Thermo Scientific ALPHA PH 2000 Manual page 33

- OFF = controller off
Use control Off to operate controller as a monitor only or to prevent relays
from switching.
- L.CT = limit value control (on/off control).
Use limit control with pumps or values for fast response
- P/PI = proportional/integral control
Use proportional control to operate your pumps smoothly or for precise
control of proportioning valves. Use PI controller to eliminate steady state
error.
Note: please refer to Appendix 4 for detailed information on controller
settings.
Press the ENT key to confirm your selection.
If the controller is set to limit value control (L.CT):
3. Selecting the relay status under Non-Alarm condition: press the ▲ or
▼ key to choose the desired relay status (de-energized = "DEEN" or
energized = "EN"). Press the ENT key to confirm your selection.
- If the controller is set to proportional control (P/PI):
4. Selecting the proportional controller type: press the ▲ or ▼ key to
select the suitable controller type ("PLC" = pulse length control, "PFC" =
pulse frequency control).
Press the ENT key to confirm your selection.
If the proportional controller type is set to pulse length control (PLC):
5. Selecting the relay status under Non-Alarm condition: press the ▲ or
▼ key to choose the desired relay status (de-energized = "DEEN" or
energized = "EN"). Press the ENT key to confirm your selection.
6. Setting the proportional range. Press the ▲ or ▼ key to set the
proportional range (setting range: 10 to 500%). Press the ENT key to
confirm your setting.
7. Setting the pulse length. Press the ▲ or ▼ key to set the pulse length
(setting range: 0.5 to 20 seconds). Press the ENT key to confirm your
setting.
8. Setting the integral action time. Press the ▲ or ▼ key to set the
integral action time (setting range: 0.0 to 999.9 minutes). Press the ENT
key to confirm your setting.
Note: If the integral action time is set to '0.0', then the unit functions as a
'P' Controller.
If the proportional controller type is set to pulse frequency control (PFC):
9. Selecting the relay status under Non-Alarm condition: press the ▲ or
▼ key to choose the desired relay status (de-energized = "DEEN" or
energized = "EN"). Press the ENT key to confirm your selection.