DC7000 load bank
3100kW | 0 to 7000A and up to 2000V DC
Key features
For performance testing of diesel electric locomotives up to 4000hp rating, with easy-to-use resistance adjustments.
DC capacity
3100kW, 0 - 7000A continuously at up to 2000V DC. The load consists of twin 14-section fan-cooled resistor ducts with fans, starters and controls. The optional two main load isolating contactors and an integrated off-load switch panel permitting the pre-selection of any one of more than 200 values of resistance between 0.026Ω and 3.3Ω.
Connection scheme
The off-load knife switches allow for the reconnection of the twelve resistors in each stack into more than 200 different configurations with a range from .026Ω/7000A through to 3.3Ω/600A. There are intermediate points to suit the majority of loco alternators up to 300hp rating.
Construction
The fans, resistors and switchgear are all built in to a single sheet steel frame with hinged lockable access doors, air intake screens and (optionally) hand-operated outlet louvres. Paint finish is RAL9002 grey powder coat the enclosure is designed for floor mounting with bottom cable entry. Fan motor and control voltages are set to suit customer’s own available supply voltage and frequency.
Resistor element
Flat strip elements, type EN Each bank is contained in a fully insulated duct section with two independent levels of 3kV electrical insulation. The resistor elements are manufactured from a 60:23 nickel-chrome stainless steel. This is a high-grade stainless steel with excellent corrosion resistance properties and a low (0.12%/°C) temperature coefficient of resistance, giving very stable resistance values over the whole range of operation.
Technical specification
Ratings
Maximum voltage 2000 V DC
Maximum current 7000 A
Maximum capacity 3126kW
Control and Ventilation
Manual controls
14 x Off-load knife switches
on/off push button control for fans
1 x local emergency stop
Instrumentation
1 x 4000A/1mV shunt
1 x Digital power meter with 4-20mA output
Cooling Forced convection, vertical orientation, horizontal outlet
Fans 2 x 27kW AC fan, axial type
Control supply 3-phase AC, voltage and frequency to suit order
Source External supply
Load controls Main load connections to suit order, 2 x M12 PE bonding
External control supply To suit order
Connection Interfaces
Suitable for Indoor use only
Ambient temperature 5°C to 40°C
Ingress protection
IP23 load enclosure
IP54 Control cabinet
Operating Environment
Construction
Resistor elements Steel strip
Element material 60-23 NiCr high grade stainless steel
Main enclosure Sheet steel, painted RAL9002 grey
Exhaust air duct Stainless steel grade 304L, un-painted 2B finish
Weight and Dimensions
Length 2750mm
Width 1900mm
Height 2650mm
Weight 2700kg
Access protection Lockable cabinet doors, interlocked with trapped key isolator safety logic
Thermal protection Airflow status alarm via pressure switch
Safety
Optional extras
Main Contactors – The two main contactors carry the maximum continuous thermal current of 7000A and have a peak breaking capacity of 1000A, allowing for on-load isolation from the locomotive generator after the excitation has been reduced. For safety, the contacts are mechanically latched and have a separate trip coil so that there is no possibility of accidental opening during testing.
Weather proof louvres – For periods of long term storage it is recommended to protect the load bank from water and particulate ingress. Optional extra is to have hand-operated weather proof louvres integrated into the outlet ducts can provide this protection.
Documentation downloads
Technical data sheet PDF