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6.1.17 Sleep Mode
Sleep mode automatically stops the motor when demand is low for a specified period. When the system demand increases, the
drive restarts the motor. Sleep mode provides energy savings and reduces motor wear. Unlike a setback clock, the drive is always
available to run when the preset wake-up demand is reached.
6.1.18 Run Permissive
The drive can wait for a remote
system ready
signal before starting. When this feature is active, the drive remains stopped until re-
ceiving permission to start. Run permissive ensures that the system or auxiliary equipment is in the proper state before the drive is
allowed to start the motor.
6.2 Custom Application Features
Custom application functions are the most common features programmed in the drive for enhanced system performance. They re-
quire minimum programming or set-up. See the programming guide for instructions on activating these functions.
6.2.1 Automatic Motor Adaptation (AMA)
Automatic motor adaptation (AMA) is an automated test procedure used to measure the electrical characteristics of the motor. AMA
provides an accurate electronic model of the motor, allowing the drive to calculate optimal performance and efficiency. Running the
AMA procedure also maximizes the automatic energy optimization feature of the drive. AMA is performed without the motor rotat-
ing and without uncoupling the load from the motor.
6.2.2 Motor Thermal Protection
Motor thermal protection can be provided via:
Direct temperature sensing using a
PTC- or KTY sensor in the motor windings and connected on a standard AI or DI.
PT100 or PT1000 in the motor windings and motor bearings, connected on VLT® Sensor Input Card MCB 114 and VLT® Pro-
grammable I/O MCB 115.
PTC thermistor input on VLT® PTC Thermistor Card MCB 112 (ATEX-approved).
Mechanical thermal switch (Klixon type) on a DI.
Built-in electronic relay (ETR).
ETR calculates motor temperature by measuring current, frequency, and operating time. The drive shows the thermal load on the
motor in percentage and can issue a warning at a programmable overload setpoint. Programmable options at the overload allow
the drive to stop the motor, reduce output, or ignore the condition. Even at low speeds, the drive meets I2t Class 20 electronic motor
overload standards.
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]
e7
5z
a0
52
.1
3
I
M,N
(parameter 1-24)
I
M
f
OUT
= 2 x f
M,N
(parameter 1-23)
f
OUT
= 1 x f
M,N
f
OUT
= 0.2 x f
M,N
Illustration 31: ETR Characteristics
The X-axis shows the ratio between I
motor
and I
motor
nominal. The Y-axis shows the time in seconds before the ETR cuts off and trips
the drive. The curves show the characteristic nominal speed at twice the nominal speed and at 0.2 x the nominal speed. At lower
speed, the ETR cuts off at lower heat due to less cooling of the motor. In that way, the motor is protected from being overheated
even at low speed. The ETR feature calculates the motor temperature based on actual current and speed. The calculated tempera-
ture is visible as a readout parameter in
parameter 16-18 Motor Thermal
. A special version of the ETR is also available for EX-e or EX-n
AJ300847815559en-000101 / 130R0337 | 45
Danfoss A/S © 2020.09
Product Features
VLT® AQUA Drive FC 202
Design Guide