Danfoss VLT Instruction Manual page 110

6 How to program the adjustable frequency
drive
Group Title
14- Special Functions
15- FC Information
16- Data Readouts
18- Info & Readouts
20- FC Closed-loop
6
21- Extended Closed-loop
22- Application Functions
23- Time-based Functions
24- Application Functions 2
25- Cascade Controller
26- Analog I/O Option MCB 109 Parameters used to configure the Analog I/O option (MCB109) including: definition of the analog input
Parameter descriptions and selections are displayed on the graphic (GLCP) or numeric (NLCP) display. (See the relevant section for details.) Access the
parameters by pressing the [Quick Menu] or [Main Menu] button on the control panel. The quick menu is used primarily for commissioning the unit at
start-up by providing the parameters necessary to start operation. The main menu provides access to all the parameters for detailed application pro-
gramming.
All digital input/output and analog input/output terminals are multifunctional. All terminals have factory default functions suitable for the majority of HVAC
applications but if other special functions are required, they must be programmed as explained in parameter group 5 or 6.
6-52
Function
Parameters used to configure special functions of the adjustable frequency drive including: setting of
the switching frequency to reduce audible noise from the motor (sometimes required for fan applica-
tions); kinetic back-up function (especially useful for critical applications in semi-conductor installations
where performance under line power dip/line power loss is important); line imbalance protection; au-
tomatic reset (to avoid the need for a manual reset of alarms); energy optimization parameters (which
typically do not need changing but enable fine tuning of this automatic function (if necessary) ensuring
the adjustable frequency drive and motor combination operate at their optimum efficiency at full and
partial load conditions) and auto-derating functions (which enable the adjustable frequency drive to
continue operation at reduced performance under extreme operating conditions ensuring maximum up
time).
Parameters providing operating data and other drive information including: operating and running hour
counters; kWh counter; resetting of the running and kWh counters; alarm/fault log (where the past 10
alarms are logged along with any associated value and time) and drive and option card indentification
parameters such as code number and software version.
Read only parameters which display the status/value of many operating variables which can be displayed
on the LCP or viewed in this parameter group. These parameters can be particularly useful during com-
missioning when interfacing with a BMS via a high level interface.
Read-only parameters which display the last 10 preventative maintenance log items, actions and time
and the value of analog inputs and outputs on the analog I/O option card which can be particularly useful
during commissioning when interfacing with a BMS via a high level interface.
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 (e.g., which analog input or the BMS HLI); conversion factor for each of the feedback
signals (e.g., where a pressure signal is 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 (e.g., Pa,
kPa, m Wg, in Wg, bar, m3/s, m3/h, °C, °F, etc.); the function (e.g., sum, difference, average, minimum
or maximum) used to calculate the resulting feedback for single zone applications or the control philos-
ophy for multi-zone applications; programming of the setpoint(s) and manual or auto-tuning of the PI(D)
loop.
Parameters used to configure the three extended closed-loop PI(D) controllers which, for example, can
be used to control external servos (e.g., chilled water valve to maintain supply air temperature in a VAV
system) including: engineering unit for the reference and feedback of each controller (e.g., °C, °F, etc.);
defining the range of the reference/setpoint for each controller; defining where each of the references/
setpoints and feedback signals come from (e.g., which analog input or the BMS HLI); programming of
the setpoint and manual or auto-tuning of each of the PI(D) controllers.
Parameters used to monitor, protect and control pumps, fans and compressors including: no flow de-
tection 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 com-
pensation 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 achieve maximum
energy savings).
Time based parameters including: those used to initiate daily or weekly actions based on the built-in real
time clock (e.g., change of setpoint for night set back mode or start/stop of the pump/fan/compressor
start/stop of a external equipment); preventative 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 (especially 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.
Parameters used to set up fire mode and/or to control a bypass contactor/starter if designed into the
system.
Parameters used to configure and monitor the built-in pump cascade controller (typically used for pump
booster sets).
types (e.g., voltage, Pt1000 or Ni1000) and scaling and definition of the analog output functions and
scaling.
MG.11.A9.22 - VLT ® is a registered Danfoss trademark
VLT ® HVAC Drive Instruction Manual