Danfoss VLT HVAC Drive FC 102, Руководство по программированию, Страница: 53 / 250

3.3.12 1-9* Motor Temperature
NOTICE
When using multiple motors, VLT
®
HVAC Drive FC 102
electronic thermal relay cannot be used to provide
individual motor protection. Supply a separate motor
overload for each motor.
1-90 Motor Thermal Protection
Option: Function:
The frequency converter determines the
motor temperature for motor overload
protection in 2 different ways:
•
Via a thermistor sensor connected
to 1 of the analog or digital inputs
(
parameter 1-93 Thermistor Source ).
See chapter 3.3.13.1 PTC Thermistor
Connection .
•
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. See
chapter 3.3.13.2 ETR .
•
Via a mechanical thermal switch
(Klixon type). See
chapter 3.3.13.3 Klixon . The ETR
provides class 20 motor overload
protection in accordance with NEC.
[0] No
protection If the motor is continuously overloaded, and
no warning or trip of frequency converter is
wanted.
[1] Thermistor
warning Activates a warning when the connected
thermistor in the motor reacts in the event of
motor overtemperature.
[2] Thermistor
trip Stops (trips) the frequency converter 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
1-90 Motor Thermal Protection
Option: Function:
[9] ETR warning
4
[10] ETR trip 4
ETR functions 1-4 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.
1.2 1.0 1.4
30
10
20
100
60
40
50
1.8 1.6 2.0
2000
500
200
400
300
1000
600
t [s]
175ZA052.12
fOUT = 2 x f M,N
fOUT = 0.2 x f M,N
fOUT = 1 x f M,N(par. 1-23)
I
MN
(par. 1-24)
I
M
Illustration 3.10 Thermal Motor Protection
NOTICE
If the temperature of the motor is monitored through a
thermistor or a KTY Sensor, the PELV is not complied
with in case of short circuits between motor windings
and the sensor. To comply with PELV, the sensor must be
isolated appropriately.
NOTICE
Danfoss recommends using 24 V DC as thermistor supply
voltage.
NOTICE
The ETR timer function does not work when
parameter 1-10 Motor Construction = [1] PM, non-salient
SPM .
NOTICE
For correct operation of the ETR function, the setting in
parameter 1-03 Torque Characteristics must fit the
application (see description of parameter 1-03 Torque
Characteristics ).
Parameter Descriptions Programming Guide
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