Danfoss VLT FC 100 Operating Instructions Manual page 93

6 How to Programme
Group Title
14** Special Functions
15** FC Information
6
16** Data Readouts
18** Info & Readouts
20** FC Closed Loop
21** Extended Closed Loop
22** Application Functions
23** Time Based Functions
24** Application Functions 2
92
Function
the outside air relative humidity and supply air temperature via it's analog inputs and controlling the
chilled water valve via one of the extended PI(D) loops and an analog output, it would then modulate
that valve to maintain a higher supply air temperature). The SLC can often replace the need for other
external control equipment.
Parameters used to configure special functions of the frequency converter including: setting of the
switching frequency to reduce audible noise from the motor (sometimes required for fan applications);
kinetic back-up function (especially useful for critical applications in semi-conductor installations where
performance under mains dip/mains loss is important); mains imbalance protection; automatic reset
(to avoid the need for a manual reset of Alarms); energy optimisation parameters (which typically do
not need changing but enable fine tuning of this automatic function (if necessary) ensuring the fre-
quency converter and motor combination operate at their optimum efficiency at full and partial load
conditions) and auto-derating functions (which enable the frequency converter 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 inden-
tification parameters such as code number and software version.
Read only parameters which display the status/value of many operating variables which can be dis-
played on the LCP or viewed in this parameter group. These parameters can be particularly useful
during commissioning when interfacing with a BMS via a high level interface.
Read only parameters which display the last 10 prevantative 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 3 possible feedback sig-
nals 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 pres-
sure 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 philosophy for multi-zone applications; programming of the setpoint(s) and manual or auto-
tuning of the PI(D) loop.
Parameters used to configure the 3 extended closed loop PI(D) controllers which for example can be
used to control external actuators (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 ref-
erences/setpoints and feedback signals come from (e.g. which analog input or the BMS HLI); pro-
gramming of the setpoint and manual or auto-tuning of the 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 acoss the furthest most significant load(s) in the
system; using this function can compensate for the sensor installation and help to realise the maxi-
mum 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 (espe-
cially 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.
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VLT HVAC Drive High Power Operating In-
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