1
2
. A3-IPDU
control
IPDU controls inverter compressors by issuing commands relating to compressor
speeds, speed increases/decreases, and current release control values via the
interface P.C. board.
The main control functions of the IPDU P.C. board are described below.
1. Current release control
To prevent inverter input current from exceeding the specified value, output
frequency is controlled with AC input current as detected by T02 mounted on the
control P.C. board.
2. IPM built-in
temperature
(TH)
detection control
1)
This control function is aimed at protecting
IPM
from overheating via a thermistor
(TH sensor) mounted in the compressor drive module (Q201) of A3-IPDU.
2) When TH
about 75~
8
0
°C
*1
is detected, the fan operation mode is raised by
one step,
followed by a series of additional step-ups right up to the highest mode
at a rate of
one step/5 seconds.
3)
After step 2), the normal fan mode is restored when TH falls to <
about 75~
8
0
°C
*1
.
4)
When TH
97
°C, compressors are shut down.
5)
Compressors are restarted 2 minutes and 30 seconds later, with a
failure
count of
1
recorded. If this is repeated four times (
failure
count reaches 4), the
check code
is
confirmed as final. The
check code
[P07] is displayed. (There will be no more
restarts.)
* Possible causes of the confirmed
failure
include a heat buildup in the outdoor unit, fan
abnormality, blockage of the cooling duct, and IPDU P.C. board
trouble
.
* The TH temperature used in this control function is the highest registered by A3-IPDU1,
A3-IPDU2.
•
A3-IPDU1 and
2
are each
provided with a TH sensor.
3.
Overcurrent protection control
1)
When the overcurrent protection circuit on an IPDU P.C. board detects an
abnormal current, the compressor is shut down.
2)
The compressor is restarted 2 minutes and 30 seconds later, with an
failure
count
of 1 recorded. If the compressor successfully operates for at least 10 minutes after
a restart, the
failure
count is cleared.
3)
If the
failure
count reaches 8, the
check code
is confirmed as final.
4.
High pressure SW control
1)
When the high pressure SW of an inverter compressor is activated, the
compressor is shut down with a
failure
count of 1 recorded.
2)
The compressor is restarted 2 minutes 30 seconds later, and, if it successfully
operates for at least 10 minutes, the
failure
count is cleared.
3)
If the
failure
count reaches 4, the
check code
is confirmed as final. The
check
code
“P04”
is
displayed.
• Connected to A3-IPDU, the
high-pressure SW is
normally closed.
Item
Description of operation, numerical data, and other information
Remarks
Zone C
Zone B
Zone D
I
1
I
2
Current
Zone A
Zone A:Compressors are operated normally.
Zone D:The current operating frequency is maintained.
Zone B:Operating frequency is lowered.
Zone C:The lowering of operating frequency is halted
to maintain the current frequency.
Current control values for various outdoor units are shown below.
Outdoor unit HP capacity
I1
(A)
I2
(A)
*1 It changes depending on
the model and temperature
condition.
1
2
1
0
8
1
2.7
1
0
.5
1
0.0
12.2
1
0
.0
9.5
- 46 -
