Operating instructions

Enhanced safety built-in
Speed
Diff erential pressure
Easy to open doors
Fresh air in
Mains switch option
This switch interrupts the mains
supply and has a free useable auxiliary
contact. The mains switch ensures the
safety of staff during maintenance and
cleaning operations.
The mains switch option also reduces
assembly cost.
Fire Override Mode
Activating the function “Fire-mode”
within the VLT® drive ensures secure
and continued operation within
applications such as stair-well
pressurization, car park exhaust fans,
smoke exhaust and essential service
functions.
Clearly indicated
Fire mode is clearly indicated on the
VLT® display to prevent any confusion.
When set, the drive will override self
protection and will continue
operation despite the possibility of
permanent damage in case of over-
heating or overload. The vital goal is
to keep the motor running even if it
means self-destruction.
Drive bypass
If a drive bypass is available, the VLT®
HVAC Drive will not only sacrifi ce itself
in case of an extreme condition, but is
able to bypass itself and connect the
motor directly to mains. This will
maintain operation as long as power is
provided and the motor is
functioning.
Safe Stop
The VLT® HVAC Drive comes standard
with the safe stop functionality. The
solution is approved by authorities for
category 3 installations in accordance
with EN 954-1. This feature prevents
the drive from starting unintended.
Thermistor card
With the PTC Thermistor Card MCB
112 the Danfoss VLT® HVAC Drive
off ers improved surveillance of the
motor condition compared to the
built-in ETR function and thermistor
terminal.
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