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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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NEW – Dew point Transmitter – DP Series

Dew point

Dew point (Td) – is increasingly being used as a moisture measurement & control parameter for two reasons:

1/ Dew Point is a direct measure of only the moisture content in the air, unlike the measure of relative humidity that is a hybrid measurement of temperature and moisture.

2/ The dew point is an accurate predictive value that indicates the temperature at which moisture will condense out of the air. Liquid moisture condensing on surfaces can cause staining, creates a ideal environment for mold growth and left unabated can result in structural deterioration of many building components.

Moisture control in buildings is becoming a critical issue particularly when buildings are becoming more energy efficient by adding insulation, utilizing thermal pane windows and utilizing much more efficient cooling equipment. All of these initiatives reduce the sensible load (dry bulb) in buildings meaning that cooling equipment runs for shorter periods of time to cool the space to the target temperature.

At the same time, moisture loads (or latent loads) in the space contributed by outside air ventilation, people and some indoor activities have not been affected by these energy initiatives. As air conditioners run less frequently, the ability to remove and control moisture in the space is also diminished. In many buildings we are at the point where we cannot depend on temperature sensing to control moisture. It is now necessary to separately measure moisture and in some cases employ specific dehumidification strategies to control it.

Precision Dewpoint Transmitters

It’s state-of-the-art design combines digital linearization and temperature compensation with a highly accurate and reliable thermoset polymer based capacitance humidity sensor and curve-matched NTC thermistor temperature sensor for reliability and accuracy in the most critical applications.

Dewpoint Transmitters

The DEW POINT sensors are available in room, duct or outside mounting configurations to meet the widest range HVAC applications. The DP Series has four measurement variables which include dewpoint, dry-bulb temperature, wet-bulb temperature and enthalpy. Outputs are available by either an analog, BACnet® or Modbus signal to provide the most efficient monitoring and control solution.

Features:

  • Highly stable RH sensor element
  • Humidity range: 0-100%
  • Curve-matched NTC thermistor
  • 4 – User selectable measurement variables
  • LCD display
  • 3 Available analog outputs
  • BACnet or ModBus communication
  • AC/DC operation
  • Room Dew point
  • Duct Dew point
  • Outside Dew point

Related Dew Point Documents:

Brochure

Installation Analog Outputs

For more information of Industrial Sensors refer to SENSIT

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NEW – Clean Room Monitor – Series CR3

clean room monitor

What is a Clean Room Monitor ?

A Clean Room Monitor, monitors a confined space, such as pharmaceutical labs and hospital isolation units, where provisions are made to reduce the particulate contamination and control environmental parameters like humidity, temperature and pressure within specifed limits to achieve a controlled environment for sensitive processes. Generally, the environment is controlled through the controls of an HVAC system, however due to the sensitive nature of cleanroom activities, facility management teams are seeking a solution that enables them to monitor these spaces not only within the space but also remotely.

Description:

The CR3 Series Clean Room Monitor, was developed specifically to allow for monitoring of confined spaces with accuracy and reliability. The CR3 allows for either in-room or remote monitoring with three different models; integrated sensors, remote sensors or display only to suit a variety of installation needs. It features a flush fitting stainless-steel front plate that enables the user to wipe-down the unit when necessary.

The CR3 allows for more effcient measurement of three critical parameters; humidity, temperature and pressure, in one flush mount enclosure. It is equipped with sensors with best in class accuracies to match cleanroom requirements, and can communicate with the building automation system via Modbus, BACnet® or Analog outputs. It is powered by a standard 24 Vdc or 24 Vac power supply.

The CR3 features a visual display for each parameter with bright, easy-to-read LED’s, which enable users to view from long distances. Each parameter includes an alarm function with programmable setpoints for different application types, and provides both high and low alarm visual indication.

 

The CR3 is CE and RoHS compliant.

Clean Room Monitor Features:

• Humidity, Temperature & Pressure
• BACnet®, Modbus or Analog Outputs
• In-room or Remote Monitoring
• Individual alarms for ALL parameters
• Large Easy-To-Read Display

 

Clean Room Monitor Related Documents:

  Brochure:

 

For more information of Industrial Sensors refer to SENSIT

 

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Veeder Root-Meter Register

7887 Meter Register:
Designed for maximum readability – engineered for extra life in fuel deliveries and, fluid flow transactions of all kinds.
1. New crisp, high visibility digital display for optimum readability in all ambient lighting.
2. Latest technology, modern materials give maximum dependability at speeds to 250 rpm of right wheel.
3. Positive action knob reset.
4. Built-in precision totalizer accumulates up to 99,999,999 units.
5. Acetal resin components for smooth operation and extra long life.
6. Fits all popular flow meters.

Description:
The Meter Register is the outstanding choice for recording and displaying delivery data in a wide variety of industries. In the petroleum refining and distribution field, it is used from the well to pipelines and storage centers, then to gasoline and fuel oil delivery trucks. In the chemical processing field, it can be used for displaying totals during mixing and batching operations.

The 7887 Meter Register totalizes and displays high speed deliveries and transactions in large easy-to-read figures. Ideal for increased efficiency in all kinds of liquid inventory and delivery operations. Utilizing a geared drive available in a wide selection of ratios, the Meter Register records in practically any unit of liquid measure – gallons, liters, barrels, etc. – as well as non-liquid units.

Special optional adaptors are available to mate the Meter Register with all standard meters and pumps. It also easily combines with Veeder-Root Meter Preset and Printer to form a complete count, control and print system.

Finished in corrosion resistant epoxy, the sturdy housing protects the Meter Register in demanding environments and extremes in weather.

Example: Veeder-Root 7887 Meter Register & 7889 Preset fitted to TCS-700 Series Flowmeter.

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