Basic HTML Version
Electrical protection and safety
ROUND UP
M
EANWELL
has introduced 25 W/35 W rectangular economical
plastic case LED power supplies – the APV/APC-25/35 series.
Following the same design concept of the APV series with CV mode,
and the APC series with CC mode, the new series has a non-PFC de-
sign, with the purpose of keeping the low-cost advantage as well as
being able to provide users with more alternatives while designing
the lighting fixtures.
With up to date high frequency switching topology, the APV/APC-
25/35 series features 90 – 264 Vac input range with up to 84% high
efficiency, making it possible for them to work between 30 and 70˚C
with free air convection. APV/C-25s (25W) are not potted whileAPV/C-
35s (35 W) are semi-potted for PCB protection. They provide basic
anti-moisture, anti-dust as well as heat-conduction features and have
the built-in standard functions, including short circuit, overload, over
voltage protection, withstand 300 Vac surge input for five seconds.
With an IP30 design, these new power units are recommended for
indoor LED lighting without the need for high level water- and dust-
proofing features. Typical applications include LED indoor lighting,
LED-based decorative lighting and LED electrical displays.
Enquiries: Ettienne van derWesthuyzen. Email ettienne@rectifier.co.za;
Ted Cheng. Email ted@meanwell.com.
New indoor LED power supplies
E
MIS Sales, part of the
Becker
mining group, commissioned New-
Elec to design a motor protection and control relay to meet the
needs for coal mining flameproof feeder gate-end boxes, as well as
flitting panel applications. The design criteria embraced all the con-
ventional motor protection, as well as earth leakage and short circuit
protection, and in addition, had to meet the following requirements.
The relay had to feature integrated selectable starter control for DOL
and reversing starters. It had to accommodate six preset settings for
different motor sizes, downloadable from the door- mounted MMI by
operational staff. Indication of the setting selection had to be displayed
to allow the supervisory staff tomonitor the relay. In addition, the relay
had to protect against contactor / vacuum failure or frozen contactor
conditions, protect and provide against earth insulation lock out, earth
leakage, and earth faults. Lastly, the relay was required to maintain a
nonvolatile date and time stamped 1 700 event and 50 fault record with
a download facility into Excel with drive and panel identification via an
IRDA link and an IS approved uploading and downloading handheld
MMI. These challenges were fully met with the launch of the EMIS
ProLoc motor protection relay now available through EMIS Sales.
In brief, the Proloc relay provides protection against all the usual
electric motor winding failure causes but includes enhanced features
such as timers, latch circuit, back-spin timer, unauthorised current de-
tection, start stall detection using power factor measurements and dry
run/ load loss detection by a user-selected method (current or power
factor). Proloc also features priming time delay timers as well as starts
per hour / consecutive start attempt limitation, earth leakage and earth
fault detection and protection related to over / under voltage, phase
rotation and over/under frequency. Starter logic for DOL, and Star Delta
circuits – reversing and standard, are easily configured.The associated
software also permits customized user labeling of inputs and outputs for
clearer identification of faults and commissioning of motors in various
applications.Three logic function blocks are included each having up
to three variables and an interlink capability.The Proloc arrangement
accommodates four inputs and five programmable output contacts.
Enquiries: Luc Dutrieux.Tel. 012 327 1729 or email sales@newelec.co.za.
N
ewElec
’s EC/ED relay monitors the insu-
lation reliability of the motor windings
and feeder cables to earth while the motor
is standing.The main contactor is prevented
from closing into a circuit if the insulation
level to earth has deteriorated to an unac-
ceptable level.
Included in the protection package are the
relay, an 11-pin plug-in base for easy removal
and a three-phase choke.The product may be
used regardless of the starter configuration.
LEDs indicate healthy or faulty conditions.
The selected ‘lock out’ relay model deter-
mines the acceptable insulation level, while
the fusedmeasuring circuit protects the relay
against inadvertent damage due to incorrect
connections. Compact in design, the EC/
ED is suitable for installation in flameproof
enclosures. The lock-out relay may be used
on both cables and motors starting DOL or
star delta. Simply pressing the ’start’ button
on a machine that has been standing for a
long period of time is risky and should be
avoided until the insulation level of themotor
has been found to be acceptable.
Enquiries: Luc Dutrieux.Tel. 012 327 1729 or
email sales@newelec.co.za.
New relay increases safety in mining
Relay monitors insulation reliability
31
September ‘12
Electricity+Control