Current limitations of the Flystart Principle used for PM
motors:
•
The speed range is up to 100% Nominal Speed or
the field weakening speed (which ever is lowest).
•
PMSM with high back emf (>300 VLL(rms)) and
high winding inductance(>10 mH) needed more
time for reducing short circuit current to zero and
may be susceptible to error in estimation.
•
Current testing limited to a speed range up to
300 Hz. For certain units, the limit is 250 Hz; all
200
‒
240V units up to and including 3 HP [2.2
kW] and all 380
‒
480V units up to and including
5.4 HP [4 kW].
•
Current testing limited to a machine power size
up to 30 HP [22 kW].
•
Prepared for salient pole machine (IPMSM) but
not yet verified on those types of machine.
•
For high inertia applications (i.e., where the load
inertia is more than 30 times larger than the
motor inertia), a brake resistor is recommended
to avoid overvoltage trip during high speed
engagement of the Flystart function.
1-80 Function at Stop
Option:
Function:
Select the adjustable frequency drive function
after a stop command or after the speed is
ramped down to the settings in
parameter 1-81 Min Speed for Function at Stop
[RPM]
.
Available selections depend on
parameter 1-10 Motor Construction
:
[0] Asynchron:
[0] coast
[1] DC hold
[2] Motor check, warning
[6] Motor check, alarm
[1] PM non-salient:
[0] coast
[0]
*
Coast
Leaves motor in free mode.
[1]
DC Hold/
Motor
Preheat
Energizes motor with a DC holding current (see
parameter 2-00 DC Hold/Preheat Current
).
[2]
Motor
check,
warn.
Issues a warning if the motor is not connected.
[6]
Motor
check,
alarm
Issues an alarm if the motor is not connected.
1-90 Motor Thermal Protection
Option:
Function:
The adjustable frequency drive determines
the motor temperature for motor protection
in two different ways:
•
Via a thermistor sensor connected
to one of the analog or digital
inputs (
•
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 overtemperature.
[2]
Thermistor
trip
Stops (trips) the adjustable frequency drive
when the connected thermistor in the motor
reacts in the event of motor overtem-
perature.
[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.
How to Program
Instruction Manual
MG11F522
Danfoss A/S © 08/2014 All rights reserved.
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Содержание VLT HVAC Drive FC 102
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