Ptc Thermistor Connection - Danfoss VLT AutomationDrive FC 300 Operating Instructions Manual

How to Programme the Low Ha...
1-04 Overload Mode
Option:
[0] High torque
*
[1] Normal torque For oversized motor - allows up to 110%
NOTE
This parameter cannot be adjusted while the motor is
running.
1-90 Motor Thermal Protection
Option:
6 6
[0] No
*
protection
[1] Thermistor
warning
[2] Thermistor
trip
[3] ETR warning
1
70
VLT Automation Low Harmonic Drive Operating Instructions
Function:
Allows up to 160% over torque.
over torque.
Function:
Thermal motor protection can be
implemented using a range of techniques:
•
Via a PTC sensor in the motor
windings connected to one of the
analog or digital inputs
(1-93 Thermistor Source). See

6.1.3.1 PTC Thermistor Connection.

•
Via a KTY sensor in the motor
winding connected to an analog
input (1-96 KTY Thermistor Resource).
See 6.1.3.2 KTY Sensor Connection.
•
Via calculation (ETR = Electronic
Thermal Relay) of the thermal load,
based on the actual load and time.
The calculated thermal load is
compared with the rated motor
current I and the rated motor
M,N
frequency f . See 6.1.3.3 ETR and .
M,N
•
Via a mechanical thermal switch
(Klixon type). See 6.1.3.4 ATEX ETR.
For the North American market: The ETR
functions provide class 20 motor overload
protection in accordance with NEC.
Continuously overloaded motor, when no
warning or trip of the frequency converter is
required.
Activates a warning when the connected
thermistor or KTY-sensor in the motor reacts
in the event of motor over-temperature.
Stops (trips) frequency converter when
connected thermistor or KTY sensor in the
motor reacts in the event of motor over-
temperature.
The thermistor cut-out value must be > 3
kΩ.
Integrate a thermistor (PTC sensor) in the
motor for winding protection.
Calculates the load when set-up 1 is active
and activates a warning on the display when
MG34O202 - VLT
1-90 Motor Thermal Protection
Option:
[4] ETR trip 1
[5] ETR warning
2
[6] ETR trip 2
[7] ETR warning
3
[8] ETR trip 3
[9] ETR warning
4
[10] ETR trip 4
NOTE
If [20] is selected, follow strictly the instructions described
in the dedicated chapter of the VLT AutomationDrive
design guide and the instructions given by the motor
manufacturer.
NOTE
If [20] is selected, 4-18 Current Limit must be set to 150%.
6.1.3.1 PTC Thermistor Connection
R
(Ω)
4000
3000
1330
550
250
-20°C
Illustration 6.2 PTC profile
Using a digital input and 10 V as power supply:
®
is a registered Danfoss trademark
Function:
the motor is overloaded. Programme a
warning signal via one of the digital outputs.
Calculates the load when set-up 1 is active
and stops (trips) frequency converter when
the motor is overloaded. Programme a
warning signal via one of the digital outputs.
The signal appears in the event of a warning
and if the frequency converter trips (thermal
warning).
 nominel -5°C
 nominel +5°C
 nominel
 [°C]