Danfoss VLT HVAC Drive FC 102 Instruction Manual page 79

How to Program
Group Title
20-** FC Closed-loop
21-** Extended Closed-loop
22-** Application Functions
23-** Time-based Functions
MG11F522
Instruction Manual
Function
Parameters used to configure the closed-loop PI(D) controller, which controls the speed of the
pump, fan or compressor in closed-loop mode including:
•
Defining where each of the three possible feedback signals come from (for example, which
analog input or the BMS HLI).
•
Conversion factor for each of the feedback signals. An example could be a pressure signal
used for indication of flow in an AHU or converting from pressure to temperature in a
compressor application).
•
Engineering unit for the reference and feedback (for example, Pa, kPa, m Wg, in Wg, bar,
m3/s, m3/h, °C, °F, etc).
•
The function (for example, sum, difference, average, minimum or maximum) used to calculate
the resulting feedback for single-zone applications or the control philosophy for multi-zone
applications.
•
Programming of the setpoints.
•
Manual tuning or auto-tuning of the PI(D) loop.
Parameters used to configure the three extended closed-loop PI(D) controllers. The controllers
can, for example, be used to control external servos (for example, chilled water valve to maintain
supply air temperature in a VAV system) including:
•
Engineering unit for the reference and feedback of each controller (for example, °C, °F).
•
Defining the range of the reference/setpoint for each controller.
•
Defining where each of the references/setpoints and feedback signals come from (for
example, which analog input or the BMS HLI).
•
Programming of the setpoint, and manual tuning or auto-tuning of each of the PI(D)
controllers.
Parameters used to monitor, protect and control pumps, fans and compressors, including:
•
No-flow detection and protection of pumps (including auto-setup of this function).
•
Dry-pump protection.
•
End-of-curve detection and protection of pumps.
•
Sleep mode (especially useful for cooling tower and booster pump sets).
•
Broken-belt detection (typically used for fan applications to detect no air flow instead of
using a ∆p switch installed across the fan).
•
Short-cycle protection of compressors and pump flow compensation of setpoint (especially
useful for secondary chilled water pump applications where the ∆p sensor has been installed
close to the pump and not across the furthest most significant load(s) in the system.
•
Using this function can compensate for the sensor installation and help to realize the
maximum energy savings).
Time-based parameters including:
•
Parameters used to initiate daily or weekly actions based on the built-in real time clock. The
actions could be change of setpoint for night set-back mode or start/stop of the pump/fan/
compressor start/stop of an external equipment).
•
Preventive maintenance functions, which can be based on running or operating hour time
intervals or on specific dates and times.
•
Energy log (especially useful in retrofit applications or where information of the actual
historical load (kW) on the pump/fan/compressor is of interest).
•
Trending (useful in retrofit or other applications where there is an interest to log operating
power, current, frequency or speed of the pump/fan/compressor for analysis and a payback
counter.
Danfoss A/S © 08/2014 All rights reserved.
6 6
77