Electro-Pneumatic Positioner YT-1000R Trouble Shooting Manual
Young Tech Co. #662-8 PumgMu Dong, Kimpo City, (415-809) Korea (031) 986-4935 www.ytc.co.kr
Troubleshooting
▶ Positioner does not respond to the input signal.
(1)
Check supply pressure level.
The lever must be at least 1.4 kgf/cm
2.
For spring-return
type of actuator, the supply pressure level has to be larger than the spring's
specification.
(2)
Check if input signal is properly supplied to the positioner.
The signal should be
4~20mA DC.
(3)
Check if zero point or span point is properly set.
(4)
Check if the positioner's nozzle has been blocked.
Also, check if the pressure is
supplied to the positioner and the pressure is being exhausted through the nozzle.
If
the nozzle has been block by any substances, please send the product for repair.
(5)
Check if feedback lever has been installed properly.
▶ The pressure of OUT1 reaches exhausting pressure level and does not come back down.
(1)
Check A/M Switch.
If the switch has been damaged, replace the switch or pilot relay
valve.
(2)
Check for a gap or damages between the nozzle and the flapper.
If damaged, please
send the product to YTC for repair.
▶ The pressure is exhausted only by A/M Switch.
(1)
Check if the positioner's nozzle has been blocked.
Also, check if the pressure is
supplied to the positioner and the pressure is being exhausted through the nozzle.
If
the nozzle has been blocked by any substances, please send the product to YTC for
repair.
▶ Hunting occurs.
(1)
Check if safety spring has been displaced.
(Next to Pilot relay valve)
(2)
Check if the size of actuator is too small.
If so, insert an orifice in order to reduce the
pressure flow rate.
(3)
Check if there is any friction between the valve and the actuator.
If so, increase
actuator's size or reduce the friction level.
▶ Actuator only operates by On/Off.
(1)
Check actuator and positioner's acting type.
Air pressure exhausts from YT-1000L's
OUT1 port as input signal level increases.
Therefore, it is standard to connect to OUT1
port when single actuator is used.
Make sure the span adjustment is properly set
according to the valve system.
▶ Linearity is too low.
(1)
Check if positioner is properly positioned.
Especially check if the feedback lever is
parallel to the ground at 50% point.
(2)
Check if zero and span point have been properly adjusted.
If either one of values is
being adjusted, another one must be re-adjusted as well.
(3)
Check if supply air pressure level is stable from the regulator.
If the level is unstable,
the regulator must be replaced.
▶ Hysteresis is too low.
(1)
In case of double acting actuator, check if seat adjustment has been properly
performed.
Please contact YTC for any further inquiries regarding the seat adjustment.
