Electro-Pneumatic Positioner
YT-1000 / 1050 series
Product Manual
Ver. 1.30
73
9
Troubleshooting
➢
Positioner does not respond to the input signal.
1)
Check supply pressure level. The lever must be at least 0.14 MPa(1.4 bar). 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 ~ 20 mA 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 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 Supply pressure level and does not come back down.
1)
Check auto manual 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 the corresponding local Rotork YTC Limited office or main office in South Korea for
repair.
➢
The pressure is exhausted only by Auto manual 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 the corresponding local Rotork YTC Limited office
or main office in South Korea for repair.
➢
Hunting occurs.
1)
Check if stabilizing spring has been displaced. (Next to Pilot unit)
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.
➢
The actuator moves only to full open and full close positions.
1)
Check if Span or Cam of the positioner is installed correctly corresponding to direct or reverse
acting of the actuator. If not, refer to 7.1.1 or 7.1.2 section.
