Toshiba MMU-P0121H Service Manual page 36

Item
11. Crank case This control is executed by the fixed-speed unit only.
heater control
(1) Control contents
12. IPDU (inverter) IPDU controls the inverter compressor by command frequency,
control frequency up/down speed, and current release control value
from the interface P.C. board.
The main controls of IPDU control P.C. board are described
below.
(1) Current release control
(2) Heat sink temp. detection control
NOTE :
When the error has been determined, the heat in outdoor unit or
on outdoor fan error is considered.
(3) Over-current protective control
(4) High pressure SW control
Operation explanation and applied data, etc.
• This control is switch off when TK3 sensor detected 40°C
or higher temperature, and switch on when TK3 sensor
detected 35°C or lower temperature.
• After the compressor status changed from OFF to ON, ON
status continues for 10 minutes.
The output frequency is controlled by AC input current value
which is detected by T02 on the control P.C. board to prevent
the inverter input current rising higher than the specified
value.
Current value
1
(15A)
1
1
(14.5A)
2
A zone : The normal operation is executed.
D zone : The present operation frequency is kept.
B zone : The operation frequency is decreased.
C zone : Decrease of the operation frequency stopped, and
the present operation frequency is kept.
1) The heat sink temp. is detected by thermistor in the
compressor driving module Q200, and the inverter com-
pressor driver stops at 105°C.
2) When the inverter compressor driver stopped, 1 is counted
to the error count, and the error is determined with the
same error code 3 though reactivated after 2 minutes 30
seconds.
1) The compressor stops when T03 on IPDU control P.C.
board detects over-current.
2) When the compressor stopped, 1 is counted to the error
count, and the compressor reactivates after 2 minutes 30
seconds. After reactivated, the error count is cleared if the
operation continues for 10 minutes or more.
3) The error is determined with error code 8.
1) The compressor driver stops when high pressure SW at
inverter compressor operates.
2) When the compressor driver stops, 1 is counted to the
error count, and the compressor driver reactivates after 2
minutes 30 seconds. After reactivated, the error count is
cleared if the operation continues for 10 minutes or more.
3) The error is determined with error code 3.
B zone
C zone
D zone
A zone
3-33
Remarks