Sierra 840 User Manual
Chapter 4 Maintenance
Series 830/840/860 Instruction Manual
4-14
IM-83/84/86-H
slowly, 1/8 turn at a time and observe until the desired voltage
is obtained.
is obtained.
4. Now apply a 5% setpoint signal and confirm that the voltage
does not drop below 11 volts on the 30-volt circuit or 6 volts
on the 15-volt circuit. Go back and forth between these set-
tings and make sure that the voltages stay within these bounda-
ries. When this voltage “window” is obtained, the symptoms
should disappear and the lock nut can be re-tightened.
on the 15-volt circuit. Go back and forth between these set-
tings and make sure that the voltages stay within these bounda-
ries. When this voltage “window” is obtained, the symptoms
should disappear and the lock nut can be re-tightened.
5. Re-install the electronics cover by powering down the control-
ler, removing the cable, putting the cover back on and replac-
ing the access door plugs. Reconnect the cable and apply the
power. A final check for leak-by with a zero set point and
proper flow with various control signals should be conducted.
ing the access door plugs. Reconnect the cable and apply the
power. A final check for leak-by with a zero set point and
proper flow with various control signals should be conducted.
Notes: Adjusting the valve voltage does not change the
calibration of the controller. If these adjustments do not
obtain the desired operation, contact Sierra directly.
calibration of the controller. If these adjustments do not
obtain the desired operation, contact Sierra directly.