Toshiba HFCR407C - IPDU (Inverter) Control

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11
Item Operation explanation and applied data, etc. Remarks
11. IPDU (Inverter) IPDU controls the inverter compressor by command frequency, frequency up/down
control speed, and current release control value from the interface PC board. The main controls
of IPDU control PC board are described below.
(1) Current release control
The output frequency is controlled by AC input current value which is detected by
T02 on the control PC board, to prevent the inverter input current dropping lower
than the specified value.
Outline of control
Outdoor units
Current value
(22A) I
1
(21.5A) I
2
B zone
C zone
A zone
D zone
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.
(2) Heat sink temp. detection control
1) The heat sink temp. is detected by the thermistor in the compressor driving
module Q200, and the inverter compressor driver stops when 120°C is detected.
2) When the inverter compressor driver stops, 1 is counted to the error count. If
the error count reaches 3 the system generates a fault code and system
operation stops.
NOTE:
When the error has been determined, the ambient outdoor temp. or an outdoor fan error
is considered.
(3) Over-current protective control
1) The compressor stops when T03 on IPDU control PC board detects
over-current.
2) When the compressor stops, 1 is counted to the 2 minutes 30 seconds. After
reactivation, the error count is cleared if the operation continues for 10 minutes
or more.
(4) High pressure SW control
1) The compressor driver stops when the inverter compressor high pressure
SW 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 reactivation, the
error count is cleared if the operation continues for 10 minutes or more.