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AMMJ Surge Protection Devices 21<br />
to the nominal voltage and other reflected waves. The SPD will aid in reducing the voltage peaks of the reflected<br />
waves. More importantly, if the connection between the drive and the motor extends outdoors, along a path that<br />
is exposed to the environment or close to the building’s steel structure, protection at this location is important to<br />
diminish the effects of direct lightning or induced voltage surges due to nearby lightning. These surges can cause<br />
damage to the drive, even if protection is provided at the motor input. At this location, a parallel connected, voltage<br />
responsive circuitry device is appropriate (one without frequency responsive circuitry). Frequency responsive<br />
circuitry is not recommended for this location due to the high harmonic content of the signal due to the normal<br />
operation of the drive. Installation of frequency responsive circuitry devices at this location will lead to failure of the<br />
SPD. Utilizing a voltage responsive circuitry device at this location will eliminate this possibility.<br />
5. Motor Input.<br />
Protecting the motor input is an essential step in protecting the drive system. Providing protection at this location<br />
prevents surge damage due to events propagated from the drive output to the motor input. Providing protection<br />
at this location aids in extending the life of the motor as the SPD helps to prevent damage to the windings and<br />
bearings of the motor due to surges. Further, if the connection between the drive and the motor extends outdoors,<br />
along a path that is exposed to the environment or close to the building’s steel structure, protection at this location<br />
is important to diminish the effects of direct lightning or induced voltage surges due to nearby lightning. These<br />
surges can cause damage to the motor, even if protection is provided at the drive output.At this location, a parallel<br />
connected, a voltage responsive circuitry device is appropriate (one without frequency responsive circuitry).<br />
Frequency responsive circuitry is not recommended for this location due to the high harmonic content of the signal<br />
due to the normal operation of the drive. Installation of frequency responsive circuitry devices at this location<br />
will lead to failure of the SPD. Utilizing a voltage responsive circuitry device at this location will eliminate this<br />
possibility.<br />
Overall, properly installed surge protective devices reduce the magnitude of random, high energy, short<br />
duration electrical power anomalies. These occurrences are typically caused by atmospheric phenomena<br />
(such as lightning strikes), utility switching, inductive loads, and internally generated overvoltages. The<br />
ultimate goal of our approach is to keep sites and systems operating safely and reliably. PowerTrip®<br />
Surge Protection Devices incorporate “Frequency Responsive Circuitry” technology years ahead of any<br />
other devices on the market today. Utilizing proprietary electro-chemical encapsulation, PowerTrip® SPDs<br />
dissipate large amounts of surge energy to prolong service life.<br />
Signing the order was easy...<br />
Greg wondered why he had taken so long to get outside assistance. Perhaps it was the fact that<br />
Maintenance consultants seemed to have a bad reputation – “Borrow your watch to tell you the time – then<br />
sell you your watch”. Perhaps it was because they had a reputation for charging exorbitant fees. Perhaps<br />
there was a little bit of pride involved – “It is my job to make this plant safe, efficient and reliable, and I am<br />
going to do it – myself!”<br />
But finally he had to admit that the challenges he faced were too great for any one person to deal with on<br />
their own, and he had contacted Assetivity. It’s amazing how a series of equipment failures (including a<br />
catastrophic conveyor pulley shaft failure that had caused a major safety incident and significant downtime)<br />
can focus the mind, he thought, wryly.<br />
At the initial meeting with the senior Assetivity consultant, Greg had been impressed by the way in which<br />
his problems and issues had been listened to, considered, and absorbed. He had liked the way that, in the<br />
course of their discussion, they had together been able to give focus to the complex network of issues and<br />
opportunities that he faced, and put these in perspective. He been attracted to the down-to-earth and<br />
practical discussion regarding implementation issues. And he was impressed by the focus on developing<br />
and implementing solutions, rather than on selling specific products, tools or methodologies.<br />
It had become clear, in the course of their discussion, that there was an urgent need to “get back to the<br />
basics” – to ensure that the current Preventive Maintenance program was appropriate, and was being properly executed at shop floor level, and that failures<br />
were being prevented, and the causes of those failures eliminated. They had agreed that the first step was to conduct a quick diagnostic review, focusing on<br />
these areas, in order to develop a plan of action. Getting authorisation from the Plant Manager had been surprisingly easy, and Greg was signing the Purchase<br />
Order for this review now. So far, it had been smooth sailing, but Greg knew that the real challenges lay ahead. But, with the involvement of Assetivity, he had<br />
confidence that they were on the right track.<br />
More than availability and reliability...<br />
Perth, Brisbane, Melbourne<br />
Ph +61 8 9474 4044<br />
www.assetivity.com.au<br />
Asset Management Consultants