10
2. Remove the o-ring from OUT1 and OUT2 port and
insert appropriate orifice. After inserting orifice, replace
the o-ring. Make sure there are not any substances
entering into the port. (Figure 21)
3. If hunting persists after inserting the orifice, please
contact CVS Controls Ltd. or its appropriate agent.
TROUBLESHOOTING
►Positioner does not respond to the input
signal.
1. Check supply pressure level. The lever must be at
least 1.4 kgf/cm2. For spring return type actuator, the
supply pressure level has to be larger than the spring’s
specification.
2. Check if the input signal is properly supplied to the
positioner. The signal should be 4~20mA DC.
3. Check if zero pint or span point is properly set.
4. Check if the positioners 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 for repair.
5. Check if the feedback lever has been installed
properly.
►The pressure of OUT1 reaches exhausting
pressure level and does not decrease.
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, pleae contact
CVS Controls Ltd.
►The pressure is exhausted only by the A/M
switch.
1. Check if the positioners 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 contact
CVS Controls Ltd.
►Linearity is too low
1. Check if the positioner is properly positioned.
Especially 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 the values is being adjusted,
another one must be adjusted as well.
3. Check if the 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 a double acting actuator, check if seat
adjustment has been properly performed. Please
contact CVS for any further inquiries regarding the
seat adjustment.
2. Backlash can ccur when the feedback lever and
lever spring loosen. To avoid backlashing, please
adjust the lever spring.
3. Check if the connection bar to the feedback lever is
tightly fastened.
CVS Controls Ltd.
Product Manual: CVS Rack & Pinion Actuator
CVS Controls Ltd.
Process Management
And Instrumentation
Orifice Diameter
Orifice
O - Ring (P5)
OUT2 OUT1
Actuator Size Orifice Size Suffix Symbol
90 cm3 less O 1 1
90 - 180 cm3O 2 2
180 cm3 more none 3
