Electricity + Control April 2017

37 / 48

ROUND UP DRIVES, MOTORS + SWITCHGEART AN FORMERS + SUBS ATIONS
Dc voltage transducers
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
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.
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
35 April ‘17 Electricity+Control