Electricity + Control April 2017

DRIVES, MOTORS + SWITCHGEAR T AN FORMERS + SUBS ATIONS

ROUND UP

Dc voltage transducers

Switchgear assemblies for Liqhobong JB Switchgear was awarded a contract by projects company DRA Global for the design, manufacturing and supply to the Liqhobong DiamondMine in Lesotho for a comprehensive range of low voltage switchgear assemblies which included containerisedmotor control centres, outdoor kiosks, distribution boards, PLC panels, remote I/O boxes, field isolators and junction boxes. In addition to this, JBSS supplied a large number of variable speed drives and soft starters. Some of the motor control centres were skid-mounted to facilitate mobility on the mine site. The electrical equipment was supplied by Rockwell Automation, and the communication protocol was Ethernet. Starter sizes range from 0,55 kW up to 220 kW, with an operational voltage of 525 V, and a fault level of 50 kA.

VTD-BD Series voltage trans- ducers (from NK Technolo- gies) are high-performance transducers for sensing volt- age in dc powered installa- tions. Applicable for use on circuits to 600 Vdc, VTD-BD voltage transducers provide

a fully isolated +/-5 Vdc or +/-10 Vdc output signal in response to dc voltages that change polarity. Housed in an easy-to-install DIN rail or panel mount case, the VTD-BD Series comes in a variety of ranges to suit many primary voltages. Voltage transducer applications Voltage Monitoring • Detect below normal or ‘brown out’ voltage condi- tions protect against possible motor overheating • Identify conductor loss conditions by detecting volt- age reduction in one motor lead • Monitor over voltage conditions associated with regenerative voltage to help in diagnosing/avoiding motor drive issues • Detect voltage conditions that may cause stress in or damage to soft starter components (SCRs) Enquiries: Denver Technical Products.Tel. +27 (0) 11 626- 2023 or email denvertech@pixie.co.za

MD, Johan Basson says the manufacturing pro- gramme is now nearing completion, and praised the DRA project team for the way this multimillion Rand project was handled. Likewise, he added that the Liqhobong teamwere also on top of their game, and that it was another good project for JBSS. The company supplied their highly-regarded and popular ‘Eagle Series’ of motor control centres. This design carries comprehensive type test cer- tification for compliance with IEC 61439-2 and IEC TR 61641. Basson says that around 31 000 tiers of this robust and user-friendly design has been sup- plied to destinations throughout Africa and abroad. Enquiries: Email johanb@jbswitchgear.co.za

April ‘17 Electricity+Control

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