EC3 Service Manual Jan. 8, 2008
1
Service Manual For
Trans/Air EC3.0 Electronic Climate Control System
Specification
Operating Voltage:
9~16 VDC
Current capacity:
Evaporator: 40 amp
Condenser: 40 amp
Compressor: 10 amp
Tie-in Condenser: 40 amp
Tie-in Compressor: 10 amp
Heat Relay:
10 amp
Setpoint range:
60ºF ~ 90ºF
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).
ON/OF & MODE SELECT
A/C-DEFOG-HEAT-OFF
FAN SPEED INDICATOR
FAN SPEED SELECT
AUTO-L-M-H-OFF
A/C
DEFOG
HEAT
SET POINT
ADJUST
DISPLAY
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
