Electricity + Control March 2015

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Earth leakage protection with
harmonic filtering
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
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-
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
ROUND UP DRIVES, MOTORS + SWITCHGEAR
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