Kty Sensor Connection; Etr - Danfoss VLT AutomationDrive FC 300 Operating Instructions Manual

How to Programme the Low Ha...
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
Set 1-90 Motor Thermal Protection to Thermistor Trip [2]
Set 1-93 Thermistor Source to Digital Input [6]
39 42 50 53 54 55
12 13 18 19 27 29 32 33 20 37
PTC / Thermistor
Illustration 6.3
Using an analog input and 10 V as power supply:
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
Set 1-90 Motor Thermal Protection to Thermistor Trip [2]
Set 1-93 Thermistor Source to Analog Input 54 [2]
39 42 50 53 54 55
PTC / Thermistor
Illustration 6.4
Input Supply Voltage
Digital/analog
Digital 10 V
Analog 10 V
Table 6.2
NOTE
Check that the chosen supply voltage follows the specifi-
cation of the used thermistor element.

6.1.3.2 KTY Sensor Connection

(FC 302 only)
KTY sensors are used especially in Permanent Magnet
Servo Motors (PM motors) for dynamic adjusting of motor
parameters as stator resistance (1-30 Stator Resistance (Rs))
for PM motors and also rotor resistance (1-31 Rotor
VLT Automation Low Harmonic Drive Operating Instructions
OFF
ON
R
<800 Ω >2.7 kΩ
OFF
ON
<3.0 k Ω
R
>3.0 k Ω
Threshold
Cut-out Values
< 800 Ω - > 2.7 kΩ
< 3.0 kΩ - > 3.0 kΩ
®
MG34O202 - VLT is a registered Danfoss trademark
Resistance (Rr)) for asynchronous motors, depending on
winding temperature. The calculation is:
where
Rs = Rs 20° C x (1 + α cu x Δ T ) Ω
KTY sensors can be used for motor protecting (1-97 KTY
Threshold level).
FC 302 can handle three types of KTY sensors, defined in
1-95 KTY Sensor Type. The actual sensor temperature can be
read out from 16-19 KTY sensor temperature.
4500
4000
3500
3000
2500
2000
1500
1000
500
0
-25 0 25 50
Temperature [°C]
KTY type 1
Illustration 6.5 KTY type selection
KTY Sensor 1: KTY 84-1 with 1 kΩ at 100° C
KTY Sensor 2: KTY 81-1, KTY 82-1 with 1 kΩ at 25° C
KTY Sensor 3: KTY 81-2, KTY 82-2 with 2 kΩ at 25° C
NOTE
If the temperature of the motor is utilized through a
thermistor or KTY sensor the PELV is not complied with in
case of short circuits between motor windings and sensor.
In order to comply with PELV the sensor must be extra
isolated.

6.1.3.3 ETR

The calculations estimate the need for a lower load at
lower speed due to less cooling from the fan incorporated
in the motor.
α cu = 0.00393
75 100 125 150
KTY type 2 KTY type 3
71
6 6