Thermistor Source - Danfoss VLT HVACDrive Instruction Manual

7 How to Program the Adjustable Frequency
Drive
[0] No protection
[1] Thermistor warning
[2] Thermistor trip
[3] ETR warning 1
[4] * ETR trip 1
[5] ETR warning 2
[6] ETR trip 2
[7] ETR warning 3
[8] ETR trip 3
[9] ETR warning 4
[10] ETR trip 4
7
ETR (Electronic Thermal Relay) functions 1-4 will calculate the load when the set-up where they were selected is active. For example, ETR-3 starts
calculating when Set-up 3 is selected. For the North American market: The ETR functions provide class 20 motor overload protection in accordance with
NEC.
NOTE!
Danfoss recommends using 24 VDC as thermistor supply voltage.

1-93 Thermistor Source

Option:
7-18
I and the rated motor frequency f
M,N
load at lower speed due to less cooling from the fan incorporated in the motor.
If the motor is continuously overloaded and no warning or trip of adjustable frequency drive is
wanted.
Activates a warning when the connected thermistor in the motor reacts in the event of motor over-
temperature.
Stops (trips) the adjustable frequency drive when the connected thermistor in the motor reacts in
the event of motor overtemperature.
Function:
Select the input to which the thermistor (PTC sensor) should be connected. An analog input option
[1] or [2] cannot be selected if the analog input is already in use as a reference source (selected in
par. 3-15 Reference 1 Source , par. 3-16
When using MCB112, choice [0] None
MG.11.AB.22 - VLT ® is a registered Danfoss trademark
VLT ® HVAC Drive Instruction Manual
. The calculations estimate the need for a lower
M,N
Reference 2 Source or par. 3-17 Reference 3 Source
must always be selected.
).