1-90 Motor Thermal Protection
Option:
Function:
[8]
ETR trip 3
[9]
ETR warning
4
[10] ETR trip 4
[20] ATEX ETR
Activates the thermal monitoring function for
Ex-e motors for ATEX. Enables
,
and
[21] Advanced
ETR
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,
must be set to 150%.
3.3.10.1 PTC Thermistor Connection
1330
550
250
-20°C
175HA183.10
4000
3000
R
(Ω)
nominel
nominel -5°C
nominel +5°C
[°C]
Illustration 3.12 PTC Profile
Using a digital input and 10 V as power supply:
Example: The frequency converter trips when the motor
temperature is too high.
Parameter set-up:
Set
to
[2] Thermistor Trip
Set
to
[6] Digital Input
PTC / Thermistor
R
OFF
ON
<800 Ω
+10V
130BA152.10
>2.7 kΩ
12 13
18
37
32
27
19
29
33 20
55
50
39 42
53 54
Illustration 3.13
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
to
[2] Thermistor Trip
Set
to
[2] Analog Input 54
55
50
39 42
53 54
R
<3.0 k
Ω
>3.0 k
Ω
+10V
130BA153.11
PTC / Thermistor
OFF
ON
Illustration 3.14
Input
Digital/analog
Supply Voltage
Threshold
Cut-out Values
Digital
10 V
< 800
Ω
- > 2.7 k
Ω
Analog
10 V
< 3.0 k
Ω
- > 3.0 k
Ω
Table 3.7
NOTE
Check that the chosen supply voltage follows the specifi-
cation of the used thermistor element.
3.3.10.2 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 (
)
for PM motors and also rotor resistance (
) for asynchronous motors, depending on
winding temperature. The calculation is:
Rs = Rs20° C x (1 + αcu x ΔT) Ω
where
αcu = 0.00393
KTY sensors can be used for motor protecting (
).
Parameter Descriptions
VLT
®
AutomationDrive Programmming Guide
MG33ME02 - VLT
®
is a registered Danfoss trademark
47
3
3