- Both the PUTAI made YTM and YMPS are three-phase asynchronous motors designed for high-voltage coal mills (6kV/3kV/10kV, IP54, Class F insulation, IC611/IC81W cooling). The core difference lies in the specific type of coal mill they are adapted for and their starting torque ratings.
- Simply put: the YTM is designed for low-speed drum-type mills, while the YMPS is designed for medium-speed MPS bowl-type mills; furthermore, the YMPS features a significantly higher starting torque.
Model Nomenclature and Application
YTM
Y (Asynchronous) + T (Drum-type) + M (Coal Mill) → Specifically designed for low-speed drum-type coal mills (ball mills).
YMPS
Y (Asynchronous) + MPS (Medium-speed bowl mill model) → Specifically designed for medium-speed MPS bowl-type coal mills.
Core Performance Differences (Based on Standard JB/T 7128)
Locked-Rotor Torque (Starting Torque)
- YTM: ≥ 1.5 times rated torque (Standard heavy-duty application).
- YMPS: ≥ 2.8 times rated torque (Heavy-duty application with high-inertia starting).
Locked-Rotor Current
-
YTM: 6-pole ≤ 7.0 Ie; ≥ 8-pole ≤ 6.5 Ie.
-
YMPS: 6-pole ≤ 7.5 Ie; ≥ 8-pole ≤ 6.8 Ie (Slightly higher, designed to match the higher torque output).
Rotor Structure
- YTM: Cast aluminum cage rotor, sufficient for general starting requirements.
- YMPS: Copper bar cage rotor, capable of withstanding greater starting impact and thermal stress.
Operating Conditions and Selection Criteria
YTM:
Used in power plants and mines for low-speed ball mills; characterized by moderate starting resistance and high inertia, requiring stable, reliable operation and high thermal capacity.
YMPS:
Used in power stations for medium-speed MPS bowl mills; characterized by high grinding pressure on the coal powder and more demanding starting load conditions, requiring high starting torque and resistance to frequent impact loads.
Common Features
Voltage:
6kV (3kV optional), 50Hz. • Protection: IP54; Insulation Class F; Continuous Duty (S1).
Mounting:
IMB3 (Horizontal); Shaft Center Height H400–H800; Power Output: 200–10,000 kW.
