Large
Portable

Electra
660KW
560KW
460KW

Electra
Portable Load Bank

The Simplex Electra is a very large capacity, high performance Portable Load Bank designed to provide the manufacturers, distributors and users of large AC generators and UPS systems with sophisticated testing capability.

The Electra provides 460KW, 560KW or 660 of resistive load at both 240V and 480V, 3-phase. It can be applied at any AC voltage to 480V AC, 50-60-400 Hertz, single or 3-phase. Load step resolution is 5KW.

The Electra is a totally self-contained testing system. It includes all resistive load elements, load control devices, load element circuit protective devices, connection cable set, cooling system, malfunction detection system, control power supply and test instrumentation.


Principal Sub-Systems

Load Elements: Simplex “Powr-Web” chromium alloy, open wire, continuously supported, power resistor.

Load Control: 3-Pole magnetic contactors.

Load Element Circuit Protection: Branch circuit fuses. One set of fuses each 50KW branch. Fuses are current limiting type, 200,000 AIC, 600V, enabling safe use on large generating or UPS system.

Cooling System: 3-phase, direct-drive fan, 12,500 CFM.

Malfunction Detection System: Protection against fan failure, high exhaust air temperature, high intake air temperature, overvoltage and fan reversal.

Control Power Supply: Dual voltage control power transformer with supply power switchable to internal (generator) or external.

Test Instrumentation: 3½”, +/- 2% accuracy panel meters. Options available.

Remote Control: Load control switch panel removable for remote operation. Connection plugs will accept optional remote control cables.

Connection: 12’ connection cable set including 3-phase power cables, ground cable and external control power cord, stored behind hinged door in rear compartment.

Control Panel

AC instrumentation, 3½”, +/- 2% accuracy panel meters:
AC voltmeter with 3-ph. transfer switch
AC ammeter with 3-ph. transfer switch
Frequency meter

Load step control toggle switches

Master load control toggle switch

Control power switch

Voltage selector switch

Fan reversal switch

Operational indicator lights:
Normal Operation
Overvoltage
Fan failure/over temperature
 

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

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.