GEA ARIETE, Instructions For Use And Maintenance Manual

Page: 452 / 556

VLT
®
5000 Series
nal 27 or via a serial communication port. The DC
braking current will be active for the duration of the
DC braking time set in parameter 126.
NB!:
The maximum value depends on the rated
motor current. If the DC braking current is ac-
tive, the VLT frequency converter has a switching
frequency of 4.5 kHz.
Description of choice:
To be set as a percentage value of the rated motor
current I
M,N
set in parameter 105.
100% DC braking current corresponds to I
M,N
.
Warning: 100 % sup-
ply for too long may damage the motor.
126
126 DC braking time
(DC BRAKING TIME)
Value:
0.0 (OFF) - 60.0 sec.
✭
10.0 sec.
Function:
This parameter is for setting the DC braking time for
which the DC braking current (parameter 125) is to
be active.
Description of choice:
Set the desired time.
127
127 DC brake cut-in frequency
(DC BRAKE CUT-IN)
Value:
0.0 - parameter 202
✭
0.0 Hz (OFF)
Function:
This parameter is for setting the DC brake cut-in fre-
quency at which the DC braking current (parameter
125) is to be active, in connection with a stop com-
mand.
Description of choice:
Set the desired frequency.
128 128 Motor thermal protection
(MOT.THERM PROTEC)
Value:
✭
No protection (NO PROTECTION)
[0]
Thermistor warning (THERMISTOR WARN)
[1]
Thermistor trip (THERMISTOR TRIP)
[2]
ETR Warning 1 (ETR WARNING1)
[3]
ETR Trip 1 (ETR TRIP1)
[4]
ETR Warning 2 (ETR WARNING2)
[5]
ETR Trip 2 (ETR TRIP2)
[6]
ETR Warning 3 (ETR WARNING3)
[7]
ETR Trip 3 (ETR TRIP3)
[8]
ETR Warning 4 (ETR WARNING 4)
[9]
ETR Trip 4 (ETR TRIP4)
[10]
Function:
The VLT frequency converter is able to monitor the
motor temperature in two different ways:
- Via a thermistor sensor connected to one of the
analogue inputs, terminals 53 and 54 (parame-
ters 308 and 311).
- Calculation of the thermal load, based on the cur-
rent load and the time. This is compared with the
rated motor current I
M,N
and the rated motor fre-
quency f
M,N
. The calculations made take into
account the need for a lower load at lower
speeds because of less cooling from the fan.
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.
For the North American market: The ETR functions
provide class 20 motor overload protection in accor-
dance with NEC.
Description of choice:
Select No protection if no warning or tripping is re-
quired when the motor is overloaded.
Select Thermistor warning if a warning is desired
when the connected thermistor - and thus the motor
- gets too hot.
Select Thermistor trip if cutting out (trip) is desired
when the connected thermistor - and thus the motor
- overheats.
Select ETR Warning 1-4 , if a warning is to come up
on the display when the motor is overloaded accord-
ing to the calculations.
Select ETR Trip 1-4 if tripping is desired when the
motor is overloaded according to the calculations.
The VLT frequency converter can also be pro-
grammed to give off a warning signal via one of the
digital outputs, in which case the signal is given both
for warning and for trip (thermal warning).
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.51.A1.02 - VLT is a registered Danfoss trade mark
118