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Large Solid-Core Design Makes Monitoring Larger Circuits Easy

Ground Fault Detection at Docks and for Other Large Equipment Using High Current Circuits

Since the early 1980’s, NK Technologies has been designing and manufacturing ground fault sensors for industrial and commercial applications. These applications include protecting heat trace and snow melt cable, submersible pumps, water features, pools and many electrical heating applications.

In the early 2000’s, NK Technologies’ engineers designed a larger sensor with the capacity to monitor circuits up to around 300 amps. For applications drawing more current or using conductors that are larger than would fit through the sensing window, an external “zero sequence” current transformer was needed; the fault would be expressed at 10% of the actual fault current. To increase the amount of current through the sensor, the CT secondary is looped two or three times through the sensing aperture to get the current up to a detectable level. This approach is not very attractive, even to those who frequently install electrical equipment in less than ideal conditions. Now the design engineers at NK have developed a sensor with an aperture measuring four inches in diameter. This allows conductors carrying 800 amps or more to pass through easily.

The National Electric Code 2011 added section 555.3 to require ground
fault circuit protection for all circuits feeding a dock. The trip point was
specified to be 100 mA. The 2017 Edition reduced that trip point to 30 mA.
Not all jurisdictions have accepted this lower detection level, but they may
in the future. The smaller NK Technologies’ sensors can be used to monitor
individual circuits to each slip at a dock, with the sensor output energizing a shunt trip breaker operating mechanism circuit. The entire feed can be used to monitor the main feeding circuit to the pedestals, to again complete the circuit to operate a shunt trip breaker.

Docks and marinas are not the only place where higher current circuits should be protected with ground fault detection sensors. Adding ground fault protection to amusement park rides, whether permanently installed or temporary, should be considered even in places where it is not specifically required under NEC section 525 or 518. The last thing anyone would want is to be shocked while taking the newest roller coaster at their favorite park.

Another place where there is a need for larger ground fault sensors is on chair lifts at ski resorts. The motors and lighting required by this equipment draw considerable amounts of power and there is always a chance of dangerous conditions when the environment is wet and the skier’s clothing is soaked. Whether controlling a contactor or a shunt trip breaker, ground fault sensors from NK Technologies are the first choice by experienced personnel and designers.

AG-LC Ground Fault Sensors for Monitoring

Higher Current Circuits

AG-LC series ground fault sensors are the latest design innovation from NK Technologies. The NEC added section 555.3 to require ground fault protection of the main over current device feeding marinas and boat yards. These services are often carrying up to 800 amps; most sensor designs will not allow the conductors to pass through a single sensing ring.

By designing a sensor in a large solid-core housing, the conductors will not have to be passed through a separate sensing device like a zero sequence current transformer. This design makes monitoring of larger circuits a breeze, whether to protect boaters, or large equipment like amusement park rides or gantry cranes.

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ATS Series with Digital Display Setpoint

 

ats-digital

ATS Series AC Current Sensors combine a current operated switch and transducer into a single package. The FL model features a digital display that gives visual indication of the setpoint for greater accuracy. The sensor provides a solid- state contact which will change state when the current exceeds an adjustable level or falls below the normal running current. This means reduced installation time, plus the option to have local control of a starter coil while at the same time sending the analog signal back to a controller housed in a separate cabinet.

View Manual – ats-series-with-digital-display-setpoint

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Daz & Baz

Back by popular demand.  A Cane Toads View of Life!

Storyline

This is the story of a toad named Baz, who has suddenly, for no good reason which is apparent, disappears. As Baz is gone, the story of the theories put forth to his possible plight is told by his friend Daz, whose “mates call him Dazza” and who tells the story as he thinks it went. Daz tells the audience that he knows not where Daz went, only that he disappeared “like a fart in a fan factory” and that since he’s disappeared, nobody around knows what happened to him. In this short film, Daz tells us his theories on what may have happened…

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Bicycle Dreams

Synopsis:

They are seekers, madmen, and angels hell-bent on riding across America on a bicycle in less than ten days. But what begins as the adventure of a lifetime is transformed in an instant when tragedy strikes the race. These voyagers discover what is truly at stake as they pedal on, praying for the deliverance only the finish line can bring. By journey’s end, some are saved, others are lost, but all learn that the fuel that takes a soul toward its own true destiny is desire.

About the Race:

The Race Across America is an epic, 3000-mile bicycle race from the Pacific to the Atlantic. First held in 1982, RAAM is considered the most challenging sporting event in the world. Top riders finish in under 10 days, riding over 300 miles per day and sleeping only a few hours per night. Amid the sleepless grind, riders must endure the searing heat of the Mojave Desert, the agonizing climbs and descents of the Rockies, the driving winds of the Great Plains, and the twisting switchbacks of the Appalachians before the final sprint to the finish line in Atlantic City. With little prize money at stake, the fundamental goal of the race is simply to finish, a challenge half of all riders fail to meet.

About the Production:

Filmmaker Stephen Auerbach and his crew worked around the clock to capture the highs and lows of the Race Across America. With 18 cameras in the field, the team found innovative ways to document this massive event. To uncover the inner workings of the race, embedded camera operators traveled inside the riders’ crew vehicles, gaining unprecedented access to the cyclists and their teams. Their footage captured emotional and physical breakdowns, late-night strategy sessions, and great moments of personal triumph, all in intimate detail. Auerbach then took on the enormous task of editing hundreds of hours of material into a powerful, inspiring look inside the most difficult race on Earth.

Great Documentary, view Trailer.

Winner of 5 raams, including 2010, Jure Robic was killed in a traffic accident on a forest road near his home. May he rest in peace.