TROUBLESHOOTING GUIDE Troubleshooting guide
PROBLEM
SEE CAUSES AND SOLUTIONS BELOW
The shaft turns slowly or not at all
1-6
The machine operates irregularly or does not respond
7
The shaft does not turn completely
8-9
The selected position cannot be maintained
3-4-7
CAUSE
SOLUTION
1. Insufficient output torque
Check the operating pressure. Do not exceed the original manufacturer’s recommended pressure. The load may be greater than the actuator’s maximum capacity.
2. Low fluid flow
Check whether the holes are blocked and that there are no restrictions or leaks in the hydraulic lines.
3. Internal leak in the control or balancing valve
Disconnect the hydraulic lines and the by-pass valve. Leave the holes open and operate the actuator via the holes in the casing (do not exceed the original manufacturer’s operating pressure). The valve must be replaced if there is a constant flow of fluid from the valve’s holes.
4. Leak from the shaft or piston seal
Remove the plug and the valve holes from the casing. Operate the actuator via the holes in the casing. Test for internal leaks as indicated in the Testing section on page 22 of this manual.
5. Corrosion accumulated on the thrust surfaces
Recondition the actuator. Remove all the rust and polish the surfaces.*
6. Blown seals and composite bearings caused by incompatible hydraulic fluid (standard actuators only)
Recondition the actuator. Use a fluid compatible with the seals and bearings. Contact Helac for any additional information.
7. Air in the actuator
Bleed the air from the actuator. Consult the bleeding procedure, starting on page 23.
8. Deformed or chipped teeth on the grooves due to an overload
Check that the grooves are not jammed. It may not be possible to recondition the actuator: it may have to be replaced.
9. The connections for the holes create an obstruction while the piston is travelling
Check the length of the thread on these connections. The connections should not reach the inside of the casing’s bore during travel.
* Replacement parts may be required
24
