Overload Control Circuit (Ovl Control Circuit); Overload Control System Configuration - Hitachi RAM-55QH4 Service Manual

8. Overload control circuit (OVL control circuit)

Translation
To power module
negative
(R503)
Detection
resistor
Primary
CT
0V
terminal
Voltage amp.
circuit
(Internal judgement)
DC voltage
RC filter circuit
0V
Fig. 8-1 Overload Control System Configuration
Judgement value according to the rotation speed
AX-6S00 micro computer
Judgement OVL
with respect to
externally set
value
A/D
convarter
A/D
convarter
A/D
convarter
External judgement value
(internal judgement value)
Rotation speed
Fig. 8-2
– 90 –
Motor control
process
Judgement OVL
according to the rotation
speed
Selects data according
to the rotation speed and
DC voltage.
OVL start current data