1-90 Motor Thermal Protection
Option:
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
•
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
M,N
and the rated motor frequency f
M,N
. The calculations estimate the need for a lower
load at lower speed due to less cooling from the fan incorporated in the motor.
[0]
No protection
If the motor is continuously overloaded and no warning or trip of adjustable frequency drive is
wanted.
[1]
Thermistor warning
Activates a warning when the connected thermistor in the motor reacts in the event of motor over-
temperature.
[2]
Thermistor trip
Stops (trips) the adjustable frequency drive when the connected thermistor in the motor reacts in
the event of motor overtemperature.
[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.
6 How to program the adjustable frequency
drive
VLT
®
HVAC Drive Instruction Manual
6-24
MG.11.A9.22 - VLT
®
is a registered Danfoss trademark
6
Содержание VLT
Страница 8: ...1 Safety VLT HVAC Drive Instruction Manual 1 6 MG 11 A9 22 VLT is a registered Danfoss trademark 1...
Страница 152: ...7 Troubleshooting VLT HVAC Drive Instruction Manual 7 8 MG 11 A9 22 VLT is a registered Danfoss trademark 7...
Страница 174: ...8 Specifications VLT HVAC Drive Instruction Manual 8 22 MG 11 A9 22 VLT is a registered Danfoss trademark 8...