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7.0 COMPONENTS & CONTROLS
7.7 EcoNet
TM
Variable Speed Outdoor Control (VSODC)
7.7.1 Board Features and
Connections
(-)A20 condensing units are equipped with a Variable
Speed Outdoor Control (VSODC) that interfaces with
the inverter, EcoNet
TM
Control Center, and EcoNet
TM
enabled air-handler or gas furnace using the EcoNet
TM
serial communication protocol. The VSODC provides
a low voltage terminal block for control wiring and
connections for various sensors, controls, outdoor fan
motor and inverter. It also has a dual 7-segment LED
for displaying status and fault codes. Buttons are
provided for navigating the control menu and to initiate
and terminate various test modes. A plug-in memory
card provides model specific information (model data)
necessary for proper unit operation and parameters for
the correct indoor air-flow.
The following is a list of features on the VSODC
and location of each.
1. Thermostat Terminals
2. Communication wire terminals
3. Modbus unitary inverter communication
connection
4. Outdoor PSC Fan relay connections
5. Outdoor ambient thermistor connection
6. Coil sensor (EVAPIN) and suction thermistor
(OST) connections
7. Liquid line (OLT – for future use) and
compressor sump (CPT) connections
8. Outdoor ECM fan PWM output connection
9. Suction pressure transducer (SPT) connection
10. Liquid pressure transducer (LPT) connection
(for future use)
11. Electronic expansion valve connection
(not used)
12. Reversing Valve Connections (not used)
13. 3 Amp fuse
14. Test and SW2 Button
15. Communications LEDs (ET – EcoNet™
communication is transmitting; RT –
EcoNet™communication is receiving)
16. Memory card connection
17. Dual seven segment LED – Displays status,
diagnostic codes, fault recall and compressor
speed
18. Dip Switches (Defrost [DFST] and EXV [EXV]
offset) (not used)
19. Dip Switches (EXV [1600/500] selection)
(not used)
20. EXV Operational Lights (not used)
CAUTION:
UNIT MAY START
SUDDENLY AND WITHOUT WARNING.
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16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
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Components