Danfoss VLT AHF 005 Design Guide

drive is shown as the default value in
parameter 14-01 Switching Frequency.
Compatibility of motor and drive
For motors certied according to EN-60079-7, a data list
including limits and rules is supplied by the motor
manufacturer as a datasheet, or on the motor nameplate.
During planning, installation, commissioning, operation,
and service, follow the limits and rules supplied by the
manufacturer for:
•
Minimum switching frequency.
•
Maximum current.
•
Minimum motor frequency.
•
Maximum motor frequency.
Illustration 5.2 shows where the requirements are indicated
on the motor nameplate.
130BD888.10
CONVERTER SUPPLY
VALID FOR 380 - 415V FWP 50Hz
3 ~ Motor
MIN. SWITCHING FREQ. FOR PWM CONV. 3kHz
l = 1.5XI
M,N
tOL = 10s tCOOL = 10min
MIN. FREQ. 5Hz MAX. FREQ. 85 Hz
PWM-CONTROL
f [Hz]
Ix/I
M,N
PTC °C DIN 44081/-82
Manufacture xx
EN 60079-0
EN 60079-7
СЄ 1180 Ex-e ll T3
5 15 25 50 85
0.4 0.8 1.0 1.0 0.95
1
xЗ
2
3
4
1 Minimum switching frequency
2 Maximum current
3 Minimum motor frequency
4 Maximum motor frequency
Illustration 5.2 Motor Nameplate showing Drive Requirements
When matching drive and motor, Danfoss species the
following extra requirements to ensure adequate motor
thermal protection:
•
Do not exceed the maximum allowed ratio
between drive size and motor size. The typical
value is I
VLT, n
≤2xI
m,n
•
Consider all voltage drops from drive to motor. If
the motor runs with lower voltage than listed in
the U/f characteristics, current can increase,
triggering an alarm.
For further information, see the application example in
chapter 12 Application Examples.
5.2.5 Mains Drop-out
During a mains drop-out, the drive keeps running until the
DC-link voltage drops below the minimum stop level. The
minimum stop level is typically 15% below the lowest
rated supply voltage. The mains voltage before the drop-
out and the motor load determines how long it takes for
the drive to coast.
The drive can be
congured (parameter 14-10 Mains Failure)
to dierent types of behavior during mains drop-out:
•
Trip lock once the DC link is exhausted.
•
Coast with ying start whenever mains return
(parameter 1-73 Flying Start).
•
Kinetic back-up.
•
Controlled ramp down.
Flying start
This selection makes it possible to catch a motor that is
spinning freely due to a mains drop-out. This option is
relevant for centrifuges and fans.
Kinetic back-up
This selection ensures that the drive runs as long as there
is energy in the system. For short mains drop-out, the
operation is restored after mains return, without bringing
the application to a stop or losing control at any time.
Several variants of kinetic back-up can be selected.
Congure the behavior of the drive at mains drop-out, in
parameter 14-10 Mains Failure and parameter 1-73 Flying
Start.
5.2.6 Automatic Restart
The drive can be programmed to restart the motor
automatically after a minor trip, such as momentary power
loss or uctuation. This feature eliminates the need for
manual resetting, and enhances automated operation for
remotely controlled systems. The number of restart
attempts and the duration between attempts can be
limited.
5.2.7 Full Torque at Reduced Speed
The drive follows a variable V/Hz curve to provide full
motor torque even at reduced speeds. Full output torque
can coincide with the maximum designed operating speed
of the motor. This drive diers from variable torque drives
and constant torque drives. Variable torque drives provide
reduced motor torque at low speed. Constant torque
drives provide excess voltage, heat, and motor noise at less
than full speed.
Product Features
VLT
®
HVAC Drive FC 102
24 Danfoss A/S © 11/2017 All rights reserved. MG16C302
55

Danfoss VLT AHF 005 Specifications

General

Brand	Danfoss
Model	VLT AHF 005
Category	DC Drives
Language	English