Danfoss VLT AQUA Drive FC 202 Programming Manual page 53

Parameter Description
1-87 Trip Speed Low [Hz]
Range: Function:
NOTICE
Size [ 0 -
related par.
*
This parameter is only available if
4-14
parameter 0-02 Motor Speed Unit is set
Hz]
to [Hz].
Enter the low limit for the motor speed at
which the frequency converter trips. If the
value is 0, the function is not active. If the
speed at any time after the start (or during a
stop) falls below the value in the parameter,
the frequency converter trips with the alarm
Speed Limit.
3.3.11 1-9* Motor Temperature
1-90 Motor Thermal Protection
Option: Function:
The frequency converter determines the
motor temperature for motor protection in 2
different ways:
•
Via a thermistor sensor connected
to one of the analog or digital
inputs (parameter 1-93 Thermistor
Source).
•
Via calculation (ETR = Electronic
Thermal Relay) of the thermal load,
based on the actual load and time.
The calculated thermal load is
comed with the rated motor current
I
M,N
f
M,N
need for a lower load at lower
speed due to less cooling from the
fan incorporated in the motor.
[0] No If the motor is continuously overloaded and
protection no warning or trip of frequency converter is
wanted.
[1] Thermistor Activates a warning when the connected
warning thermistor in the motor reacts in the event of
motor overtemperature.
[2] Thermistor Stops (trips) the frequency converter when
trip the connected thermistor in the motor reacts
in the event of motor overtemperature.
[3] ETR warning
1
[4] ETR trip 1
[5] ETR warning
2
[6] ETR trip 2
MG20O702
Programming Guide
and the rated motor frequency
. The calculations estimate the
Danfoss A/S © Rev. 2014-01-21 All rights reserved.
1-90 Motor Thermal Protection
Option: Function:
[7] ETR warning
3
[8] ETR trip 3
[9] ETR warning
4
[10] ETR trip 4
ETR (Electronic Thermal Relay) functions 1-4 calculate the
load when set-up where they were selected is active. For
example ETR-3 starts calculating when set-up 3 is selected.
For the North American market: The ETR functions provide
class 20 motor overload protection in accordance with
NEC.
t [s]
2000
1000
600
500
400
300
200
100
60
50
40
30
20
10
1.0 1.2 1.4 1.6 1.8
Illustration 3.12 Motor Overload Protection
WARNING
To maintain PELV, all connections made to the control
terminals must be PELV, e.g. thermistor must be
reinforced/double insulated
NOTICE
Danfoss recommends using 24 V DC as thermistor supply
voltage.
NOTICE
The ETR timer function does not work when
parameter 1-10 Motor Construction = [1] PM, non-salient
SPM.
NOTICE
For correct operation of ETR function setting in
1-03 Torque Characteristics must fit the application (see
description of 1-03 Torque Characteristics).
f OUT = 1 x f M,N (par. 1-23)
f OUT = 2 x f M,N
f OUT = 0. 2 x f M,N
I
M
I (par. 1-24)
2.0
MN
51
3 3