Danfoss VLT CDS 303 User Manual

28-20 Temperature Source
Option: Function:
Low Voltage to parameter 6-25 Terminal 54 High
Ref./Feedb. Value to match the characteristics of
the device.
[3] Bus The actual discharge temperature should be sent
via Modbus RTU or FC protocol to 28-27
Discharge temperature. The temperature could be
set via PCD write in parameter 8-42 PCD Write
Conguration.
28-21 Temperature Unit
Option: Function:
Selects the unit of the discharge temperature.
[60 ] * ˚C
[160] ˚F
28-24 Warning Level
Range: Function:
130
*
[10–
parameter 28-26 Emergency
Level]
Selects the temperature at
which a warning shall be
issued. The action selected in
parameter 28-25 Warning Action
becomes active at this
temperature. Enter the
temperature measured in the
unit selected in
parameter 28-21 Temperature
Unit.
28-25 Warning Action
Option: Function:
Selects the action to be taken by the frequency
converter for discharge temperatures above the
value programmed in
parameter 28-21 Temperature Unit but below the
value programmed in parameter 28-26 Emergency
Level.
[0] None No action. Only a warning is issued.
[1]
*
Decrease
cooling
A warning is issued and the motor speed is
lowered in steps of 10 Hz every 3 minutes until
the temperature either drops below the level
programmed in parameter 28-24 Warning Level or
exceeds the level programmed in
parameter 28-26 Emergency Level.
28-26 Emergency Level
Range: Function:
145*
[parameter 28-24 Warning
Level-300]
Selects the temperature at
which an alarm shall be issued.
Enter the temperature in the
unit programmed in
parameter 28-21 Temperature
Unit.
28-27 Discharge Temperature
Range: Function:
0* [-2147483648 –
2147483648]
Returns the actual value of the
discharge temperature.
6.15.4 28-3* Crankcase Heating
A DC-hold Current through the motor windings can be
used as an alternative to an external crankcase heater to
keep the compressor warm when stopped.
The eciency of the Crankcase Heating depends upon the
physical placing of the actual motor in the compressor.
If the Crankcase Heating is used together with Anti-Reverse
Protection, the frequency converter
rst brakes for the set
duration followed by the heating current.
28-30 Crankcase Heating Control
Option: Function:
Activate the DC-hold current when the motor is
stopped. The current level is dened in
parameter 28-31 Heating DC Current.
[0] * Disabled
[1] Enabled
28-31 Heating DC Current
Range: Function:
20% * [0 – 25%] Set the DC-hold current as percentage of the
rated motor current in parameter 1-24 Motor
Current.
28-32 Crankcase Heating Delayed
Range: Function:
5 s* [5-65534 s] This time denes the delay after a stop and
until Crank Case Heating is applied to the
compressor.
6.15.5 28-4* Anti-reverse Protection
A compressor may have a preferred rotation direction and
the instructions for cabling should always be followed, but
the consequences of a reverse rotation are normally not
fatal. Set up parameter group 28-4* Anti-reverse Protection
to prevent reverse rotation at stop by injecting a DC-brake
current into the motor a few seconds after stop followed
by the eventual coast of the motor when the discharge
valve has closed.
Parameter Descriptions
VLT
®
Compressor Drives CDS 302/CDS 303
124 Danfoss A/S © Rev. 2013-07-03 All rights reserved. MG34M422
6
6

Danfoss VLT CDS 303 Specifications

General

Brand	Danfoss
Model	VLT CDS 303
Category	DC Drives
Language	English