1. Product Overview
The MR717E training unit integrates a 3-phase squirrel-cage asynchronous motor and a DC compound-wound motor, designed for electrical engineering teaching in colleges and vocational training labs.
The DC compound-wound motor stator has two independent excitation windings: a series winding and a shunt winding. The series winding uses fewer turns of thicker wire, connected in series with the rotor armature circuit and carrying armature operating current. The shunt winding consists of many turns of thinner wire, paralleled across the power supply and carrying a small constant excitation current. This combination brings two core advantages: high starting torque and good rotational speed stability.
 
2. Technical Specifications
The equipment adopts a three-phase five-wire power system with rated voltage of 400V, 50Hz. It works within ambient temperature from -10°C to +40°C, and the relative humidity should be less than 85% at 25°C.
The overall dimension is 530mm × 230mm × 220mm, and total weight is under 20kg. Compact and lightweight structure facilitates transportation, layout and storage in laboratory environments.
 
3. Product Components and Functions
The main unit contains one DC compound-wound motor, one coupling and one three-phase squirrel-cage induction motor. The coupling connects the two motor shafts mechanically to transfer power between AC and DC motors for coupled experiments.
A full set of color-coded accessories is supplied: 2 pieces of 1m double-ended 4mm yellow safety cables, 2 green cables, 5 red cables, 2 blue cables and 5 black cables. These safety connection cables support standardized and reliable wiring for all experimental tests.
 
4. Instructional Experiment List
All detailed operation procedures are documented in the supporting experiment manual. Two core experimental items are available for learners.
The first experiment helps users get familiar with the structure and working principle of the compound-excited DC motor. The second one is the joint operation experiment, where the compound-excited DC motor works with the three-phase squirrel-cage induction motor. Students can observe mutual driving and loading status, and analyze speed and torque characteristics of the motors.
 
5. Summary
MR717E is a compact and safe teaching platform for AC and DC electrical machinery courses. It combines two classic motors in one set, helping students bridge electrical theory and practical operation. This training unit is suitable for classroom teaching, skill assessment and laboratory demonstration of electric machines.