Safety Instructions And General Warning; Disposal Instruction; High Voltage Warning; Safety Instructions - Danfoss VLT AFE 302 Operating Instructions Manual

Safety Instructions and Gen...

2 Safety Instructions and General Warning

2 2

2.1.1 Disposal Instruction

2.1.2 High Voltage Warning

WARNING
The voltage of the AFE 302 is dangerous whenever the
frequency converter is connected to mains. Incorrect instal-
lation or operation of the frequency converter may cause
damage to the equipment, serious personal injury or death.
The instructions in this manual must consequently be
observed, as well as applicable local and national rules and
safety regulations.
WARNING
Installation in high altitudes
At altitudes above 2km, please contact Danfoss Drives
regarding PELV.

2.1.3 Safety Instructions

•
Make sure that the AFE 302 is properly connected
to earth.
•
Protect users against supply voltage.
•
Remember that the [OFF] key on LCP is not a safety
switch. Pressing the [OFF] key does not disconnect
the AFE 302 from the mains.

2.1.4 General Warnings

WARNING
Touching the electrical parts may be fatal even after the
equipment is disconnected from the mains.
Also make sure that the fan voltage supply is disconnected.
Check the discharge time on the nameplate for the exact
waiting period. Otherwise wait at least 40min.
6
VLT
Equipment containing electrical components
may not be disposed with domestic waste.
It must be separately collected with Electrical
and Electronic waste according to local and
currently valid legislation.
MG.33.X2.02 - VLT
®
Active Front End AFE 302 Operating Instructions Liebherr
NOTE
When the AFE is on, the earth current from the AFE 302
frequency converter will exceed 3.5mA. The earth cable must
have a good contact to the earth terminal 95. The earth
connection is done with the two separate cables. The size of
each cable needs to be a half of the mains cable size in
minimum.

2.1.5 Before Commencing Repair Work

1. Switch the complete system off.
2. Wait for discharge of the DC-link. See period of
time on the warning label.
3. Disconnect DC bus terminals 88 and 89.
4. Disconnect the soft charge supply connector from
the soft charge board.
CAUTION
MDCIC Mains Sync Connector (MK105) is supplying by
external 630V.
Switch off the main switch before you dismount the front
plate.

2.1.6 System Description

NOTE
The grounded Delta or IT mains will not be used.
In contrast to a passive diode rectifier front-end, an Active
Front End (AFE), sometimes called an Active Rectifier, is
designed with the IGBT-based inverrter. The topology of an
AFE is shown below. The AFE is comprised of the LCL filter
and the three-phase voltage source converter (IGBT with free
wheeling diodes).
The main purpose with the three-phase active rectifier is to
achieve:
•
sinusoidal input current and low harmonic
distortion in the mains
•
unity power factor
•
both rectifying and regenerating operation
•
constant regulated DC voltage
To operate properly, an AFE must continuously be
synchronized to the mains voltage and frequency. The
challenge is the start up sequence where the mains phase
must be sensed to achieve a smooth start of the AFE.
During normal operation, the DC-link voltage of the inverter
is regulated to a constant level independent of the power
®
is a registered Danfoss trademark