Hitachi RAM-60QH4 Manuel De Service page 94

5V
Reset circuit
DC 300-330V
Overload
external
setting circuit
Current
amplifier circuit
• The following gives details of operation for each circuit:
7-1. Peak current cut off circuit
Fig. 7-3 shows peak current cut off circuit and waveforms at each point.
DC current Id
27A
Voltage at point ◯
A
1.35V
◯
Voltage at point
B
• Ip cut circuit detects instantaneous surge current and stops inverter to protect components such as SPM.
• As shown in the diagram, when current exceeding 24A flows, voltage at point
to pin of INV-HIC, and voltage divided by R41 and R43 is input to pin
9
of IC1, LO is output from pin
stops drive output.
• When drive output of microcomputer stops, all drive outputs are set to HI and IC1 of HIC is initialized to enter drive
signal waiting status. Microcomputer again outputs drive signal 3 minutes later to re-start operation.
Reset voltage
Chopper
signal
DC current level
AX-6M00
◯ terminal
−
DC current
◯
A
Detection
R24
resistor
0V
(voltage at point
8
Chopper
signal
Ip signal
Fig. 7-2
SPM
HIC
IC1
R41
QC
9
9
C34
R43
0V 0V
Fig. 7-3
of IC1. Since this voltage exceeds threshold
9
). When LO is input to pin
B
– 106 –
Drive signal
Drive circuit
Peak
current
cut off
circuit
Detection resistor
B
CN14
9 2
20
R42
8
F
detected by detection resistor is input
A
of microcomputer, microcomputer
9
◯
＋
Compressor
motor
◯
−
Control P.W.B.
9
IP cutter
Outdoor
microcomputer