Eliminating impact torque conditions
4th Quarter 2015
Shaft power components
The OLR 84 S protection relay from NewElec, when mounted on a motor circuit, eliminates impact torque conditions which can result in broken chains, damaged screw conveyors, broken couplings and even damaged gearboxes.
The OLR 84 S relay has two settings. The first designates the total start time for the given motor in seconds through a range up to 50 s while the second designates the load trip threshold. The latter setting is percentage calibrated from 30 to 120% of the selected CT ratio XXX:1. It is necessary for the user to select an appropriate ring CT that will cover the expected trip threshold current. A general rule is that if the motor load maximum current is x A, the user must select a current transformer where 3x A is about mid-scale. The reason for this is that a stall or jam condition usually manifests itself at about three times motor full load when the motor develops an output torque in the region of 2,5 to 3 times its normal rated torque. This output torque will then be amplified through a factor dependent on the gearbox ratio.
The OLR 84 S permits the starting current for the motor start but will cause a trip in 100 ms if the motor load suddenly exceeds the upper trip threshold where the motor enters a stall condition after the starting sequence. In doing so, it will interrupt the supply to the motor by means of the main holding contactor and prevent mechanical fractures in the production process.
For more information contact NewElec, 086 010 3041, [email protected], www.newelec.co.za
Further reading:
Innovative sealing and bearing solution for pulp machine
SKF South Africa
Shaft power components
A leading South African manufacturer of paper-making equipment sought to modify an existing pulp machine and turned to trusted partner SKF to assist with the redesign of a critical sealing arrangement.
Read more...
Polymer bearings for maintenance-free bottling system
igus
Shaft power components
A favourite South African beer which is to be found on many a beer connoisseur’s table is being brewed in Belgium with the assistance of lubricant-free polymer bearings that will not contaminate the beer.
Read more...
Flexible, lightweight disc couplings for advanced industrial performance
Bearing Man Group T/A BMG
Shaft power components
BMG has expanded its extensive portfolio of quality branded couplings with the introduction of the ESCODISC FIL series, a new generation of flexible, lightweight disc couplings.
Read more...
Industrial valve solutions
Bearing Man Group T/A BMG
Shaft power components
BMG’s Fluid Technology division supplies and supports an extensive range of components for fluid technology systems. These include valves, hydraulic hoses and fittings, accumulators, cylinders, heat exchangers, hydraulic motors and hydraulic plumbing, as well as pumps and reservoir accessories.
Read more...
Direct-controlled seat valve
Shaft power components
A new direct-controlled seat valve enables storage-free, load-tight holding functions in dynamic linear units without an additional control pressure supply, and offers significant advantages over classic, pilot-controlled solutions, particularly in stationary and servo hydraulics.
Read more...
Wind energy in the Black Forest
Shaft power components
For more than 20 years, numerous wind turbines have stood in the Black Forest and are now receiving a performance boost through repowering projects.
Read more...
The advantages of using an adjustable cable gland
Shaft power components
Pratley continues to demonstrate its engineering leadership with its innovative adjustable cable gland, designed to significantly reduce maintenance and labour costs across a wide range of industrial applications.
Read more...
Advanced tensioning solutions for industrial applications
Shaft power components
OST-Africa has developed an advanced range of tensioning elements, designed to meet the demands of mechanical power transmission
Read more...
Single DDI cable solution simplifies connectivity
SEW-EURODRIVE
Shaft power components
Cabling can be one of the most challenging aspects of automation and drive system installations, often leading to delays, faults and inefficiencies. SEW-EURODRIVE offers a solution that simplifies connectivity, its innovative Digital Data Interface technology combined with a single cable system.
Read more...
The critical role of check valves
Parker Hannifin - Sales Company South Africa
Shaft power components
In fluid power systems, the performance and reliability of the entire operation often hinge on components that are small in size but significant in function. Among these, the check valve stands out as a fundamental yet frequently overlooked element.
Read more...
printer friendly version