6.7 Running in Reduced Power Mode
If a drive module fails, this function allows the drive system
to run in reduced power mode until the failed drive
module is replaced. In accordance with the reduced
capability, the protection limits and working limits are
scaled down.
Before configuring the drive for reduced power mode, read
and understand the following safety guidelines.
6.7.1 Safety
Only qualified personnel should install and service the
VLT
®
Parallel Drive Modules.
Qualified personnel are defined as trained staff, who are
authorized to install equipment, systems, and circuits in
accordance with pertinent laws and regulations. Also, the
personnel must be familiar with the instructions and safety
measures described in this manual.
WARNING
HIGH VOLTAGE
The drive system contains high voltage when connected
to AC mains input, DC supply, or load sharing. Failure to
perform installation, startup, and maintenance by
qualified personnel can result in death or serious injury.
•
Only qualified personnel must perform instal-
lation, startup, and maintenance.
WARNING
UNINTENDED MOTOR ROTATION
WINDMILLING
Unintended rotation of permanent magnet motors
creates voltage and can charge the capacitors in the
drive system, resulting in death, serious injury, or
equipment damage.
•
Ensure that permanent magnet motors are
blocked to prevent unintended rotation.
WARNING
DISCHARGE TIME
The drive module contains DC-link capacitors. Once
mains power has been applied to the drive, these
capacitors can remain charged even after the power has
been removed. High voltage can be present even when
the warning indicator lights are off. Failure to wait 20
minutes after power has been removed before
performing service or repair work can result in death or
serious injury.
•
Stop the motor.
•
Disconnect AC mains and remote DC-link
supplies, including battery back-ups, UPS, and
DC-link connections to other drives.
•
Disconnect or lock the PM motor.
•
Wait 20 minutes for the capacitors to discharge
fully before performing any service or repair
work.
WARNING
EQUIPMENT HAZARD
Contact with rotating shafts and electrical equipment
can result in death or serious injury.
•
Ensure that only trained and qualified personnel
perform the installation.
•
Ensure that electrical work conforms to national
and local electrical codes.
•
Follow the procedures in this manual.
WARNING
DISCONNECT POWER BEFORE SERVICING
Sometimes during installation, AC mains power is
applied but then must be disconnected to change the
line connections. Failure to follow these steps can result
in death or serious injury.
•
Disconnect the frequency converters from the
AC mains, 230 V supply, and motor lines.
•
After the lines have been disconnected, wait 20
minutes for the capacitors to discharge.
Maintenance, Diagnostics, a...
User Guide
MG37L202
Danfoss A/S © 08/2017 All rights reserved.
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