Power Supply
Main Supply
Used to supply power, both DC and AC, to all of the laboratory
experiments.
The four main supplies are turned ON and OFF by a single power
switch.
L1, L2 and L3 are lit to signify power in each phase.
Supplies are available on the colored 4mm safety banana receptacles
labeled 1-8, N and -N.
A analog voltmeter connected through a selector switch monitors the
supply outputs.
- Fixed 120V/208V - 15A Three-phase Supply
- Fixed 120V - 25 A DC Supply
- Variable 0-120V/208V - 15A Three-phase Supply*
- Variable 0-120V -8 A DC Supply*
the variable supplies are both controlled by the same main
variac.
Accessories Supply
Used to power accessories, mainly the Data Acquisition and Control
Interface.
Controlled by the accessories switch
The output is available on the barrel connector.
- Fixed24V - 3A Single phase AC
The Power Supply module is the primary component of the system. All
associated equipment is powered by this power supply. A flexible, 5-wire
power cord, terminated with a 5-prong, twist-lock plug and line cap,
feeds the module. A mechanical interlock on the line cap prevents the
removal of an energized Power Supply from its locked position in the
workstation. The Power Supply requires a 3-phase, wye-connected, 5-wire
service installation. An appropriate wall outlet is shipped with each
Power Supply so that site power can be properly
terminated to receive the power cord. In addition to the 3-phase legs
and the neutral, a separate copper ground provides proper grounding for
the Power Supply chassis and workstation cabinets, thus ensuring added
safety for students using the equipment.
The Power Supply provides fixed and variable AC and DC voltage
sources all terminated with 4-mm safety jacks. They can be used
simultaneously, up to a total load current equal to the rating of the
fixed 3-phase output. Independent circuit breakers, reset at the front
panel, protect the Power Supply input and outputs. Indicator lamps
monitor the presence of input voltage in each phase. When a phase leg of
the site power service is out, the lamp goes off to reflect this
condition. A voltmeter, connected through a selector switch, monitors
the outputs.
Passive Loads
The Lab-Volt 0.2 kW Electromechanical Training System (EMS) features
four electrical load modules: the Resistive Load, Model 8311, Inductive
Load, Model 8321, Capacitive Load, Model 8331, and the Inductive and
Capacitive Loads, Model 8333.
Each model comes as half-size EMS module. The loads are identified on
the module front panel by schematic symbols and enabled using toggle
switches. Connections are made through 4 mm safety banana jacks.
Models 8311, 8321, and 8331 are equipped with nine load components
(resistors, inductors, and capacitors respectively) arranged in three
identical groups for balanced or unbalanced, 3-phase delta or star (wye)
loading. Each group can be independently varied in seven steps of
loading. The three groups can also be connected in parallel to create a
single-phase load variable in 21 steps.
These models provide impedance levels that are adjustable for load
equality, allowing students to measure the effects of indentical
resistive and reactive loads on voltage and current in a circuit, as
well as observe, using a wattmeter or a varmeter, the differences that
each type of load has on an ac signal source. Furthermore, because
complex loads are possible through the interconnection of these models,
power factor correction and resonance phenomena are easily demonstrated
in laboratory exercises.
The Inductive and Capacitive Loads module, Model 8333, is equipped
with twelve load components (six inductors and six capacitors) and each
type of load components is arranged in two identical groups. This model
has been specifically designed for the Renewable Energy Training Systems
(Series 8010) to familiarize students with reactive loads in
single-phase ac power circuits at a reduced network voltage of 100
V.
Resistive Load
The Resistive Load Module, Model 8311, is equipped with 9 wire-wound
power resistors. Each resistor is identified by a schematic symbol, the
resistance value, as well as the current that will flow through it when
connected to a nominal voltage power source. Each
resistor is within 5% tolerance of the stated resistance value.
Inductive Load
The Inductive Load Module, Model 8321, is equipped with 9 iron-core
power inductors, which have a nominal Q of 10. Each inductor is
identified by a schematic symbol, the inductance value, the inductive
reactance, as well as the current that will flow through it when
connected to a nominal voltage power source. Each inductor is within 5%
tolerance of the stated inductance value
Capacitive Load
The Capacitive Load Module, Model 8331, is equipped with 9 oil-filled
capacitors. Each capacitor is identified by a schematic symbol, the
capacitance value, the capacitive reactance, as well as the current that
will flow through it when connected to a nominal voltage power source.
Each capacitor is within 5% tolerance of the stated capacitance value. A
permanently connected discharge resistor reduces the voltage across each
capacitor group to 5% of the applied voltage within 15 seconds after the
load is disconnected from the supply.
Connection Leads
The Connection Leads consist of PVC-covered, extra flexible leads
terminated with stacking 4-mm safety banana plugs. The leads are
supplied in three different lengths, according to model variations, and
are color coded according to length. The leads are supplied with a lead
holder that can be mounted to the side of any EMS Workstation, providing
easy access and orderly storage of the leads.
