Page
5
of
18
①
TORQUE LIMITER ACTIVATED
REPORTED FAULT
POSSIBLE REASON(S) POSSIBLE SOLUTIONS/ ADVICE
LED Flashing
Electronic torque
limiter (ETL) has
activated
• Electronic Torque Limiter (ETL) activated
.
ETL function: An internal micro-processor monitors the current draw and is programmed to cut the motor power if the upper current set
point is reached and that the rate of increase exceeds a maximum allowable rate. Once the power to the motor is cut, the LED blinks (see
Page 2) and the gearbox is relaxed by a 5 degree movement in the opposite direction to that which activated the ETL.
•
The ETL activation could be caused by either (or sometimes both) the valve, or the actuator:
The torque in the valve exceeds the trigger point of the ETL. This could be due to;
•
Actuator undersized for the torque in the valve, or
•
Actuator undersized for the application – dry duty, air, steam solids, long periods of no operations etc
•
A blockage in the valve
•
A valve internal issue that has caused the torque to rise (eg: seat failure)
Whilst the ETL protects the gearbox from mechanical damage caused by a valve blockage, if the blockage is not investigated and the
actuator’s ETL is activated excessively (this can be identified from the electronic counters that can be read by J+J service centres,
comparing torque limiter activations to number of operations), it is possible that eventually the gearbox will fail mechanically. This is not a
warranty issue because it is customer generated by not resolving the excessive torque issue.
Quick check 1:
•
Put the actuator in ‘MANUAL’ and try to operate the valve using the actuator’s hand wheel. DON’T FORCE IT if it is stiff – this is a strong
indicator the issue is with the valve. If the gearbox is blocked in mid travel – this is a sure sign the gearbox has failed.
Be aware that the gearing system in the manual override system would allow destructive force to be transmitted if there was a blockage
and the hand-wheel was forced – this would physically damage either the manual override hand wheel drive shaft (plastic) or gears in the
gearbox and the actuator would be irreparable. This damage is not covered under warranty.
Quick check 2:
•
Remove the actuator from the valve, re-apply power, first apply an open signal, then a closed signal.
2a) If the LED lights continuously,
the issue is valve related
, and the valve should be removed from the line, stripped and re-assembled with
new seats and seals and/or any other parts required, or replaced.
