Danfoss VLT AHF 005 Instruction Manual

Current limitations of the Flystart Principle used for PM
motors:
•
The speed range is up to 100% Nominal Speed or
the eld 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
veried 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 dierent ways:
•
Via a thermistor sensor connected
to one of the analog or digital
inputs (parameter 1-93 Thermistor
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
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. 89
6 6

Danfoss VLT AHF 005 Specifications

General

Brand	Danfoss
Model	VLT AHF 005
Category	DC Drives
Language	English