PDL D3-2.5, Instruction Manual, Page: 86 / 113

Microdrive Series Instruction Manual
4201-109 Rev I
86
FREE WHEELING
HV LOW TRIP=N; T>2s
HV LOW TRIP=Y; T 2s
POWER LOSS RIDE THROUGH
POWER LOSS
Hz Hz
RPM
V V
V V
4807−079 Rev D
SPINNING START
POWER RECOVERY
OUTPUT FREQUENCY
LOAD SPEED
MAINS POWER
CONTROL POWER
<_
73
73 MAINS POWER LOSS RESPONSE
Screen 73 HV LOW TRIP=N
Description MAINS POWER LOSS RESPONSE
Options [Y]ES/[N]O
FUNCTION The high voltage (mains supply) power loss
function provides an optional response to a
power loss situation.
Upon power loss or brown out conditions, the
Microdrive continues to operate normally until
the energy supplied to the motor load discharges
the Microdrive high voltage DC bus to 400Vdc.
At this stage the output power from the
Microdrive is disabled to prevent further energy
consumption by the load, but otherwise the
Microdrive continues to operate from the
remaining energy in the DC bus. Depending on
the size of the Microdrive (and hence the
energy in its DC bus), the Microdrive can stay
active for several seconds in such an event.
While in this state (before the DC bus
discharges below the switch mode power
supply (SMPS) operating voltage – about
200Vdc in the UD3, 350Vdc in the UDi) and
depending upon the setting mode of this screen,
the Microdrive is able to restart and continue
normal operation when the mains supply
returns to normal.
If the high voltage (mains supply) power loss
function is set to trip (Y), the Microdrive will
trip, register a mains low fault after a two
second power loss and require resetting. If
the mains returns to normal within two
seconds, the Microdrive will restart
automatically and perform a spinning start at
the set frequency.
If the high voltage (mains supply) power loss
function is set to not trip (N), the Microdrive will
stay active as long as there is sufficient DC
supply (perhaps several seconds). If the
mains returns to normal while the Microdrive
is still active, the Microdrive will restart
automatically at the current set frequency.
SETTING UP The decision of whether to trip or not is usually
based upon questions of the safety of
automatically restarting equipment after brief
power outages, of the ability of associated
equipment to continue normal operation and of
the reliability required of a process.
You must assess these factors to make your
decision.