- FAN
Y/G
TP/
T5
Figure 39. 24K - 208/230VAC Outdoor Unit Wiring Diagram
Y/G
BLUE
S
Y/G
CN 6 CN 7 CN 8 CN 2
CN 3
3

Troubleshooting

Table 10. Indoor Unit Error Codes
Display Error Information
E0 Indoor unit EEPROM parameter error
E1 Indoor / outdoor units communication error
E2 Zero-crossing signal detection error
The indoor fan speed is operating outside of the normal
E3
range
Indoor room temperature sensor T1 is in open circuit or
E4
has short circuited
Evaporator coil temperature sensor T2 is in open circuit or
E5
has short circuited
EC Refrigerant leak detected
F0 Overload current protection
Outdoor ambient temperature sensor T4 open circuit or
F1
short circuit
Condenser coil temperature sensor T3 is in open circuit or
F2
has short circuited
Compressor discharge temperature sensor TP open circuit
F3
or short circuit
F4 Outdoor unit EEPROM parameter error
The outdoor fan speed is operating outside of the normal
F5
range
p0 IPM malfunction or IGBT over-strong current protection
p1 Over voltage or over low voltage protection
p2 High temperature protection of IPM module
18
BLACK 3
1 2 3 L1L2
L1 L2
Y/G
4-WAY
CRANKCASE
HEATER
PAN
HEATER