Joliet Technologies recently shipped a Siemens 6RA70 DC Drive and GE 752 Traction Motor to Hallett Materials in Des Moines, Iowa.

Joliet Technologies Variable Speed Drive Systems and Controls… 

A recent project we shipped to Hallett Materials in Des Moines, IA. Hallett Materials is a division of Oldcastle Materials, the leading vertically integrated supplier of aggregates, asphalt, ready mix concrete, and paving services in the United States. Annually they produce 136 million tons of aggregates, 38 million tons of asphalt, and 6.6 million cubic yards of ready mix concrete at more than 550 locations nationwide.


Joliet Technologies provided a GE 752 DC Shunt Wound Traction motor with a SIEMENS 6RA70 DC Digital SCR (Silicon Controlled Rectifier) Drive Controller System for a Dredging Application.

DC Motor

AmeriMex Remanufactured GE 752 DC Shunt Wound Traction Motor, rated at 750HP.

AmeriMex Remanufactured GE 752 DC Shunt Wound Traction Motor, rated at 750HP.

Remanufactured GE 752 Shunt Wound DC Traction Motor, rated at 750HP, 1040RPM, 750VDC armature, 50.5 amp field, forced ventilated, supplied by AmeriMex Motor & Controls, Inc. of Houston TX, with the following features:

  • Shunt Field
  • Marine type stainless steel pressurized junction box
  • Lockout Device
  • Pressure Switch
  • Anti-friction grease type ball bearings
  • 100 ohm Platinum RTD’s installed and terminated
  • Single Shaft Extension
  • Tachometer
  • 10 HP, 3600RPM, 460 VAC Stainless steel cooling blower
  • Heater installed and wired
DC Drive Cabinet w/Operator Devices and 12,000BTU Air Conditioner Mounted on Door.

DC Drive Cabinet w/Operator Devices and 12,000BTU Air Conditioner Mounted on Door.

DC Drive

Drive systems consists of a Siemens 6RA70 DC digital drive package, with ratings of 850 ADC. Drive is a one quadrant. Drive will be mounted and wired in a modified one door, Nema 12 enclosure with a 1200 amp MCS and a through the door disconnect. The System has field supply transformer 600/230 VAC, for 50.5 amp rated motor field. Drive contain the following features:

  • Fully digital regulation and primary control via 16bit 38mhz microprocessor with 64 layers of priority
  • 5 digit LED digital display and keypad with straight forward programming
  • Optional LCD keypad with alpha numeric parameter entry and fault diagnostics
  • Parameter displays provide numerical indication of each adjustment set point and monitor drive data
  • Diagnostics display for start up and troubleshooting with 120 messages, including fault indication with memory retention in case of power loss.
  • Self-tuning routine allows automatic optimization of response loops.
  • Regulated shunt field power supply with current loss detection, time delayed field economy and constant HP extended speed range.
  • Ac current limiting fuses.
  • Instantaneous over current protection.
  • Phase loss protection
  • Phase sequence insensitive.
  • Heat sink over temperature.
  • Tachometer feedback regulation
  • Isolated electronics
  • Fast, precise regulator loops in the current, speed and CEMF controllers.
  • RS232 and RS485 serial communications interface.
  • 14 bit analog input resolution.
  • 5 binary outputs (programmable)
  • 5 analog outputs (programmable)
  • Mathematical function blocks for diameter calculation
  • Four-layer parameter adjust.
  • Elapsed operating time log
  • Designed to meet UL, CSA, and IEEE specifications.
  • Adjustments via keypad:
    • Maximum speed
    • Minimum speed
    • Jog speed (forward)
    • Linear acceleration
    • Linear deceleration
    • Current limit motoring
  • Remote Operator Station.

    Remote Operator Station.

    Operator Devices on Door:

    • Meter 0 – 10 VDC 0 – 150%
    • Meter 0 – 10 VDC 0 – 1150 RPM
    • 10k Speed Potentiometer
    • Illuminnated Start PB
    • Jog PB
    • Stop PB
  • 12000 BTU cooling unit mounted on cabinet door and wired into cabinet.