Stationary
Megatron
Resistive/Inductive
400Hz
80KVA, .75PF
120KVA, .75PF
160KVA, .75PF
200KVA, .75PF
233KVA, .75PF
266KVA, .75PF
Megatron
Load Bank
The Simplex Megatron
Load Bank is a portable test instrument which applies a discrete,
selectable electrical load to an AC power source and measures
the response of the power source to the applied load.
The Simplex Megatron is precision instrument used to test,
prove and maintain a 400Hz power supply.
The Megatron is designed
to test 400Hz, 208V or 416V, 3-phase power supplies and generators
by applying resistive/inductive load in increments of 1000W at
.75 power factor. The Megatron is available in six capacities:
60KW, 90KW, 120KW, 150KW, 175KW and 200KW. The Load Bank includes
a complete set of test instruments.
The Simplex Megatron is a totally self-contained and portable
unit. It can be operated in the field, independent of any external
power source, by drawing all required control power from the
source under test. Alternatively, the Load Bank may be switched
to external control power, when available, to remove any parasitic
load from the source under test.
Applications
UPS Systems
400Hz inverters
Ground Power Units
Aircraft power generators and inverters
400Hz engine generators
Computer, telecommunications power systems
Features
Self-contained load and control system
Utilizes
the UL Recognized, “Powr-Web” load elementBranch circuit fuse protection of load elements
Inductive load elements
Capacity 60KW, 90KW, 120KW, 150KW, 175KW, 200KW; Resistive/Inductive, .75 power factor Voltage 208/120VAC or 416/240VAC Frequency 400 Hertz Connection 3-phase, 3-wire wye Load Steps 50 KW resolution standard 1-5-10-25KW resolution available Fan/Control Switch selectable, internal/external. External: 200-240VAC, 1-phase, 50/60Hz, 20A Internal: Balanced 3-phase parasitic load, 4KW Ambient Air Temperature 50°C Load Element Fuses One set of fuses per 3-phase, 50A branch or per step, whichever is less. 200,000AIC. 600V fuses. Airflow 8,000 CFM Duty Cycle Continuous Dimensions and Key Features Diagram Stationary Load Banks: Applications and General Specifications, Features and Options, and Engineer’s Specifications |
Principle Systems and Components
Load System
Independently controllable resistive and inductive load elements. Load can be applies in any increment of 1000W and 800VAR. Resistive and inductive elements are balanced to obtain .75 P.F. by the applications of complementary resistive/inductive steps. Load steps are controlled by magnetic contactors which are manually energized by switches on the control panel. The standard Load Bank provides balanced 3-phase load stepping.
Control System
The Load Bank control panel includes the load step switches, protection circuit alarm indicators and test instrumentation. All load steps are controlled by magnetic contactors which are activated by panel switches, one switch for each resistive step and each inductive step. In addition, a Master Load switch is provided to permit application of block loads. The Load Bank is monitored for system failures, including fan failure, overtemperature, ground fault and underfrequency (to protect inductive elements). Failure detection results in opening of contactor control circuit and activation of panel alarms light. An internal power supply provides control power of 24VDC for the load step contactors and protection circuits and 180VDC for the fan motor. The input to the control power-supply is switch selectable to either the power source under test or to an external 200-240VAC, 1-phase, 50/60Hz source. A 15' cable with plug is included for connection to external control power.
The standard Megatron includes a complete set of 3-phase instruments: voltmeter, ammeter, frequency meter, kilowatt meter, kilovar meter and power factor meter. With standard load stepping, voltmeter and ammeter phase transfer switches are provided to measure phase-phase voltages and phase currents.
(.75pf) |
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Control Panel
Load Application
Controls
Load step switches: one toggle switch for each resistive and
each inductive step as listed on facing page. Each switch controls
internal contactor(s) associated with load elements which comprise
the step.
Master Load switch: Permits one-step application of pre-programmed
block loads.
Test Instrumentation
The Simplex Megatron includes the test instruments listed
below. Standard instruments are 3½" square, ±2
accuracy, 100° scales, analog type.
AC voltmeter, 0-300V or 0-600V scale
Voltmeter phase transfer switch, L1-L2/L2-L3/L3-L1/OFF
AC ammeter, nominal 15% overscale
Ammeter phase transfer switch, L1/L2/L3/OFF
Frequency meter, 360-440 Hertz scale
Kilowatt meter, nominal 15% overscale
Kilovar meter, nominal 15% overscale
Power factor meter, 0.2 lag - 1.0 P.F. scale
Systems Controls
Control Power Switch: Selects power source for load step contactors,
fan motor, protection circuits. Selects control power off, Control
power on - internal, control power on - external. Internal power
source is the source under test, and represents a parasitic load.
External power is standard utility power and is connected via
a 10" external power cord provided standard.
Protective Circuits: The Megatron is continuously monitored
by internal sensors for the following failure conditions: Fan
Failure, Over Temperature, Ground Fault, andUnderfrequency
Interlocks between the protection circuits and load step control
circuits act to instantly remove all load and activate an alarm
in the event of a system failure.
Powr-Web Load Element
Simplex Load Banks utilize the
UL Recognized, “Powr-Web” load element. The “Powr-Web”
is an advanced design, air-cooled power resistor specifically
designed for application to load bank systems. The “Powr-Web”
is conservatively operated at half the maximum temperature rating
of the alloy and features a short-circuit-safe design based on
continuous mechanical support of the resistor by high temperature,
ceramic clad stainless steel rods. The “Power Webs”
are assembled into discrete trays which are assembled in a vertical
“stack.” Each tray in the “stack” is independently
serviceable without disturbing adjacent trays.
Ratings
3333W at 120V
4170W at 139V
8333 watt 240/480V
16,777 watt at 480V
Specifications
Alloy: FeCrAl
Max. continuous temp. rating: 1920°F
Maximum operating temperature as applied in Load Bank: 1080°
F
Cool down time from operating to ambient temperature: 10 seconds
Construction
Calibrated to specific
ohm value
Welded lugs on each end
All load elements are continuously supported by vibration resistant,
ceramic clad, stainless steel throughrods
Inductive Load
Elements
These discrete iron-core load elements are non-saturable, air gap calibrated, air cooled devices and field replaceable. Elements may have a temperature sensor embedded in the windings used to detect element overheating and activate the malfunction detection system which disconnects the load elements and activates an alarm. Standard elements are varnish coated; epoxy coatings are available for severe environments.
Specifications
Tolerance: 5%
Maximum Harmonic Distortion: 1%
Power Factor: .05
Insulation: 220°C
Cooling: Air
Branch Circuit
Fuse Protection
The load of a Resistive Load Bank consists of a dense array of open, uninsulated power resistors mounted within a cooling air stream. Since the elements are electrically live, it is possible for a foreign object to penetrate the element array and create a short circuit of adjacent elements or a short to ground. Since the elements are densely packed, it is possible for a short circuit, once started, to rapidly propagate through the entire element array. As a Load Bank represents a relatively large amount of power concentrated within a relatively small volume, a self-propagating, cascading short circuit would have catastrophic results.
Simplex virtually eliminates
the dangers of short circuit through the use of branch circuit
fuse protection of the load elements. Per NEC 110-10, protective
devices shall clear a fault without “extensive damage”
to the circuit components. A Simplex Load Bank is divided into
branch circuits of not more than 50 KW each.
Options
The standard Megatron is supplied with balanced 3-phase loadstepping. Option Groups A and B provide alternate load application schemes.
Option Group A
Division of loads into single-phase controlled increments. Requires 4-wire power source. All load elements connected line-neutral. Steps applied to each phase independently. Nominal .33KW/.29KVAR load resolution per phase. Master load switches for each step permit programmed 3-phase load to be applied. Option includes instrumentation to measure L-N voltage, kilowatts, kilovars and power factor.
Option Group B
The standard Megatron and Option Group A, consist of fixed value load steps in multiples of 1KW/.88KVAR (3-phase). Option Group B substitutes infinitely variable load step rated 0-1KW/0-.88KVAR for smallest fixed steps. Option includes manually controlled variable autotransformer and load step contactors. When ordered with Option Group A, one infinitely variable step per phase is provided rated 0-.33KW/0-.29KVAR.
Option Group C
Substitution of 4½", ±1% accuracy, 250° scale instruments for standard 3½", ±2% accuracy, 100° scale instruments.
Option Group D
Substitution of digital instrumentation for standard 2% instruments. Digital instruments are 3½ digit, .05% resolution, .05% accuracy, .55" display.
Option Group E
Addition of chart recorders associated with any of all of test instruments.
Option Group F
Addition of thermal numeric printers driven from data output of digital instruments, Option Group D.
Standard Megatron supplied with termination of load at bus bar terminal block which will accept connection of lugged cables. Select from connection options below to tailor Megatron to your specific application. Multiple connection options can be ordered.
Option Group H
High-flex copper wire leads; L1-L2-L3-N-G; 10 feet, with lugged end.
Option Group J
High-flex copper cable, all lines, N&G, single cable, terminated in plug. Specify type plug/receptacle required.
Option Group K
Fixed plug or plugs mounted within connection compartment. Specify type plug/receptacle.
