Basic Information
Product Description
1. Product Overview
The NMK series modular slip-ring motors are engineered as ideal solutions for heavy load inertia applications that require high starting torque and low starting current. These motors are particularly suitable for demanding environments such as mill drives or situations with weak network conditions. By minimizing mechanical stress during startup, NMK slip-ring motors significantly extend the lifetime of driven equipment while providing maximized availability and high torque across the entire speed range. They are widely utilized in mills, crushers, fans, and conveyors within the mining, cement, and metal industries, as well as for pumps in the water industry and safe area pumps, compressors, and mixers in the petrochemical sector.
NMK motors feature a welded steel frame and are available in shaft heights ranging from 400 to 710 mm, with standard cooling and protection configurations of IC611/IP55 and IC81W/IP55. Rated up to 10,000 kW, the slip ring unit can be supplied with permanent contact brushes or brush lifting gear, with the slip rings enclosed in a separate housing at the N-end. A liquid resistance starter (LRS) is also available upon request. While this catalog highlights typical technical data for 6kV and 11kV at 50 Hz for 4, 6, and 8-pole motors, the complete product scope encompasses 60Hz options, up to 16 poles, and voltage ratings up to 13.8kV.
2. Mounting Arrangements
The standard mounting arrangements for NMK motors include Code I: IM B3 and Code II: IM 1001 (horizontal foot-mounted). Other mounting configurations, such as IM1002, are available upon request.
3. Enclosure and Cooling Systems
Standard combinations for NMK motors are IC611/IP55 and IC81W/IP55, with alternative cooling methods like IC616 and IC86W available on request:
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IC611/IP55: This fully enclosed design features an air-to-air heat exchanger mounted on the motor. Shaft-mounted fans are fitted both inside the motor frame and slip ring housing, as well as outside the casing, to supply the internal and external cooling circuits. The motor is effectively protected against dust and splashing water from any direction.
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IC81W/IP55: This totally enclosed machine utilizes machine-mounted and SRU housing-mounted air-to-water heat exchangers. A shaft-mounted fan inside the casing supplies the internal cooling circuit, ensuring robust protection against dust and splashing water from any direction.
4. Packaging
We provide standard seaworthy packaging for export, utilizing plywood or wooden fumigation packages that are fully suitable for long-distance transportation by sea or land.
5. Warranty Period
Our standard warranty covers 12 months after commissioning or 18 months after delivery, whichever comes first. Extensions to the warranty period are available; please contact us for further details.
