Flowserve DFP17 - Manual (Page 31)

WCAIM2037 DataFlo Digital Electronic Positioner DFP17 Installation, Operation and Maintenance Instructions 31
Flow Control
Worcester Actuation Systems
CHECK ACTION NOTES AND CAUTIONS
7.3.10 Check temperature of motor(s). Allow the motor(s) to cool so Duty cycle is specified at an ambient
One AC motor has a thermal that the thermal switch can temperature of 70°F, 60 Hz.
cutout switch built-in that opens reset. Normally the thermal
at about 210°F (winding switch will not open unless
temperature). If the thermal the motor’s rated duty cycle is
cutout has opened, both motors exceeded and/or the ambient
are de-energized until the thermal temperature is very high.
switch resets (20-2375 sizes). Correct the problem.
7.3.11 Check the operating torque of the If operating torque of valve If the actuator is removed from a three-piece
valve. If necessary, remove the exceeds the specified torque valve that requires the body bolts to also be
actuator from the valve. Measure for the seats used and the DP removed, the valve body bolts must be
valve torque with an accurate across the valve, determine retorqued to specifications before checking
torque wrench. Check torque cause and correct. If torque valve torque. See Valve IOM.
under actual operating conditions falls within normal range, it
if possible. is possible that the actuator is
undersized.
7.3.12 Check ambient temperature. Actuator duty cycles are Higher ambient derates duty cycle.
specified at an ambient
temperature of 70°F.
7.3.13 Check to see that mechanical Replace defective mechanical All 2" CPT valves with Positioner boards in
brake is operating correctly. brake. If one was never actuator must have mechanical brake
installed, order a kit and installed to prevent oscillation.
install it in actuator.
7.3.14 Check to see if actuator can move If motor(s) cannot start, go to
a high torque valve from a stop next larger size actuator.
under load when moving in the
same direction as last command
(mechanical brake does not allow
motor(s) to unwind).
7.3.15 Check to see which direction of Replace circuit board.
travel causes problem. If actuator
is coming off open limit switch
(traveling CW) when it slows
down or stops, then either Q1 or
U1 is bad. If actuator is coming
off closed limit switch (traveling
CCW), then either Q2 or U2 is
bad. (AC boards only.)