Achieves both water resistance and small size with improved heat
dissipation-sealed enclosure and transmission line theory
KANAGAWA, Japan--(Business Wire)--
OKI Electric Cable (TOKYO:5815) today announced the development of the "eco
Surge U", an ultra-small surge suppressor*1, which is based on transmission line
theory*2. Applying this theory, OKI Electric Cable succeeded in making the size
of the suppressor remarkably small. In addition, with its original
water-resistant sealed enclosure, the "eco Surge U" can be installed both
indoors and outdoors. Sales of the product start September 2009.
"We are pleased to announce this new and ultra-small `eco Surge U` that can
offer users a surge suppression method at an affordable price by simply
connecting to a motor device. The suppressor can be used anywhere as it is
small, water-resistant and can be attached to new devices as well as existing
systems," said Takashi Hattori, President of OKI Electric Cable. "Leveraging
these characteristics, we will offer this suppressor to industrial equipment
fields that use inverter-fed motors."
Compared to conventional filters for 15kW-motors, the "eco Surge U" is smaller
and lighter (one-fifth the weight and one-fourth the size) and can be used from
0.2kW up to 75kW motors. The newly developed original sealed enclosure with
improved heat dissipation efficiency *3(on the control unit) enabled OKI
Electric Cable to develop a surge suppressor that is water-resistant, a feature
not available in conventional filters, and that is suitable for outdoor use.
The speed of inverter switching is becoming faster these days. In addition, by
applying higher voltage to improve power efficiency, micro-surge, which is
induced by impedance*4 mismatch of motor cable and the motor, also increases.
This can cause malfunctions in the motors. Such effects include insulation
deterioration in motor coils, which damages the motor.
As micro-surge countermeasures, conventionally, LC filter circuits had been
inserted between the inverter and motor to slow down the surge rise on drive
signal waveforms and dissipate the surge energy as heat. However, with this
method, as the motor power increased, it was necessary to use expensive and
large-sized high-power-rated capacitors and coils. Thus, the space requirement,
price and increased power consumption for suppression had been problems.
While the conventional measure requires wiring to insert the filter between the
inverter and the motor, the new "eco Surge U" is directly connected to the motor
terminals.
OKI Electric Cable will showcase this suppressor at Electrical Construction
Equipment and Materials Fair 2009, which will be held from May 27-29 at Tokyo
Big Site in Japan. (Booth number: 1-41 one hall in the west)
[Glossary]
*1 Surge suppressor
This is a surge suppressor cable that uses a special conductor and insulator and
employs transmission line theory. This method can absorb and attenuate the surge
as well as reduce the reflection in surge suppression wire
*2 Transmission line theory:
This is a theory that the characteristic of transmission lines (i.e. cables and
wires) change depending on the frequency applied. The following two principles
are included in the surge control function:
- The higher the frequency, the more likely the signal current will run on the
surface of the conductor (skin effect)
- The lower the frequency, the larger the cable impedance is for the
transmission line (i.e. cables and wires), and conversely, the higher the
frequency, the smaller the impedance, and eventually, changes in impedance
become flat.
*3 Sealed enclosure with improved heat dissipation efficiency
A joint patent with Fuji Electric Systems Co., Ltd is currently pending for this
structure.
*4 Impedance:
This is the amount of electrical resistance for AC signal. The impedance value
is determined from R (resistance), L (inductance) and C (capacitance).
About Oki Electric Cable Co., Ltd.
Established in 1936, Oki Electric Cable Co., Ltd. provides various advanced
communications cables, optical cables, and related electronic parts and
equipment to the worldwide market. As a member of the OKI Group, Oki Electric
Cable Co., Ltd. plays a major role in the group, with the website at
http://www.okidensen.co.jp/english/e_home.htm
Notes:
* eco Surge is a trademark of Oki Electric Cable Co., Ltd.
* Names of companies and products are trademarks or registered trademarks of the
respective companies and organizations.
Oki Electric Cable Co., Ltd.
Jun Hara, +81-44-754-4369
Corporate Planning Office
Contact Form: https://www.oki.com/ssl/oec/contact/english
Copyright Business Wire 2009
