Parameter Set-Up - Danfoss VLT HVACDrive Instruction Manual

7 How to Program the Adjustable Frequency
Drive

7.3.1 Parameter Set-up

Group Title
0- Operation and Display
1- Load / Motor
2- Brakes
3- Reference / Ramps
7
4- Limits / Warnings
5- Digital In / Out
6- Analog In / Out
8- Communication and Options Parameters used for configuring and monitoring functions associated with the serial communications /
9- Profibus
10- CAN Ser. Com. Bus
11- LonWorks
Table 7.1: Parameter Groups
7-50
Function
Parameters used to program the fundamental functions of the adjustable frequency drive and the LCP
including: selection of language; selection of which variables are displayed at each position in the display
(e.g., static duct pressure or condenser water return temperature can be displayed with the setpoint in
small digits in the top row and feedback in large digits in the center of the display); enabling/disabling
of the LCP keys/buttons; passwords for the LCP; upload and download of commissioned parameters to/
from the LCP and setting the built-in clock.
Parameters used to configure the adjustable frequency drive for the specific application and motor in-
cluding: open-loop or closed-loop operation; type of application such as compressor, fan or centrifugal
pump; motor nameplate data; auto-tuning of the drive to the motor for optimum performance; flying
start (typically used for fan applications) and motor thermal protection.
Parameters used to configure braking functions of the adjustable frequency drive which although not
common in many HVAC applications, can be useful on special fan applications. Parameters including: DC
braking; dynamic/resistor braking and overvoltage control (which provides automatic adjustment of the
deceleration rate (auto-ramping) to avoid tripping when decelerating large inertia fans)
Parameters used to program the minimum and maximum reference limits of speed (RPM/Hz) in open-
loop or in actual units when operating in closed-loop); digital/preset references; jog speed; definition of
the source of each reference (e.g., which analog input the reference signal is connected to); ramp-up
and ramp-down times and digital potentiometer settings.
Parameters used to program limits and warnings of operation including: allowable motor direction; min-
imum and maximum motor speeds (e.g., in pump applications it is typical to program a minimum speed
to approx 30–40% to ensure pump seals are adequately lubricated at all times, avoid cavitation and
ensure adequate head is produced at all times to create flow); torque and current limits to protect the
pump, fan or compressor driven by the motor; warnings for low/high current, speed, reference, and
feedback; missing motor phase protection; speed bypass frequencies including semi-automatic set-up
of these frequencies (e.g., to avoid resonance conditions on cooling towers and other fans).
Parameters used to program the functions of all digital inputs, digital outputs, relay outputs, pulse inputs
and pulse outputs for terminals on the control card and all option cards.
Parameters used to program the functions associated with all analog inputs and analog outputs for the
terminals on the control card and General Purpose I/O option (MCB101) (note: NOT Analog I/O option
MCB109, see parameter group 26-00) including: analog input live zero timeout function (which, for ex-
ample, can be used to command a cooling tower fan to operate at full speed if the condenser water
return sensor fails); scaling of the analog input signals (for example, to match the analog input to the
mA and pressure range of a static duct pressure sensor); filter time constant to filter out electrical noise
on the analog signal which can sometimes occur when long cables are installed; function and scaling of
the analog outputs (for example, to provide an analog output representing motor current or kW to an
analog input of a DDC controller) and to configure the analog outputs to be controlled by the BMS via a
high level interface (HLI) (e.g., to control a chilled water valve) including the ability to define a default
value of these outputs in the event of the HLI failing.
high level interface to the adjustable frequency drive
Parameters only applicable when a Profibus option is installed.
Parameters only applicable when a DeviceNet option is installed.
Parameters only applicable when a Lonworks option is installed.
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VLT ® HVAC Drive Instruction Manual