OVERLOAD
PROTECTOR
8.
Working Principle
：
8.1 Press is normally operate:
When the press is normally operate, inner to have pressure control valve of overload
protector, which has the function of auto adjust hydraulic pressure. It can prevent effects
of excessive rising of hydraulic pressure caused by raised temperature when press is
operating.
8.2 When overload protector is releasing:
When overload occurs, overload protector will work to release excessive pressure
immediately. Meanwhile, it will out put electric signal to stop press immediately, and
the air solenoid valve, which is used by overload protector, will be“OFF”(cut off the
power supply).
8.3 After overload protector was released. (or hydraulic pressure isn
’
t enough):
After overload occurred, you have to eliminate the overload situation or to reset the
press; Meanwhile, the air solenoid valve is “ON” (electrify) to supplement oil of
cylinder to reach normal working pressure. Press will return to normal operation.
2005.07.08
SANDSUN
4
Circuit of Limit Switch
NO type(AT11-1-
I
)
NC
type(AT11-2-
I
） common
Press is normally
operate
14
13
22
21
OFF
14
13
22
21
ON
When overload
protector is
releasing
14
13
22
21
ON
14
13
22
21
OFF
After overload
protector was
released
(or hydraulic
pressure isn
’
t
enough)
14
13
22
21
ON
14
13
22
21
OFF