Toshiba MMY-MAP1006FT8(J)P-E Service Manual page 81

Item Description of operation, numerical data, and other information
12. A3-IPDU IPDU controls inverter compressors by issuing commands relating to compressor
control 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.
Current control values for various outdoor units are shown below.
2. Heat sink temperature detection control
1) This control function is aimed at protecting IGBT from overheating via a thermistor
(TH sensor) mounted in the compressor drive module (Q201) of A3-IPDU.
2) When TH
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 < 85°C.
4) When TH
5) Compressors are restarted 2 minutes and 30 seconds later, with an 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 fault.
* The TH temperature used in this control function is the highest registered by A3-
IPDU1, A3-IPDU2.
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 a 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.
Current
Zone B
I
1
Zone D
I
2
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.
Outdoor unit HP capacity
20
18
16
14
12
10
8
85°C is detected, the fan operation mode is raised by
105 °C, compressors are shut down.
Zone C
I 1 (A) I 2 (A)
23.7 23.2
21.6 21.1
19.5 19.0
17.5 17.0
15.2 14.7
12.7 12.2
10.5 10.0
− 80 −
Remarks
•
A3-IPDU1 and 2 are each
provided with a TH sensor.
• Connected to A3-IPDU, the
high-pressure SW is
normally closed.