Vector

NFPA Testing

Simplex Stationary Load Banks can be used to satisfy the requirements of the National Fire Protection Association (NFPA) for emergency stand-by power systems. These requirements concern acceptance testing and periodic on-site testing and maintenance of emergency and stand-by power systems.

The essence of the requirements is that emergency and stand-by power systems are to be tested under load.

• NFPA 110 - Emergency and Standby Power Systems, Sections 5-13, 6-3, 6-4
• NFPA 99 - Health Care Facilities, Section 3-4.4.1.1 (b)
• NFPA 70 - National Electric Code, Section 700-4 (b)

Pow'r-Rod Load Elements

Simplex LBD Load Banks utilize UL Recognized, industry leading "Powr-Rod" load elements specifically designed for load banks.

Simplex Pow'r Rod Load Elements are UL recognized. These elements are totally enclosed, sealed and weatherproof. Pow'r Rod elements consist of nickel-chromium resistance wire electrically insulated and sealed within a metallic sheath. The hazard of electric shock to personnel and the danger of short circuit by foreign object penetration are reduced since the elements are electrically dead on the outside. They will not fatigue from engine or air-blast vibrations and will not sag or stretch if overheated. The sheath material is "incolloy", a rustproof nickel alloy with a very high temperature rating (1600°F). These elements do not require a cool down period.

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.

Auto Load Regulation

The auto load regulation option’s main function is to maintain a minimum load on the generator at all times consistent with recommended operating practices for diesel engine generators sets.

This is accomplished by maintaining total generator load within a preset bandwidth when external load demands on generator set are present.

A PLC controller senses generator load and automatically adds or subtracts load bank steps in order to maintain total generator load at a desired level. The controller senses amperage or wattage. Load banks with the Auto Load Regulation option allow for adjustable minimum and maximum load level and load step addition and subtraction delays.

Load banks with this option may also be operated manually for service, set-up or as a back-up and when used to exercise/test/adjust/maintain the diesel generator set.

Auto Exercise

The Auto Exercise option provides automatic incremental load step addition and subtraction during generator exercise.

This is initiated by switch closure signal from generator, switchgear, or customer supplied control circuits. As the exercise signal is present the load bank will increment load on the generator until the load bank has reached full load.

The load bank will maintain at full load until the exercise signal is removed and will then decrement load until the load bank is consuming no load. The load bank then goes into cool down mode. Increment and decrement delays are customer field adjustable.

Load banks with this option may also be operated manually for service, set-up or as a back-up and when used to exercise/test/adjust/maintain the diesel generator set.

Regenerative Power Protection

Load banks with Regenerative Power sensing, will be on-line whenever the generator runs. It provides a dual function: to maintain a minimum load on the generator at all times consistent with recommended operating practices for diesel engine generators sets and to provide a load sink for regenerative power from inertial loads (such as elevators, ski lifts, cranes).

As a load sink for regenerative power, the load bank would be active during periods when the facility loads exclusive of the inertial loads were relatively light and therefore unavailable as a sink for regenerative power. This would be a situation typical of nighttimes when the only building loads other than the elevators may be exit lights.

By providing for minimum generator loading, the load bank insures that a minimum value of load is always on the generator and hence insures that power direction should never transition through zero to reverse power. Whenever generator load is less than the minimum load set point of the sensors, load will be added to the generator by the load bank.

When load exceeds the maximum set point, the load bank will step-down to remove load.  In the event that reverse power is sensed, the load bank will automatically and instantaneously apply additional load to verify that reverse power is not absorbed by the generator.

Load banks with this option may also be operated manually for service, set-up or as a back-up and when used to exercise/test/adjust/maintain the diesel generator set.