In order to maintain PELV, all connections made to the
control terminals must be PELV, e.g. thermistor must be
reinforced/ double insulated
NOTE
Danfoss recommends using 24 VDC as thermistor supply
voltage.
1-93 Thermistor Source
Option:
Function:
Select the input to which the thermistor
(PTC sensor) should be connected. An
analog input option [1] or [2] cannot be
selected if the analog input is already in use
as a reference source (selected in
par. 3-15
Reference 1 Source
,
par. 3-16
Reference 2 Source
or
par. 3-17
Reference 3 Source
).
When using MCB 112, choice [0]
None
must
always be selected.
[0]
*
None
[1]
Analog input 53
[2]
Analog input 54
[3]
Digital input 18
[4]
Digital input 19
[5]
Digital input 32
[6]
Digital input 33
NOTE
This parameter cannot be adjusted while the motor is
running.
NOTE
Digital input should be set to [0]
PNP - Active at 24V
in
par. 5-00.
2-00 DC Hold/Preheat Current
Range:
Function:
50 %
*
[Applica-
tion
dependant]
Enter a value for holding current as a
percentage of the rated motor current I
M,N
set in par. 1-24
Motor Current
. 100% DC
holding current corresponds to I
M,N
.
This parameter holds the motor (holding
torque) or pre-heats the motor.
This parameter is active if [1] DC hold/
Preheat is selected in par. 1-80
Function at
Stop
.
NOTE
The maximum value depends on the rated motor
current.
Avoid 100 % current for too long. It may damage the
motor.
2-10 Brake Function
Option:
Function:
[0]
*
Off
No brake resistor installed.
[1]
Resistor
brake
Brake resistor incorporated in the system, for
dissipation of surplus brake energy as heat.
Connecting a brake resistor allows a higher DC
link voltage during braking (generating
operation). The Resistor brake function is only
active in frequency converters with an integral
dynamic brake.
[2]
AC brake
AC Brake will only work in Compressor Torque
mode in par. 1-03
Torque Characteristics
.
2-16 AC brake Max. Current
Range:
Function:
100.0 %
*
[Application
dependant]
Enter the maximum permissible
current when using AC brake to avoid
overheating of motor windings. The AC
brake function is available in Flux
mode only (FC 302 only).
2-17 Over-voltage Control
Option:
Function:
Over-voltage control (OVC) reduces the risk of the
frequency converter tripping due to an over
voltage on the DC link caused by generative power
from the load.
[0]
Disabled No OVC required.
[2]
*
Enabled
Activates OVC.
NOTE
The ramp time is automatically adjusted to avoid
tripping of the frequency converter.
3-02 Minimum Reference
Range:
Function:
Applica-
tion
depend-
ent
*
[Applica-
tion
dependant]
Enter the Minimum Reference. The
Minimum Reference is the lowest value
obtainable by summing all references.
The Minimum Reference value and unit
matches the configuration choice made
in par. 1-00
Configuration Mode
and
par. 20-12
Reference/Feedback Unit
,
respectively.
NOTE
This parameter is used in open
loop only.
How to Programme the Frequ...
VLT
®
HVAC Drive Operating Instructions
MG.11.AD.02 - VLT
®
is a registered Danfoss trademark
73
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