General Specifications MTI/ NexTec Trolley Locomotives
Frame: MTI/NexTec locomotive frames are unique structurally sound welded frames utilizing CNC cut quality steel carefully inspected and specified. On completion of fabrication all frames are blasted in a large Wheelabrator which removes blemishes and allows detailed inspection of all welds and bend lines to ensure structural integrity.
Wheels: All wheels are cast from a high grade of abrasion resistant steel to MTI specifications. Wheels are mounted via fasteners to wheel hubs. The wheel hubs are spline fitted to the axles to ensure the highest integrity of fit..
Axles: MTI/NexTec axles are designed for maximum loads and are carefully manufactured from high quality alloy steel with high factors of safety. Axles are press fit and keyed to main drive worm wheels.
Gearing: All MTI/NexTec Locomotives are manufactured utilizing time tested and proven double enveloping worm gears. These gear systems have a long history of application in military, petroleum, crushing and many other applications requiring high power density combined with heavy duty reversing applications. Since 1998 the double enveloping worm gear systems have been proven in locomotive applications in mining, tunneling and industrial applications .The gear set being utilized on the 60HP / 45KW drives are rated for heavy duty application gear drive systems up to double that rating.
Suspension: The standard suspension used by MTI / NexTec Locomotives is a chevron suspension designed around parameters well known to the locomotive industry and proven in countless mine and tunnel rail haulage applications.
Motors: The DC drive motors supplied are series wound and built to exacting standards with a standard base load speed of 1400 RPM. The motors utilized in the trolley application are designed for operation on nominal 250 volts DC input power. The motors utilized are totally enclosed, one hour rated and series wound. These motors are rated to BS1727 (With equivalent EU ratings) and are class H insulated. They are designed for operation at an ambient temperature of 40 Deg Celsius and at an altitude of up to 1000M ABMSL. These motors are fitted with thermal overload cut out with N/C contacts.
They are designed and built for flange mounting on the MTI/ NexTec gear box. In addition to building NexTec Locomotive motors our supplier builds motors for the petroleum, nuclear, defense and other heavy industrial applications.
Controller: The ICON3, Battery Electric Controller installed by MTI on trolley locomotive applications was developed to meet the discriminating requirements of the world’s mining and tunneling industries. (A separate document is available which describes in detail the many features of this controller which is in widespread use in hot deep mines as well as in high altitude mines.) Some features of this controller include: The ICON3 Dual Parallel is a solid state microprocessor controlled, dc series wound traction motor controller comprising a programmable control computer, a power electronic stack, operator control “speedpot” (operator control handle) assembly, and an operator interface with visual indication and audible alarm. The controller model is CNTRLDCTL-003-, Dual parallel, 250Vdc, 140 Amps, 60hp , microprocessor controlled, underground IGBT Trolley Line Locomotive Controller to control 2 x 250 v traction motors connected in dual parallel, complete with the following pertinent features:
- Electric braking
- Controlled reverse braking
- Neutral braking
- Unique programmable coded keys
- Overspeed governor
- Stall protection
- “Thermal” overload protection
- Operator interface with fault indication
- Watchdog safety circuit
- Isolated power supply
- Modular construction
- Vigilance control
- Auto shut down
Options included with this offer include tandem connections and radio remote controls designed for seamless integration with the ICON 3 controller.
Pantograph: A standard Canadian designed pantograph is offered as standard equipment.
This design has been widely used in locomotive application of up to dual 200HP/149KW from 250Volt power supplies.
Braking: The MTI / NexTec trolley locomotive is fitted with heavy duty gear shaft mounted spring-applied, air-released brakes for emergency and park brake functions. Service braking is provided by dynamic feedback in the ICON 3 Controller.