Danfoss VLT HVAC Operating Instructions Manual page 66

6. How to programme the frequency converter
Function:
Sets the time format to be used in the LCP.
0-74
Value:
OFF
Manual
Function:
Choose how Daylight Saving Time/Summer-
time should be handled. For manual DST/
Summertime enter the start date and end date
in par. 0-76 and 0-77.
6
0-76
Value:
2000-01-01 00:00 –
2099-12-31 23:59
Function:
Sets the date and time when summertime/
DST starts. The date is programmed in the
format selected in par. 0-71.
0-77
Value:
2000-01-01 00:00 –
2099-12-31 23:59
Function:
Sets the date and time when summertime/
DST ends. The date is programmed in the for-
mat selected in par. 0-71.
1-00
Value:
Open loop
Closed loop
Function:
Open Loop
applying a speed reference or by setting de-
sired speed when in Hand Mode.
Open Loop is also used if the frequency con-
verter is part of a closed loop control system
66
DST/Summertime
DST/Summertime Start
2000-01-01
00:00
DST/Summertime End
2000-01-01
00:00
Configuration Mode
[0]: Motor speed is determined by
MG.11.A4.02 - 09.10.06. VLT
®
VLT HVAC Drive Operating Instructions
based on an external PID controller providing
a speed reference signal as output.
Closed Loop
[3]: Motor Speed will be deter-
mined by a reference from the built-in PID
controller varying the motor speed as part of
a closed loop control process (e.g. constant
pressure or temperature). The PID controller
must be configured in par. 20-**, Drive Closed
[0]
Loop or via the Function Setups accessed by
[2]
pressing the [Quick Menus] button.
This parameter can not be changed when mo-
tor is running.
1-03 Torque Characteristics
Value:
Compressor
Variable torque
Auto energy optim. compressor
Auto energy optim. VT
Function:
Compressor
[0]: For speed control of screw
and scroll compressors. Provides a voltage
which is optimized for a constant torque load
characteristic of the motor in the entire range
down to 15 Hz.
Variable Torque [1]: For speed control of cen-
trifugal pumps and fans. Also to be used when
controlling more than one motor from the
same frequency converter (e.g. multiple con-
denser fans or cooling tower fans).Provides a
voltage which is optimized for a squared tor-
que load characteristic of the motor.
Auto Energy Optimization Compressor
For optimum energy efficient speed control of
screw and scroll compressors. Provides a volt-
age which is optimized for a constant torque
load characteristic of the motor in the entire
range down to 15Hz but in addition the AEO
feature will adapt the voltage exactly to the
current load situation, thereby reducing ener-
gy consumption and audible noise from the
[0]
motor. To obtain optimal performance, the
[3]
motor power factor cos phi must be set cor-
rectly. This value is set in par. 14-43, Motor
cos phi. The parameter has a default value
which is automatically adjusted when the mo-
tor data is programmed. These settings will
typically ensure optimum motor voltage but if
the motor power factor cos phi requires tun-
ing, an AMA function can be carried out using
® is a registered Danfoss trademark
[0]
[1]
[2]
[3]
[2]: