bonitron M3345, Reference Manual

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User’s Manual
17
4. O
PERATION
4.1.
F
UNCTIONAL
D
ESCRIPTION
The M3345 Line Regen enables energy being generated by an over-hauling motor to
be efficiently returned to the power grid. Alternative solutions typically consist of
dissipating the returned energy in a resistor or simply allowing the motor to coast
uncontrolled to a stop.
The M3345 Line Regen establishes a reference from the power source connected to
the 3 phase input. This reference is used to establish the actual rectified DC voltage
which is equal to the DC bus of the AC Drive in standby. The DC reference allows
for conduction back to the AC line with limited rise in DC bus voltage. The reference
is also used to monitor instantaneous changes in the incoming voltage.
Instantaneous changes in voltage greater than 15% can create an over-power
condition for the power semiconductors. The M3345 will go into a shutdown mode
during such events and resume operation upon return of nominal voltage. The
M3345 will also go into the shutdown mode upon loss of any phase of the incoming
power.
The M3345 series of Regen Modules come standard with an internal bus structure
which allows for regeneration from the drive to the AC Line only. Power may be
transferred from the AC drive to the regen; however, the regen will not provide
energy to the AC drive.
4.2.
F
EATURES
•
Fusing
•
Internal line filtering
•
Current metering
•
Power indicator
•
Status contact
•
I/O for paralleling 60, 90, and 120 Amp units
4.2.1.
F
USING
The M3345 Line Regen is provided with fusing for the AC input and the DC
bus input. All fuses are fast semiconductor type and should only be
replaced with original type. Please refer to Table 6-4 in Section 6.4.
4.2.2.
I
NTERNAL
L
INE
F
ILTERING
The M3345 series Line Regen incorporates internal filtering on the AC line
to remove voltage transients created by the internal transistors. It also adds
additional filtering to noise and harmonics that may be generated outside of
the regen. The internal filtering is not intended for filtering external
harmonics and if there are any known power quality issues extra attention
should be given when startups are performed.