VLT
®
4000 VT
Programming
115 DC braking time
(DC BRAKE TIME)
Value:
0.0 - 60.0 sec.
✭
OFF
Function:
This parameter is for setting the DC braking time
for which the DC braking current (parameter
113) is to be active.
Description of choice:
Set the desired time.
116 DC brake cut-in frequency
(DC BRAKE CUT-IN)
Value:
0.0 (OFF) - par. 202
Output frequency high limit, f
MAX
✭
OFF
Function:
This parameter is used for setting the DC brake cut-in
frequency at which DC braking is to be activated
in connection with a stop command.
Description of choice:
Set the desired frequency.
117 Motor thermal protection
(MOT. THERM PROTEC)
Value:
No protection (NO PROTECTION)
[0]
Thermistor warning (THERMISTOR WARNING)
[1]
Thermistor trip (THERMISTOR FAULT)
[2]
ETR Warning 1 (ETR WARNING 1)
[3]
✭
ETR Trip 1 (ETR TRIP 1)
[4]
ETR Warning 2 (ETR WARNING 2)
[5]
ETR Trip 2 (ETR TRIP 2)
[6]
ETR Warning 3 (ETR WARNING 3)
[7]
ETR Trip 3 (ETR TRIP 3)
[8]
ETR Warning 4 (ETR WARNING 4)
[9]
ETR Trip 4 (ETR TRIP 4)
[10]
Function:
The AFD is able to monitor the motor temperature
in two different ways:
-
Via a thermistor sensor fitted to the motor. The
thermistor is connected to one of the analog
input terminals 53 and 54.
-
Calculation of the thermal load (ETR - Electronic
Thermal Relay), based on the current load and
the time. This is compared with the rated motor
current I
M,N
and the rated motor frequency f
M,N
.
The calculations made take into account the
need for a lower load at lower speeds because
of less cooling in the motor itself.
ETR functions 1-4 do not start calculating the load until
there is a switch-over to the Setup in which they were
selected. This enables the use of the ETR function,
even where two or several motors alternate.
Description of choice:
Select
No protection
[0] if no warning or tripping is
required when the motor is overloaded.
Select
Thermistor warning
[1] if a warning is desired
when the connected thermistor gets too hot.
Select
Thermistor trip
[2] if cutting out (trip) is desired
when the connected thermistor overheats.
Select
ETR Warning 1-4
, if a warning is to come
up on the display when the motor is overloaded
according to the calculations.
The AFD can also be programmed to give off a
warning signal via one of the digital outputs.
Select
ETR Trip 1-4
if tripping is desired when the
mo-tor is overloaded according to the calculations.
NOTE
In UL / cUL applications ETR provides class
20 motor overload profection in accordance
with National Electrical Code.
MG.40.A7.22 - VLT is a registered Danfoss trademark
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