Danfoss VLT FC 102 Programming Manual page 70

Parameter Descriptions
39 42 50 53 54 55
3 3
PTC / Thermistor
Illustration 3.13 PTC Thermistor Connection - Analog Input
Input
digital/analog
Digital
Analog
Table 3.9 Threshold Cutout Values
NOTICE
Check that the selected supply voltage follows the
specification of the used thermistor element.
3.3.13.2 ETR
The calculations estimate the need for a lower load at
lower speed due to less cooling from the fan incorporated
in the motor.
t [s]
2000
1000
600
500
400
300
200
100
60
50
40
30
20
10
1.0
Illustration 3.14 ETR Profile
3.3.13.3 Klixon
The Klixon type thermal circuit breaker uses a KLIXON
metal dish. At a predetermined overload, the heat caused
by the current through the disc causes a trip.
Example using a digital input and 24 V as supply
The frequency converter trips when the motor temperature
is too high.
Parameter set-up:
68
OFF
ON
<3.0 k Ω
>3.0 k
Supply voltage Threshold
[V] cutout values.
<800 Ω⇒2.7 kΩ
10
10 <3.0 kΩ⇒3.0 kΩ
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
1.2 1.4 1.6 1.8 2.0
Danfoss A/S © 10/2019 All rights reserved.
®
VLT HVAC Drive FC 102
•
•
12 13 18
R
Ω
PTC / Thermistor
Illustration 3.15 Thermistor Connection
1-91 Motor External Fan
Option:
[0]
*
[1]
1-93 Thermistor Source
Option:
I
M
(par. 1-24)
MN
®
Set parameter 1-90 Motor Thermal Protection to [2]
Thermistor Trip.
Set parameter 1-93 Thermistor Source to [6] Digital
Input.
OFF
19 27 29 32 33 20 37
ON
<6.6 k Ω >10.8 k Ω
Function:
No No external fan is required, that is,
the motor is derated at low speed.
Yes Applies an external motor fan
(external ventilation), so no
derating of the motor is required at
low speed. The upper curve in
Illustration 3.14 (f
followed if the motor current is
lower than nominal motor current
(see parameter 1-24 Motor Current).
If the motor current exceeds
nominal current, the operation time
still decreases as if no fan was
installed.
Function:
NOTICE
This parameter cannot be
adjusted while the motor is
running.
NOTICE
Set digital input to [0] PNP -
Active at 24 V in
parameter 5-00 Digital I/O
Mode.
Select the input to which the
thermistor (PTC sensor) should be
connected. An analog input option
[1] Analog Input 53 or [2] Analog
Input 54 cannot be selected if the
analog input is already in use as a
reference source (selected in
parameter 3-15 Reference 1 Source,
parameter 3-16 Reference 2 Source,
R
= 1 x f ) is
out M,N
M0010001