Daikin LX10F11B Service Manual Download

Page: 16 / 130

1-10

1.3.8 Printed Circuit Board

●

CPU Board

（

EC1

）

Controller described in this manual as CPU board.
CPU board equips micro-computer and controls
unit with operation software installed.
All information required for the control is input to
the CPU board.

①

Sensor information (temperature, humidity,

pressure) and power information (voltage, phase
sequence, current) are input.

②

Configuration items (factory set) in accordance

with requirement for individual user's order are
input.

③

For example Unit ON/OFF, SP change, etc are

inputted by key operation.

In responding to these inputs, CPU board outputs
commands to each part to operate unit with
accuracy.

①

to modulation valves, solenoid valves and

magnetic contactors

②

to inverter board

③

to LCD display

Operation data is stored for 2 years

（

Logging

interval 60 minutes). The data can be downloaded
using a PC which has the DCCS software installed
or with a USB memory.

When power OFF, some of setting work and data
indication can be available by wake-up battery
power (Rechargeable battery). Data download and
software upload are also possible. (Refer battery
mode in paragraph 2.3)

Use Daikin spare parts for CPU board replacement.
After replacement, configuration items are
transmitted from operation board. Set controller
time in accordance with setting request displayed

on LCD. Install the latest operation software down-
loaded from web site.

●

I/O Board

（

EC2

）

I/O board converts AC24V power from control
transformer Tr1 to DC13V/DC5V and supply it to
CPU board.
I/O board energizes magnetic contactors for fan
motor EFM, CFM and phase correction contactor
PCC1 or 2 by receiving order from CPU board.
At the same time, LED lamps wired in parallel
with them are energized and lighted ON. That is
convenience with service work.

●

Operation Board

（

EC3

）

Operation board receives input from keyboard and
transmits it to LCD board and CPU board. On the
other hand it transmits signals from CPU board to
LCD board.
If communication between operation board and
CPU board is failed, operation board judges to
display "Communication Interrupted" on LCD and
alarm E903 is shown on trip report.
Configuration items factory set to CPU board have
been copied to operation board. When CPU board is
replaced, these items are transmitted to CPU board.

●

Inverter Board

（

EC8

）

Inverter board changes frequency of power source
and controls compressor speed. Inverter board
receives command of rotation speed value from
CPU board. The operating condition during inverter
control (compressor overload, power supply
condition and actual frequency etc.) are transmitted
to CPU board. The judgment for operation
continuing and stopping is conducted by CPU board.
Output from inverter is made of frequent switching
control by power module and results to creating
high temperature. Radiator fin constructed outside
inverter box.

CFM

EFM

PT/CT
EC7

Operation board

EC3

Inverter box

Control box

Compressor

AC24V

3 phase AC

380-415V/50Hz
440-460V/60Hz

Inverter board