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2.1.5 Special Conditions
Electrical ratings:
The rating indicated on the nameplate of the frequency converter is
based on a typical 3-phase mains power supply, within the specified
voltage, current and temperature range, which is expected to be used
in most applications.
The frequency converters also support other special applications, which
affect the electrical ratings of the frequency converter.
Special conditions which affect the electrical ratings might be:
•
Single phase applications
•
High temperature applications which require de-rating of the
electrical ratings
•
Marine applications with more severe environmental condi-
tions.
Other applications might also affect the electrical ratings.
Consult the relevant sections in this manual and in the
VLT HVAC Drive
Design Guide, MG.11.BX.YY
for information about the electrical ratings.
Installation requirements:
The overall electrical safety of the frequency converter requires special
installation considerations regarding:
•
Fuses and circuit breakers for over-current and short-circuit
protection
•
Selection of power cables (mains, motor, brake, loadsharing
and relay)
•
Grid configuration (grounded delta transformer leg, IT,TN,
etc.)
•
Safety of low-voltage ports (PELV conditions)
Consult the relevant clauses in these instructions and in the VLT HVAC
Drive Design Guide for information about the installation requirements.
2.1.6 Installation at High Altitudes (PELV)
Installation at high altitude:
380 - 480 V: At altitudes above 3 km, please contact
Danfoss regarding PELV.
525 - 690 V: At altitudes above 2 km, please contact
Danfoss regarding PELV.
2.1.7 Avoid Unintended Start
While the frequency converter is connected to mains,
the motor can be started/stopped using digital com-
mands, bus commands, references or via the Local
Control Panel.
•
Disconnect the frequency converter from
mains whenever personal safety considera-
tions make it necessary to avoid unintended
start.
•
To avoid unintended start, always activate
the [OFF] key before changing parameters.
•
Unless terminal 37 is turned off, an elec-
tronic fault, temporary overload, a fault in
the mains supply, or lost motor connection
may cause a stopped motor to start.
VLT HVAC Drive High Power Operating In-
structions
2 Safety
MG.11.F3.02 - VLT
®
is a registered Danfoss trademark
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