Table of Contents
Advertisement
Quick Links
Service Manual For
Trans/Air EC3.0 Electronic Climate Control System
Specification
Operating Voltage:
Current capacity:
Setpoint range:
Component:
EC3.0 system consist of two major components: driver control switches and relay board. A
communication cable connects the switches to the board.
Switches
EC3.0 control switches: Mode switch (701426), Thermostat (701425).
Relay Board
The layout of an EC3.0 relay board is shown below. It has five relays, one 12 position
terminal block, three 10 amp fuses, two connectors and seven LED indicators. The function
of each component are listed in table below
9~16 VDC
Evaporator: 40 amp
Condenser: 40 amp
Compressor: 10 amp
Tie-in Condenser: 40 amp
Tie-in Compressor: 10 amp
Heat Relay:
10 amp
60ºF ~ 90ºF
ON/OF & MODE SELECT
A/C-DEFOG-HEAT-OFF
DEFOG
HEAT
A/C
FAN SPEED INDICATOR
FAN SPEED SELECT
AUTO-L-M-H-OFF
Figure 1 Control Switches
EC3 Service Manual Jan. 8, 2008
DISPLAY
SET POINT
ADJUST
1
Advertisement
Table of Contents
Summary of Contents for Trans Air EC3.0
- Page 1 Figure 1 Control Switches Relay Board The layout of an EC3.0 relay board is shown below. It has five relays, one 12 position terminal block, three 10 amp fuses, two connectors and seven LED indicators. The function of each component are listed in table below...
-
Page 2: Relay Board Layout
Figure 2 Relay Board Layout Table 1 Relay Configuration RELAY FUNCTION Currant rating COMPR. Compressor clutch relay 10 amp TIE-IN COMPR OEM tie-in compressor clutch relay 10 amp HEAT Heat valve control relay 10 amp TIE-IN COND. Tie-in condenser fan control relay 40 amp COND. -
Page 3: System Operation
EC3.0 system only displays the temperature between 60 ºF and 90 ºF. If the actual temperature is lower than 60 ºF, the display will show “Lo”. If the temperature is above 90ºF, the display will show “Hi”. -
Page 4: Fan Speed Control
Fan Speed Control EC3.0 system has two speed control modes. Auto fan speed control and manual fan speed control. In manual fan speed control, there are three settings High, Medium and Low. In auto fan speed control mode, evaporator blower speed is controlled based on the temperature differential between Tin and Tset. -
Page 5: Service Timer
Beside safety switches, EC3.0 also monitors two other electrical faults: low clutch voltage and blown fuse. The EC3.0 system senses the voltage on terminal 8 (clutch power input terminal). If the voltage on terminal drops below 11.9 vdc, EC3.0 system will turn off condenser output and compressor clutch output and display “Lu”... -
Page 6: Troubleshooting
Slave board configuration In some large systems where the electrical load exceeds the current capability of a single board, a slave board can be used. A typical wiring diagram is 5031xxxx. In a slave system, the switches are connected to the master board and the slave board is connected to the master board through a harness 701442.