Danfoss VLT HVAC Basic Drive FC 101 Design Manual page 46

Product Overview
Using a digital input and 10 V as power supply:
2 2
Example: The adjustable frequency drive trips when the
motor temperature is too high.
Parameter set-up:
Set 1-90 Motor Thermal Protection to [2] Thermistor Trip
Set 1-93 Thermistor Source to [6] Digital Input 29
BUS TER.
OFF ON
61 68 69
0/4-20mA A OUT / DIG OUT
Figure 2.29 Digital Input/10 V Power Supply
Using an analog input and 10 V as power supply:
Example: The adjustable frequency drive trips when the
motor temperature is too high.
Parameter set-up:
Set 1-90 Motor Thermal Protection to [2] Thermistor Trip
Set 1-93 Thermistor Source to [2] Analog Input 54
NOTICE!
Do not set Analog Input 54 as reference source.
44
Design Guide
18 19 27 29 42 45 50 53 54
0/4-20mA A OUT / DIG OUT
12 20 55
OFF
ON
R
<800 Ω >2.9 kΩ
Danfoss A/S © Rev. 2014-01-14 All rights reserved.
BUS TER.
OFF
61 68 69
COM A IN
COM DIG IN
Figure 2.30 Analog Input/10 V Power Supply
Input
Digital
Analog
Table 2.25 Supply Voltage
NOTICE!
Check that the selected supply voltage follows the
specification of the used thermistor element.
Summary
With the ETR, the motor is protected for being overheated
and there is no need for any further motor protection.
That means when the motor is heated up, the ETR timer
controls for how long time the motor can run at the high
temperature before it is stopped to prevent over heating.
If the motor is overloaded without reaching the
temperature, the ETR shuts of the motor.
ETR is activated in 1-90 Motor Thermal Protection.
ON
18 19 27 29 42 45 50 53 54
0/4-20mA A OUT / DIG OUT 0/4-20mA A OUT / DIG OUT
12 20 55
OFF
ON
<3.0 k Ω
>2.9k Ω
Supply Voltage Threshold
[V]
Cut-out Values [Ω]
<800 ⇒ 2.9 k
10
<800 ⇒ 2.9 k
10
COM A IN
COM DIG IN
R
MG18C522