Electricity + Control March 2015

DRIVES, MOTORS + SWITCHGEAR

ROUND UP

Earth leakage protection with harmonic filtering

Profibus accredited motor protection and control relay The NewCode motor protection and control relay from NewElec is fully Profibus accredited and retains the user-friendly features that are synonymous with the company’s products. Customers will ben- efit from theVectorial stall protection that allows the disengagement of the motor if a stall condition occurs on start-up, should there be no improvement in the power factor after 3 s.The relay provides pre- motor start insulation failure protection and power measurements that distinguish between real and apparent power consumption. NewCode’s load loss/ dry-run protection allows the user to decide if the load loss measurement will be done on current or power fac- tor measurements and accommodates the required priming time. Earth leakage protection is provided with user-selectable tripping curves and sensitivity levels and includes harmonics filtering.The onboard data base stores events and fault records and the continu-

NewElec ’s GA relay range eliminates concerns when protecting variable speed drives against earth leakage faults or down-grading earth leakage protection thresholds due to unease relating to nuisance trips on start-up. All GA relay models may be configured for either IDMT or instantaneous trip delay and include harmonic filtering. It is possible, for instance, to start a 250 kW motor by the direct-on-line method with a set 250 mA sensitive earth leakage trip threshold and not experience any nuisance trip whatsoever in the

process.This can be done even when the instantaneous trip selection has been selected. GA relays may be used to advan- tage when structured grading protection is required from the motor upstream in the distribu- tion feeding train, as a number of GA models starting at 30 mA upwards are available.The relay is not passive and will require a supply of either 110 or 220 Vac, ideally supplied from a source upstream of the main feeder. Enquiries: Email sales@newelec.co.za

ous coloured flash- ing LED provides a visual indication of the communications address. Control pan- el mounted display LEDs indicate the I/O status. Enquiries: Email sales@newelec.co.za

JB Switchgear Solutions supply a comprehensive range of high quality electrical assemblies which are compliant with relevant national and international standards. Safety, reliability and user- friendliness form an integral part of our product offer which includes: Ÿ Containerised and pre-fabricatedmodular substations. Ÿ Equipment for renewable energy projects. Ÿ Our EAGLE series of fixed and demountable Motor Control Centres Ÿ Rittal fixed, semi and full withdrawablemotor control centres. Ÿ Sabelco fixed, semi and fully withdrawable motor control centres. Ÿ VWE fixed and demountablemotor control centres. Solutions through focus and commitment.

Ÿ Floorstanding heavy duty distribution boards. Ÿ Distribution boards, kiosks and pillar boxes. Ÿ PLC andmarshalling panels. Ÿ VSD’s & soft starters. Ÿ Remote I/O boxes.

Ÿ 19” rack panels. Ÿ Control desks.

Ÿ Special enclosures. Ÿ Standard enclosures. Ÿ Custom control panels.

Ÿ Field Isolators & junction boxes. Ÿ Electrical spares & equipment.

8b Molecule Road, Vulcania Ext. 2 Brakpan. l Tel : +27 11 027 5804 l Fax: +27 11 813 1733 l Email: info@jbswitchgear.co.za l www.jbswitchgear.co.za

Electricity+Control March ‘15

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