BENSHAW M2L 3000, User Manual

Page: 135 / 140

Glossary
135
Isolating CT
An Isolating CT is a toroid-shaped current transformer mounted on an insulating cyl-
inder. The insulating cylinder has a hole in its center that retains the primary current-
carrying conductor. The Inverter has Isolating CTs on the back of its Power Cell
Back Panels for each Power Cell. The Converter has two Isolating CTs mounted
above its Low Voltage Box. The Isolating CTs provide a means of transferring power
from the primary, current-carrying conductor to a load attached to its secondary side,
while maintaining Medium Voltage isolation between the primary and secondary
sides of the transformer.
Loop Power Supply Reac-
tor
The Loop Power Supply Reactor is a Single-Pole Line Reactor. The Inverter has a
Loop Power Supply Reactor on the Top Back Panel of its Input Section. The Loop
Power Supply Reactor limits the current through the loop of wire when all the Power
Cells are removed.
Loop Power Supply Trans-
former
A Loop Power Supply Transformer is a single-phase step-down transformer. The In-
verter has a Loop Power Supply Transformer on the Top Back Panel of its Input
Section. It drives a high current through a loop of wire.
Main Contactor
The Main Contactor is a medium voltage, vacuum bottle contactor. It is in the Input
Section of the Inverter. Once the Power Cells have been charged through the Pre-
charge Resistors, the Main Contactor closes to connect the Medium Voltage DC in-
put from the 2-Position DC Landing Pad directly to the two DC Bus Bars in the in-
verter.
Main Contactor Relay
The Main Contactor Relay is a plug-in, single pole, double throw relay with a status
indicator light. It is in the Low Voltage Section of the Inverter. It interposes a 24VDC
relay on the Computer Card to the 120VAC coil of the Main Contactor.
Modular Fan Assembly
A Modular Fan Assembly is a ventilated housing that contains a single fan. The fans
remove heat from the (enclosures?) by blowing air out of (it/them?).
Outer Air Filter
An Outer Air Filter is the first stage of a two-stage air filter. It is located outside the
enclosure.
Pole Filter
A Pole Filter is a metal tray that contains multiple reactors electrically arranged to
create two ends and one midpoint. There are three Pole Filters in the Cell Section of
an
Error! Reference source not found. . Each end connects to one Arm of Power
Cells in a phase. The midpoint is connected to the 3-Position AC Landing Pad for
the
Error! Reference source not found. ’s output. The pole filters reduce current
flow between the positive and negative Arm of Power Cells in the phase.
Power Cell
The Power Cells in the Inverter are metal boxes that contain IGBTs, capacitors, cir-
cuit boards, and voltage and current sensors. By switching the IGBTs to different
states, each Power Cell is capable of outputting three different voltage levels. Multi-
ple Power Cells are connected in series to create a multi-level phase, and three
phases are combined to produce the
Error! Reference source not found. ’s output.