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3 Parameter Description
3.3.9 1-9* Motor Temperature
Parameters for setting the temperature protection features for the motor.
1-90 Motor Thermal Protection
Option:
3
[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
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.
3-28
Function:
The adjustable frequency drive determines the motor temperature for motor protection in two dif-
ferent ways:
•
Via a thermistor sensor connected to one of the analog or digital inputs (par.1-93
mistor Source
).
•
Via calculation (ETR = Electronic Thermal Relay) of the thermal load, based on the actual
load and time. The calculated thermal load is compared with the rated motor current
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.
MG.11.C6.22 - VLT
®
is a registered Danfoss trademark
VLT
®
HVAC Drive Programming Guide
. The calculations estimate the need for a lower
M,N
Ther-
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