Affordable motor protection
November 2001
Motion Control & Drives
The locally designed and manufactured N Series motor protection relays, from NewElec, range from the NC relay offering basic protection to the more sophisticated NJ model. All types provide simple operation and reliability. The four models cover the current ranges 5 to 55 A, 20 to 220 A, 50 to 550 A and 10-110% of selected CT ratio, to accurately protect LV three-phase induction motors against overloads, phase unbalance, earth leakage and jam protection.
LED indication is provided for ease of operation. During a thermal lockout fault condition, a red LED indicates that the overload protection circuit has operated and that the thermal capacity available is less than 60% of the set value. This LED switches off once 60% capacity is available.
The earth leakage circuit operates on a core balance principle with a 250 mA sensitivity and a 100 ms trip delay. The main trip contacts of the NH and NJ relays are actuated provided the motor current is below 8 x Ifl. This feature prevents the motor contactor or any other device with insufficient rupturing capacity from attempting to clear a high-energy fault.
Both the NJ and NK relays provide a motor running jam protection feature which protects the driven plant against impact torques developed when jamming occurs during normal running conditions. A 100 ms trip delay is initiated when the motor load current exceeds 3 x Ifl. The NK and NJ relays' interface facility allows their potential free relay outputs to duplicate the red LED fault indicators to communicate with a PLC or telemetry interface.
NewElec
(012) 327 1729
[email protected]
www.newelec.co.za
Further reading:
Driving heavy equipment industry
Motion Control & Drives
Cimolai Technology, a leader in the design, production and installation of lifting and handling equipment, has adopted the Siemens Xcelerator portfolio of industry software. This move aims to deliver innovative, reliable and custom-made solutions to meet the most demanding technical specifications across sectors such as shipyards, infrastructure and heavy industry.
Read more...
Actuators for automated fully
Motion Control & Drives
Rotork supplies actuators for an automated next generation fully electrified offshore gas platform
Read more...
AG Lubricants partners with
Motion Control & Drives
AG Lubricants has partnered with a major player in the South African steel industry to supply high-performance Mobil lubricants, Quaker Houghton industrial fluids and value-added technical services.
Read more...
Smart features increase crane safety
Motion Control & Drives
The newly launched Konecranes S series hoist offers a large bouquet of smart features which not only increase lifting device safety but also deliver a higher level of operator protection.
Read more...
Compact, powerful hexapod for high-precision applications
Motion Control & Drives
With the HEX150-125HL, Aerotech is launching the latest generation of its hexapod technology. The compact six-axis positioner combines precise movements with high load capacity and simple integration.
Read more...
Hexagon Electrical services electric motor sector
Motion Control & Drives
Hexagon Electrical has expanded its manufacturing and service capabilities to meet the growing demand for customised, high-performance specialised electric motors in heavy engineering, and hazardous industrial and mining applications.
Read more...
NORD modular drives for frequently changing motor speeds
Bearing Man Group t/a BMG
Motion Control & Drives
BMG has made a substantial investment over the years to ensure assembly, stockholdings and technical support for the Nord range are in line with stringent international quality, safety and environmental standards.
Read more...
Cutting-edge robotics and smart manufacturing solutions
Yaskawa Southern Africa
Motion Control & Drives
Yaskawa Southern Africa made a compelling impact at this year’s Africa Automation and Technology Fair
Read more...
Medium voltage drive for enhanced energy efficiency and process optimisation
Schneider Electric South Africa
Motion Control & Drives
Schneider Electric South Africa has unveiled its cutting-edge Altivar Process ATV6100 medium voltage (MV) drive range, designed to enhance energy efficiency and operational reliability across various industries.
Read more...
Powerful high-precision hexapod
Motion Control & Drives
With the HEX150-125HL, Aerotech is launching the latest generation of its hexapod technology. The compact six-axis positioner combines precise movements with high load capacity and simple integration.
Read more...
printer friendly version