45
Table 3 —
ISC Board LEDs Status Code Descriptions
NOTES:
1. Green LED blinking at 1HZ indicates normal operation.
2. Solid red LED indicates an error exists; see above LED configuration.
Ventilation
In the Ventilation/Fan Mode (G), the indoor fan will run at low
speed and the damper will operate at minimum position.
Cooling
In the Cooling Mode, the small and large compressors will be se
-
quenced to maintain the thermostat temperature setpoint. Table 4
shows the cooling operation based on the indicated conditions.
The outdoor fan and VFD controlled indoor fan will operate at
low, medium and high speed. The RPM is factory set by the CFM
and static pressure requirements for the unit installed.
Table 4 —
Cooling Mode Operation
Humidi-MiZer
®
System (Optional)
In the Dehumidification Mode, both compressors will run and In
-
door airflow will be rise to High Speed.
At subcooler reheating mode (reheat-1), during part load condi
-
tions when the room temperature and humidity are above the set
point, the unit initiates the sub-cooling mode of operation; a call
for cooling and dehumidification. RDV (Reheat Discharge Valve)
and TWV (Three Way Valve) close; Indoor and Outdoor airflow
will rise until reaching 100% of Speed.
At hot gas bypass reheating mode (reheat-2), when there is a call
for dehumidification without a call for cooling, a portion of the hot
gas from the compressor bypasses the condenser coil when RDV
opens and hot gas is fed into the liquid line, TWV closes in this
mode and the system provides mainly latent cooling. Indoor air
-
flow will rise until reaching 100% of Speed, Outdoor airflow will
run at High speed as long as outdoor temperature is above 80°F
(26.7°C); when operating in this mode below 80°F (26.7°C) OAT,
the system outdoor fan will operate as shown in Table 5 based on
unit size.
Table 5 — Outdoor Fan Operation Below 80°F
(26.7°C) OAT
Economizer (Optional)
When the economizer is in Free Cooling Mode and a demand for
cooling exists (Y1 on the thermostat), the economizer will modu
-
late the outdoor-air damper to provide a 50°F (10°C) to 55°F
(13°C) mixed-air temperature into the zone and run the indoor-fan
at high speed. As mixed-air temperature fluctuates above 55°F
(13°C) or below 50°F (10°C) dampers will be modulated (open or
close) to bring the mixed-air temperature back within control.
Upon more call for cooling (Y2 on the thermostat), the outdoor-air
damper will maintain its current position, compressor C1 will run
and the outdoor-fan will run at low speed. If there is further de
-
mand for cooling, the outdoor-air damper will maintain its current
position, compressor C2 will run and the outdoor-fan will run at
medium speed. The VFD controlled indoor-fan will operate at
high speed regardless of the cooling demand.
If the increase in cooling capacity causes the mixed-air tempera
-
ture to drop below 45°F (7°C), the outdoor-air damper will return
to the minimum position. If the mixed-air temperature continues
to fall, the outdoor-air damper will close. Control returns to nor
-
mal once the mixed-air temperature rises above 48°F (9°C). The
power exhaust fans will be energized and de-energized, if in
-
stalled, as the outdoor-air damper opens and closes.
If field-installed accessory CO
2
sensors are connected to the Econ
-
omizer, a demand controlled ventilation strategy will begin to op
-
erate. As the CO
2
level in the zone increases above the CO
2
set-
point, the minimum position of the damper will be increased pro
-
portionally. As the CO
2
level decreases because of the increase of
fresh air, the outdoor-air damper will be proportionally closed. For
economizer operation, there must be a thermostat call for the fan
(G). If the unit is occupied and the fan is on, the damper will oper
-
ate at minimum position. Otherwise, the damper will be closed.
ERROR #
ERROR NAME
LED INDICATION
LED01
LED02
LED03
LED04
LED05
1
Check Smoke Detector/PMR/AUX
RED
Blinking Green
LED (Note 1)
2
Check HPS/LPS/COFS
RED
RED
3
Call for Y3 with no call for Y1. Check Y1 wiring.
RED
4
Call for Y3 with no call for Y1/Y2. Check Y1 wiring.
RED
RED
5
Call for Y2 with no call for Y1. Check Y1 wiring.
RED
RED
6
Call for W2 with no call for W1. Check W1 wiring.
RED
7
Call for heat (W1/W2) and cooling (Y1/Y2/Y3).
Check thermostat wiring.
RED
RED
RED
RED
8
Call for heat (W1/W2) with no G. Check G wiring.
RED
RED
RED
9
Call for cooling (Y1/Y2/Y3) with no G. Check G
wiring.
RED
RED
RED
10
Call for heat (W1/W2) and cooling (Y1/Y2/Y3) with
no G. Check thermostat and G wiring.
RED
RED
RED
11
Check ISC Board and the thermostat wiring
RED
RED
RED
12
Check ISC Board and the thermostat wiring
RED
13
Check ISC Board and the thermostat wiring
RED
RED
14
Check ISC Board and the thermostat wiring
RED
15
Check ISC Board and the thermostat wiring
RED
RED
INPUT
OUTPUT
Thermostat
Compressor
Indoor Fan
Speed
Outdoor
Fan Speed
C1
C2
First Stage
Cooling (Y1)
On
Off
Low
Low
(700 RPM)
Second Stage
Cooling (Y2)
Off
On
Medium
Medium
(800 RPM)
Third Stage
Cooling (Y2)
On
On
High
High
(1000 RPM)
50LC SIZE
RPM
NUMBER OF
FANS ON
NUMBER OF
FANS OFF
14
250
3
0
17
250
4
0
20
160
4
0
24
250
6
0
26
250
6
0
Summary of Contents for WeatherExpert 50LC14
Page 4: ...4 Fig 2 50LC Vertical Airflow Size 14...
Page 5: ...5 Fig 3 50LC Horizontal Airflow Size 14...
Page 6: ...6 Fig 4 50LC Back View and Condensate Drain Location Size 14...
Page 7: ...7 Fig 5 50LC Corner Weights and Clearances Size 14...
Page 8: ...8 Fig 6 50LC Bottom View Size 14...
Page 9: ...9 Fig 7 50LC Vertical Airflow Sizes 17 20...
Page 10: ...10 Fig 8 50LC Horizontal Airflow Sizes 17 20...
Page 11: ...11 Fig 9 50LC Back View and Condensate Drain Location Sizes 17 20...
Page 12: ...12 Fig 10 50LC Corner Weights and Clearances Sizes 17 20...
Page 13: ...13 Fig 11 50LC Bottom View Sizes 17 20...
Page 14: ...14 Fig 12 50LC Vertical Airflow Sizes 24 26...
Page 15: ...15 Fig 13 50LC Horizontal Airflow Sizes 24 26...
Page 16: ...16 Fig 14 50LC Back View and Condensate Drain Location Sizes 24 26...
Page 17: ...17 Fig 15 50LC Corner Weights and Clearances Sizes 24 26...
Page 18: ...18 Fig 16 50LC Bottom View Sizes 24 26...
Page 21: ...21 Fig 19 Roof Curb Details 14 Size Unit...
Page 22: ...22 Fig 20 Roof Curb Details 17 and 20 Size Units...
Page 23: ...23 Fig 21 Roof Curb Details 24 and 26 Size Units...
Page 30: ...30 Fig 42 50LC 14 26 Electro Mechanical Control Wiring Diagram...
Page 31: ...31 Fig 43 50LC 14 26 RTU Open Control Wiring Diagram...
Page 32: ...32 Fig 44 50LC 14 26 SystemVu Control Wiring Diagram...
Page 35: ...35 Fig 47 Typical Power Wiring Diagram SystemVu Controls 50LC Unit 208 230V Shown...
Page 36: ...36 Fig 48 Typical Power Wiring Diagram SystemVu Controls 50LC Unit 460V 575V Shown...
Page 80: ......
Page 81: ......