1. POWER QUALITY

 Power quality refers to a wide variety of variations in the electric power supplied to utility customers.

If the power quality standards from the distributed resources do not meet regulations, both utilities and the customers might be penalized. This is because when the supply voltage is distorted, a device draws non-sinusoidal currents and can cause many technical problems such as overheating, malfunction, and premature aging. And the non-sinusoidal current also causes thermal and insulation stress on network devices, such as transformers and feeder cables.

Poor power quality ultimately results in financial losses caused by equipment downtime, increased maintenance activities, and shorter lifetimes and it is directly connected to wiring problems, grounding issues, switching transients, load variations, and harmonic.


Poor power quality ultimately results in financial losses caused by equipment downtime, increased maintenance activities, and shorter lifetimes and it is directly connected to wiring problems, grounding issues, switching transients, load variations, and harmonic.


In order to cope with and manage power quality, one must find a reliable monitoring and reporting method. Most utilities have adopted these power quality standards to develop and enforce regulations.


Some of the key standards created by industry are IEC 61000-4-30 Class A and Class S, IEC61000-4-7 harmonic measurements, and IEC61000-4-15 for flicker. Industry standards not only establish a common understanding of power quality in real-world electrical networks, but also give users confidence they will have accurate data to solve problems and issues related to events. These are essential in heavy current measurement as they offer reliability, accuracy, and the guarantee of extended service life.


In electrical networks, voltage sags, swells, flickers, variation in nominal ratings, and distortion due to harmonics all contain the key information regarding the electrical health of the network.


Therefore, the accuracy of current measurement is highly related to power quality, and the current measurement accuracy is the key to providing reliable and repeatable results.


At this time, the demand of wide frequency range, revenue-grade current transformers to revenue-grade metering requiring high accuracy measurement is growing because it is important to enhance network power quality for the reliable results.


There are three types of power quality meters: self-contained (direct drive), current transformer rated (1A:5A) and external current transformers(333mV:100mA).


 J&D offers full feature power quality solutions including the Revenue-Grade CTs.


※ J&D Power Quality Partners

1. EDMI Mk11 (Revenue Grade + Power Quality Class A)

2. CTLab VectoIII (Cloud based + Power Quality Class A + up to 9kHz harmonic)

3. Powerside PQube® 3 (Revenue Grade + Power Quality Class A)

4. Iskra iMC785 (Power Quality Class A)

5. J&D JAGUAR6300 (Power Quality Class S)


2. AC metering

There are three types of electric smart meters: self-contained (direct drive) and current transformer rated(1A:5A) and external current transformers(333mV:100mA).


Most Revenue-grade smart meters used on homes or commercial building are self-contained. Power meter and Multi-circuit energy monitoring to improve power distribution efficiency uses current transformer rated or external current transformer.


The majority of energy efficiency applications are undertaken with the goal of resource conservation, climate protection, and most commonly cost savings. Energy efficiency is about providing a better understanding of how and where energy is being consumed and using this data to make effective adjustments to energy consumption. By adopting more efficient technology or production processes a greater level of energy efficiency can be attained. Auditing the energy efficiency in a home/building before and after these upgrades is key to verifying performance improvements.


J&D offers a variety of power energy meters, remote CTs that is capable of tracking energy consumption in both residential and commercial applications. Visit the application products information below for more information on J&D’s line of current transformers and energy efficiency meters.




How to choose the right current transformers for Power Quality & AC metering? 

First, rank the important factors.

– Rigid: Solid core can be your solution but for the solid core, conductor must be inserted through window.

With the solid core, you must disconnect the conductor to feed it through the window opening of the DC CT.


– Compact and Light-weight: Split core can be your solution.


– When space is limited or the conductors’ shapes are odd, then Rogowski split core would be the solution.

Split core, and Rogowski coil CTs are designed to be easily installed without disconnecting any wires.


– What the meters require: With so meters many variables, it is sometimes difficult to choose exactly the right current transformers for a power monitoring project. Various meter models require checking and selecting the output and accuracy of the current transformers. Some ways meter choice impacts CT choice.

CT outputs – Which input is your meter designed for? Voltage or Ampere?

– Common industry standards are 333mV, 100mA and 1A, or 5A.

Does the meter have the ability to work with flexible Rogowski coils either by themselves or with an amplifier/integrator?

– Common industry standards are integrator output: 333mV, 100mA and 1A, or 5A.

Do you require a Revenue-grade CTs?

– The standard Revenue-grade CT meets IEEE C57.13 Class 0.6 and 0.3 standard and IEC61869-2 Class 0.5S and 0.2S standard. Revenue-grade current transformers in thinking about your project type and goals, it is important to keep in mind what the end-data will be used for. If you are using a Revenue-grade meter for tenant submetering or billing purposes, every bit of accuracy count, and a Revenue-grade CT would be ideal.

Do you require a power quality monitoring CT?

– Maintaining compliance with IEC61000-4-30 standards is the most important thing, especially with power quality monitoring equipment. High specification line of flexible current transformers that measures AC current for power metering, power quality analysis use. The wide frequency range CT represents an excellent choice for harmonics and power quality.


Do you have CT’s safety certification?

– Maintaining compliance with UL61010-1 standards is paramount, especially with energy monitoring equipment. If you currently use CTs or anticipate using them in the future, keep UL61010-1 or UL 2808 in mind. CTs with the UL61010-1 and UL2808 certification make operating power meters safer, particularly those for commercial submetering.


3. DC metering

There are two types of DC smart meters: self-contained(Direct drive) and external DC Voltage & DC current transducers.


Some of the greatest demand for DC metering has been found in renewable energy applications like solar energy panels metering, ESS, electric vehicle charging stations and more.


Monitoring these applications allows for energy production & tracking amount lost before conversion and measuring efficiencies and tracking performance.


J&D offers full feature DC metering solutions including the remote DC Current and DC Voltage transducers.


J&D CT – IDCS series


※ J&D DC Metering Partners

1. EMH Metering EM4TII

2. Accuenergy AcuDC240 Series

3. eGauge Systems JAGUAR IoT(15Channel, 30Channel)

4. Powerside PQube® 3 

5. KMB SMY134

How to choose the right current transducers for DC metering?

First, rank the important factors.

– rigid: Solid core can be your solution but for the solid core, conductor must be inserted through window

With the solid core, you must disconnect the conductor to feed it through the window opening of the DC CT.


– Compact and Light-weight: Split core can be your solution.

Split core DC CTs are designed to be easily installed without disconnecting any wires.


– What the meters require: With so meters many variables, it is sometimes difficult to choose exactly the right

 DC current transducers for a DC power monitoring project. Various meter models require checking and selecting the output and accuracy of the DC current transducers. Some ways meter choice impacts DC CT choice.

DC CT outputs – Which input is your meter designed for? Voltage or Ampere?

– Common industry standards are 471mVdc, 4Vdc and 100mAdc.

3) Do you require a Revenue-grade DC CT?


– Some of the greatest demand for DC static meter(IEC 62053-41 ED1) has been found in renewable energy applications like solar energy panels metering, ESS(Energy Storage Systems), Electric Vehicle charging stations and more.

Do you have DC CT’s safety certification?

– Maintaining compliance with UL61010-1 standards is paramount, especially with DC energy monitoring equipment. If you currently use DC CTs or anticipate using them in the future, keep UL61010-1. DC CTs with the UL61010-1 certification make operating DC power meters safer, particularly those for DC submetering.