VFD and SCR output waveforms are rough approximations of a sine wave. There are numerous spikes and dips in each cycle. ATR transducers use a mathematical algorithm called "True RMS," which integrates the actual waveform over time. The output is the amperage component of the true power (heating value) of the AC current waveform. True RMS is the only way to accurately measure distorted AC waveforms. Select ATR transducers for nonlinear loads or in "noisy" power environments.

The current waveform of a typical linear load is a pure sine wave. AT transducers measure the peaks of these sine waves, then calculate the average amperage. This works well on constant speed linear loads in a "clean" power environment. Select AT transducers for strictly linear loads on "clean" power.

ATR Series

‘ATR’ transducers from NK Technologies combine a current transformer and a True RMS signal conditioner into a single package. The ATR Series provides True RMS output on distorted waveforms found on VFD or SCR outputs and on linear loads in "noisy" power environments. Available in a solid or split core case.

Applications

• VFD Controlled Loads
  VFD output indicates how the motor and attached load are operating.
• SCR Controlled Loads
  Accurate measurement of phase angle fired or burst fired (time proportioned) SCRs. Current measurement gives faster response than temperature measurement.
• Switching Power Supplies and Electronic Ballasts
  True RMS sensing is the most accurate way to measure power supply or ballast input power.

Features

• True RMS Output
  — True RMS technology is accurate on distorted waveforms like VFD or SCR outputs.
• Jumper Selectable Ranges
  — Reduces inventory.
  — Eliminates zero and span pots.
• Isolation
  — Output is magnetically isolated from the input for safety.
  — Eliminates insertion loss (voltage drop).
•  UL, CUL and CE Approval
  Accepted worldwide.

Specifications

Output Signal	4–20mA, Loop-powered, True RMS
Output Limit	23mA
Accuracy	1.0% FS
Response Time	600mS (to 90% step change)
Frequency Range	10–400Hz
Power Supply	24VDC Nominal, 40VDC Maximum
Isolation Voltage	UL listed to 1,270VAC, tested to 5KV
Input Ranges	Field selectable from 0–200A (see Ordering Information). Consult factory for custom ranges.
Sensing Aperture	• FT Models: 0.75" (19mm) dia. • SP Models: 0.85" (21.5mm) sq.
Case	UL 94V-0 Flammability rated
Environmental	–4 to 122°F (–20 to 50°C), 0–95% RH, non-condensing
Listings	UL 508 Industrial Control Equipment (USA & Canada), CE (Pending)

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AT Series

‘AT’ Current Transducers from NK Technologies combine a current transformer and signal conditioner into a single package. The AT Series has jumper selected current input ranges and industry standard 4–20mA, 0–5VDC or 0-10VDC outputs. The AT Series is designed for application on ‘linear’ or sinusoidal AC loads. Available in a split core case or two types of solid core cases.

• Automation Systems
  Analog current reading for remote monitoring and software alarms.
• Data Loggers
  Self-powered transducer does not drain data logger batteries.
• Panel Meters
  Simple connection displays power consumption.

Features

• Accurate
  Factory matched and calibrated single piece transducer is more accurate than traditional two-piece field installed solutions.
• Average Responding
  "Average responding" algorithm gives a RMS output on pure sine waves. Perfect for constant speed (linear) loads.
• Jumper Selectable Ranges
  — Reduces inventory.
  — Eliminates zero and span pots.
• Isolation
  — Output is magnetically isolated from the input for safety.
  — Eliminates insertion loss (voltage drop).
• UL, CUL and CE Approval
  Accepted worldwide.

Specifications

	–005 Models	–010 Models	–420 Models
Output Signal	0–5VDC	0–10VDC	4–20mA
Output Limit	8.2VDC	15VDC	32mA
Accuracy	1.0% FS	1.0% FS	1.0% FS
Response Time (10–90% step change)	100mS	100mS	300mS
Frequency Range	50–60Hz	50–60Hz	20–100Hz*
Other Frequencies	Special calibration available for any frequency from 10–400Hz*
Power Supply	Self-powered	Self-powered	12–40VDC, Loop-powered
Loading	1M W minimum for rated accuracy 100K W add 1.3% error		See "Power Supply" below
Isolation Voltage	UL listed to 1,270VAC, tested to 5KV
Input Ranges	Field Selectable Ranges from 0–200A (see Ordering Information). Custom ranges available, consult factory.
Sensing Aperture	• FF Case: 0.55" (14mm) dia. • FT Case: 0.75" (19mm) dia. • SP Case: 0.85" (21.5mm) sq.
Case	UL 94V-0 flammability rated
Environmental	–4 to 122°F (–20 to 50°C), 0–95% RH, non-condensing
Listings	UL 508 Industrial Control Equipment (USA & Canada), CE

*For sinusoidal waveforms only. Select ATR Transducers for distorted waveforms.

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AT/ATR 3 & 4 Series

'AT/ATR 3 & 4' transducers from NK Technologies combine a high capacity current transformer and a signal conditioner into a single package. The AT version is Average Responding for use on linear (sinusoidal) loads. The ATR version is True RMS for use on distorted waveforms found in VFD or SCR outputs. Available in a solid or split core case.

Applications

• Large Pumps
  Detect dry run electronically.
• Power Generation
  Measure the output of generators.
• Electric Heating Elements
  — Monitors heater load.
  — Faster response than temperature sensors.

Features

• Large Aperture
  Accommodates large conductors or wire bundles.
• Select the Right Output
  — True RMS technology is accurate on distorted waveforms like VFD or SCR outputs.
  — Average Responding-for linear, sinusoidal waveforms
• Three Switch Selectable Ranges
  — Reduces inventory.
  — Eliminates zero and span pots.
• Isolation
  Magnetic isolation protects installers and systems.
• Easy Installation
  Single piece with integral mounting brackets makes for a simple, solid installation.
• UL, CUL and CE Approval
  Accepted worldwide.

Specifications

Output Signal	4-20mA, Loop-powered
Output Limit	23mA
Accuracy	1.0% FS accuracy, True RMS
Measurement	True RMS or Average Responding (see Ordering Information)
Response Time	500mS (to 90% of step change)
Frequency Range	• ATR: 10-400Hz • AT: 50-60Hz, Sinusoidal
Power Supply	24VDC Nominal; 40VDC Maximum
Isolation Voltage	600VAC
Input Ranges	• AT/ATR3: 375, 500, 750A • AT/ATR4: 1000, 1333, 2000A
Sensing Aperture	3.0" (76mm) dia.
Case	UL 94 Flammability rated
Environmental	-4 to 122°F (-20 to 50°C), 0-95% RH, non-condensing
Listings	UL 508 Industrial Control Equipment (USA & Canada), CE

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ATP Series

‘ATP’ Current Transducers from NK Technologies are a new variation of our tried and true transducers. Self-powered sensors are the easiest to install, but producing the industry standard 4 to 20 mA output requires a separate power source, so there will be 4 mA when there is zero current. The ATP Series allows the installer to use 120 VAC to power the sensor, with other models configured to use 24 VAC or VDC. NK can provide models producing industry standard 4–20mA, 0–5VDC or 0-10VDC outputs. The response times are faster and accuracy higher than our self-powered models. All have the jumper or switch (high current models) to select the range closest to the actual load, providing for the best resolution.

• Automation Systems
  Analog current reading for remote monitoring and software alarms.
• Data Loggers
  Self-powered transducer does not drain data logger batteries.
• Panel Meters
  Simple connection displays power consumption.

Features

• Accurate
  Solid core models 1.0% FS, and
• Average Responding
  "Average responding" algorithm gives a RMS output on pure sine waves. Perfect for constant speed (linear) loads.
• True RMS
  —Available from models with ranges 0-375 amps and higher
• Jumper Selectable Ranges
  — Reduces inventory.
  — Eliminates zero and span pots.
• Isolation
  — Output is magnetically isolated from the input for safety.
  — Eliminates insertion loss (voltage drop).
• UL, CUL and CE Approval
  Accepted worldwide.

Specifications

	–005 Models	–010 Models	–420 Models
Output Signal	0–5VDC	0–10VDC	4–20mA
Output Limit	5.6 VDC	11.2 VDC	22.4 mA
Accuracy (Split Core)	1.0% FS	1.0% FS	1.0% FS
Accuracy (Solid Core)	0.5% FS	0.5% FS	0.5% FS
Accuracy (Large Case)	1.0% FS	1.0% FS	1.0% FS
Response Time (10–90% step change)	100mS	100mS	100mS
Frequency Range	40–100Hz*	40–100Hz*	40–100Hz*
Other Frequencies	Special calibration available for any frequency from 10–400Hz
Power Supply      (2VA max)	120VAC or 24VAC/DC	120VAC or 24VAC/DC	120VAC or 24VAC/DC
Loading	25K W minimum for rated accuracy		500 W maximum
Isolation Voltage	Tested to 5KV
Input Ranges	Field Selectable Ranges from 0–2000A (see Ordering Information). Custom ranges available, consult factory.
Sensing Aperture	• FF Case: 0.55" (14mm) dia. • FL Case: 3.00"(76.2mm) dia. • SP Case: 0.85" (21.5mm) sq.
Case	UL 94V-0 flammability rated
Environmental	–4 to 122°F (–20 to 50°C), 0–95% RH, non-condensing
Listings	UL 508 Industrial Control Equipment (USA & Canada), CE (pending)

*For sinusoidal waveforms only. Select ATPR Transducers for distorted waveforms.

DT Series

'DT' Current Transducers from NK Technologies combine a Hall effect sensor and signal conditioner into a single package. The DT Series has jumper selectable current input ranges and industry standard 0-20mA, 4-20mA, 0-3VDC, 0-5VDC or 0-10VDC outputs. Available in a split core package.

Applications

• Battery Banks
  — Monitors load current.
  — Monitors charging current.
  — Verifies operation.
• Transportation
  Measures traction power or auxiliary loads.
• Electric Heating Elements
  Faster response than temperature sensors.

• Three Jumper Selectable Ranges
  — Reduces inventory.
  — Eliminates zero and span pots.
• Isolation
  — Output is magnetically isolated from the input for safety.
  — Eliminates insertion loss (voltage drop).
• Internal Power Regulation
  — Works well, even with unregulated power.
  — Cuts installation costs.
• Easy Installation
  Split core design with built-in mounting brackets makes installation a snap.

Specifications

Output Signal	0-20mA, 4-20mA, 0-3VDC, 0-5VDC or 0-10VDC
Output Limit	• 0–20mA, 4–20mA: 23mA • 0–3VDC: 3.5VDC • 0–5VDC: 5.75VDC • 0–10VDC: 11.5VDC
Accuracy	2.0% FS split core, 1% FS solid core
Repeatability	1.0% FS
Response Time	100mS (to 90% of step change) Split Core 20mS (to 90% of step change) Solid Core
Frequency Range	DC
Power Supply	20–50VDC, 22–38VAC. Power input and output signal are not isolated. 120VAC available in solid core designs only (maximum range 200 A)
Power Consumption	2VA
Loading	• 0–20mA, 4–20mA: 500 W maximum • 0–3/5/10VDC: 25K W for rated accuracy
Isolation Voltage	3kV (monitored line to output)
Linearity	0.75% FS
Current Ranges	Field Selectable Ranges from 0–400A (see Ordering Information)
Sensing Aperture	0.85" (21.5mm) sq. split core, 0.75" (19.1mm) solid core
Case	UL 94V-0 Flammability rated
Environmental	–4 to 122°F (–20 to 50°C), 0–95% RH, non-condensing

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