4.2.10.2 KTY Sensor Connection
KTY sensors are used especially in permanent magnet servo motors (PM motors) for dynamic adjusting of motor parameters as sta-
tor resistance (
parameter 1-30 Stator Resistance (Rs)
) for PM motors and also rotor resistance (
parameter 1-31 Rotor Resistance (Rr)
) for
asynchronous motors, depending on winding temperature. The calculation is:
Rs = Rs
20° C
x (1 + α
cu
x ΔT) Ω where α
cu
= 0 . 00393
KTY sensors can be used for motor protecting (
parameter 1-97 KTY Threshold level
). can handle 3 types of KTY sensors, defined in
parameter 1-95 KTY Sensor Type
. The actual sensor temperature can be read out from
parameter 16-19 KTY sensor temperature
.
0
500
1000
1500
2000
2500
3000
3500
4000
4500
-25
0
25
50
75
100
125
150
Temperature [°C]
R
e
si
st
a
n
c
e
[O
h
m
]
KTY type 1
KTY type 2
KTY type 3
e
3
0
b
b
9
1
7
.1
1
Illustration 37: KTY Type Selection
KTY Sensor 1: 1 kΩ at 100 °C (212 °F) (for example Philips KTY 84-1)
KTY Sensor 2: 1 kΩ at 25 °C (77 °F) (for example Philips KTY 83-1)
KTY Sensor 3: 2 kΩ at 25 °C (77 °F) (for example Infineon KTY-10)
N O T I C E
If the temperature of the motor is utilized through a thermistor or KTY sensor, the PELV is not complied with if there are short
circuits between motor windings and the sensor. Put extra isolation on the sensor to comply with PELV.
4.2.10.3 ETR
The calculations estimate the need for a lower load at lower speed due to less cooling from the fan incorporated in the motor.
AU373327181955en-000101 / 130R1208
94 | Danfoss A/S © 2021.08
Parameter Descriptions
VLT® AutomationDrive EZ FC 321
Programming Guide
