Hakim Eng
Electrical
- Dec 23, 2020
- 20
Hello guys,
i have a linear hydraulic cylinder controlled by a plc through 4-20 mA proportional valve.
The whole hydraulic system composed of:
- proportional valve.
- blocking valve.
- pressure switch " to ensure oil presence"
- a position transducer.
when trying to move the cylinder up/down it works perfectly, but when trying to position the cylinder at an intermediate position the load goes donw by the inertia effect even the blocking EV is not energized at all ?!
Also, when powering-off the machine,i left the cylinder at initial position " up ", and when coming next day, i found the cylinder at the bottom position even though no power was present.
What cause the cylinder to change it's position with no Electro-valve energized?
Any help please
Thanks in advance
i have a linear hydraulic cylinder controlled by a plc through 4-20 mA proportional valve.
The whole hydraulic system composed of:
- proportional valve.
- blocking valve.
- pressure switch " to ensure oil presence"
- a position transducer.
when trying to move the cylinder up/down it works perfectly, but when trying to position the cylinder at an intermediate position the load goes donw by the inertia effect even the blocking EV is not energized at all ?!
Also, when powering-off the machine,i left the cylinder at initial position " up ", and when coming next day, i found the cylinder at the bottom position even though no power was present.
What cause the cylinder to change it's position with no Electro-valve energized?
Any help please
Thanks in advance