Technical Specifications

ManualsBrandsEmerson ManualsLoad BanksEmerson 500-1250KW (K575A) Load Bank

8/2011-RevA (K575A)

ENGINEERING SPECIFICATION

FOR HORIZONTAL

OUTDOOR RESISTIVE LOAD BANK

(750, 1000 AND 1250KW)

1.0 SCOPE

1.1 This specification contains the minimum requirements for the design, manufacture and testing of an outdoor

weatherproof resistive load bank.

1.2 The load bank is required for periodic exercising and testing of the standby emergency power source. The load bank

shall be permanently mounted in a weatherproof enclosure, forced air cooled with a remotely mounted control panel.

1.3 This specification shall apply if the load bank is supplied to the purchaser or as a part of other equipment.

1.4 Should the vendor take exception to any part of this specification, it shall be stated in the bid with item number

referenced.

2.0 STANDARDS

2.1 The equipment covered by this specification shall be designed as it applies with the latest standard of NEMA, NEC,

ISO and ANSI standards.

3.0 RATINGS

3.1 The total capacity of the load bank shall be______KW at________Volts, 3 Phase. 60 Hertz, with_______Amps per

Phase with Unity Power Factor with 50KW minimum load step resolution.

VOLTS

AMPS/PHASE

750

480

901

1000

480

1202

1250

480

1502

3.2 The duty cycle shall be continuous and the load bank shall operate in an ambient temperature of -28°C to 49°C

(-20°F to 120°F).

4.0 CONSTRUCTION

4.1 The load bank shall be constructed of heavy gauge aluminized steel per ASTM A463 or coated mild steel that meets or

exceeds physical and chemical performance of polyurethane enamel coatings. Galvanized steel has a low corrosion

threshold and shall not be used for exterior load bank construction.

4.2 The main input load bus, load step relays, fuses and blower/control relays shall be located within the load bank

enclosure. A thermostatically controlled heater shall be located within the control section to protect control devices

from the effects of moisture and condensation.

4.3 The load bank shall be outdoor weatherproof construction. All exterior fasteners shall be stainless steel. The load

bank shall include forklift channels in the base for lifting.

4.4 For maximum protection and reliability in an outdoor environment, airflow shall be horizontal screened air intake and

fixed louver shall be provided at the exhaust.

4.5 The exterior of the load bank shall be painted with polyurethane enamel paint at a minimum 2 MILS dry film thickness

with a spatter finish.

4.6 Load elements shall be contained in one or more resistor cases or trays. Each can be removed in their entirety as a

unit if service becomes necessary.

5.0 RESISTIVE LOAD ELEMENTS

5.1 Load elements shall be Avtron Helidyne™, helically wound chromium alloy de-rated to operate at approximately ½ of

maximum continuous rating of the wire. Elements must be fully supported across the entire length within the air stream

by segmented ceramic insulators on a stainless steel rod. Element supports will be designed that should a wire break,

it will not short to adjacent conductors or to ground.

Summary of content (2 pages)

PAGE 1
ENGINEERING SPECIFICATION FOR HORIZONTAL OUTDOOR RESISTIVE LOAD BANK (750, 1000 AND 1250KW) 1.0 SCOPE 1.1 This specification contains the minimum requirements for the design, manufacture and testing of an outdoor weatherproof resistive load bank. 1.2 The load bank is required for periodic exercising and testing of the standby emergency power source. The load bank shall be permanently mounted in a weatherproof enclosure, forced air cooled with a remotely mounted control panel. 1.
PAGE 2
5.2 The change in resistance due to temperature shall be minimized by maintaining conservative watt densities. The overall tolerance of the load bank shall be –0% to +5% KW at rated voltage. A –5%, +5% rating allows the load bank to deliver less than rated KW and shall not be used. The load bank must deliver rated KW at rated voltage. 6.0 COOLING 6.1 The load bank shall be cooled by an integral TEFC or TEAO motor which is direct coupled to the cooling fan blade.