Unable to Recharge the prepaid meter

Solution: Connectivity Check: Confirm the meter is successfully communicating with the server. Serial Number Verification (SmartComm): Access the SmartComm Customer Master and ensure the serial number recorded matches the physical serial number of the connected meter. Duplicate Configuration Check: Verify that no two meters are incorrectly configured with the exact same serial number in the system.

Email Configuration SMTP Details Outlook

Solution: SMTP Host/Server Name: For Outlook.com: smtp-mail.outlook.com For Office 365/Microsoft 365: smtp.office365.com SMTP Port:587 (recommended) Encryption Method: STARTTLS Authentication: Your email account needs to be authenticated, so enable login or use the ""My outgoing server (SMTP) requires authentication"" option in your email client. Username: Your full Outlook email address (e.g., yourname@outlook.com or yourname@domain.com) Password: Blank

Email Configuration App Password creation for Gmail account

Reason - Gmail will work only with a secure encrypted app password Solution: Go to your Google Account settings. Navigate to the Security tab. If you don't have it enabled, turn on Two-Step Verification. Find and click on App passwords. Select an app name (like ""SMTP"" or ""Mail Client"") and click Generate. Copy the generated 16-character password and use it in your mail client's password field instead of your main Gmail password.

Email Configuration SMTP Details Gmail

Solution: Gmail SMTP Settings SMTP Server: smtp.gmail.com Port: 587: (requires STARTTLS/TLS) 465: (requires SSL) Authentication: Required Username: Your full Gmail address (e.g., user@gmail.com) Password: An App Password generated from your Google Account security settings Security/Connection: TLS or SSL, depending on the port chosen

Transfer existing sensor to a different gateway

Reason - Loss of old data stored under device id created Solution: To prevent data loss, edit the sensor and use the "Move to Gateway" option to transfer the sensor to a different gateway.

Asset list is not available in the filter

Reason - The asset is not assigned to the organization Solution: Check the asset selection settings in organization settings

Reason - Sensor/gateway limit exceeded Solution: Check license information for sensor/gateway limit

Cannot change the ip address of gateway

Reason - The ip address should is not available Solution: 1. if company network is being used check the accesibility to access 2. check if set ip is with in subnet range 3. Check if Primary and Secondary DNS is correct as per network settings 4. Set the Default Gateway IP to match the router's IP or the company network's default gateway IP.

3rd part meter not communication

Reason - 1. Memory map configuration wrong 2. (10 power -4 )Conversion factor is not available in third party memory map configuration 3. Data on modscan and software is matching but not matching with meter display readings Solution: 1. Verify data via Modscan, check wiring, confirm the meter parameter's datatype/function code in the memory map, and ensure the gateway supports that parameter datatype. 2. Can be added from conversion factor available in Master settings

Could not download certificate

Reason - All mandatory fields are not saved in organisation info settings Solution: All details should be given in mandatory field of organisation settings

Current Transformer (CT) Selection Criteria

Input Line Chokes for VFD to optimise AHF Sizing

A Variable Frequency Drive is an electro-mechanical drive used to control the speed & torque of AC Motors by varying the input voltage & frequency of the motor. VFDs are widely used in conveyor systems, pumps, blowers, machine tools & other such applications which require variable speed along with variable torque. But a VFD, being a non-linear load, is a source of harmonics in the line.

Solutions for Harmonics Mitigation:

Active Harmonic Filters are the ideal solution for harmonic mitigation. They compensate the harmonics generated by VFD by generating the same harmonic components in the opposite phase. As a result, Power Factor can be maintained close to unity & the supply current will be a pure sinusoidal wave with no harmonic contents.

However, AHFs have a very high cost per ampere if they are used to compensate for the harmonics generated by the VFDs. The sizing of the AHF can be reduced by reducing the harmonic content at the output of the VFD.

Hence input line chokes are used at the output of the VFD. This is an inductor coil which opposes rapid change in current because of its impedance.

Input Line Chokes will:

Reduce AC input line harmonics
Help meet IEEE-519 limits
Increase impedance to voltage/current spikes
Prevent nuisance over-voltage tripping

Understanding Accuracy Classes:

Accuracy classes are typically 0.2, 0.2s 0.5, 0.5s, or 1.0, indicating very precise measurement at rated current.

Applicable standards: Class 1 as per IEC 62053-21 C Class 0.5, 0.5S, 0.2, 0.2S as per IEC 62053-22.

The “s” in 0.2s and 0.5s denotes special accuracy, especially at low current levels. Refer the below table for better understanding.

Accuracy class	Meaning	Max. Error at Rated Current
0.2s	Very high precision - low currents	±0.2% (better at lower currents)
0.2	Very high precision	±0.2%
0.5s	Special high-precision class	±0.5% (better at lower currents)
0.5	High precision	±0.5%
1.0	Standard precision	±1.0%

Accuracy class

Meaning

Max. Error at Rated Current

0.2s

Very high precision - low currents

±0.2% (better at lower currents)

0.2

Very high precision

±0.2%

0.5s

Special high-precision class

±0.5% (better at lower currents)

0.5

High precision

±0.5%

1.0

Standard precision

±1.0%

Accuracy class	Meaning	Max. Error at Rated Current
0.2s	Very high precision - low currents	±0.2% (better at lower currents)
0.2	Very high precision	±0.2%
0.5s	Special high-precision class	±0.5% (better at lower currents)
0.5	High precision	±0.5%
1.0	Standard precision	±1.0%

Accuracy class

Meaning

Max. Error at Rated Current

0.2s

Very high precision - low currents

±0.2% (better at lower currents)

0.2

Very high precision

±0.2%

0.5s

Special high-precision class

±0.5% (better at lower currents)

0.5

High precision

±0.5%

1.0

Standard precision

±1.0%

Key Parameters for CT Selection:

1. CT Accuracy Class

Choose a CT with an accuracy class equal to or better than the DPM’s class.

For 0.2s meters → CT class should be 0.2s or better.
For 0.5s meters → CT class should be 0.5s or better.
For 1.0 meters → CT class can be 1.0 or better.

2. Burden (VA Rating)

Burden is the total impedance (in ohms) of the connected devices (meters, cables) on the CT secondary. Expressed in VA at rated secondary current (usually 1 A or 5 A).
Ensure the CT burden matches the meter’s input burden.
Avoid overloading or underloading the CT, as it affects accuracy.

3. Rated Primary Current

Select based on the maximum expected load current.
Avoid oversizing, which reduces accuracy at low currents.
For variable loads, consider CTs with extended range or multi-ratio CTs.

4. Rated Secondary Current

Common values: 1A or 5A.
1A should be used for long length of the cable between meter C CT. this will reduce the Voltage drop / Power Drop. Lower burden on CT improves precision in measurements.
5A to be used where cable length between Meter C CT is low. Hence Voltage drop is negligible which Result into precision improvement.

Advantage of Site selectable CT / PT in DPM

Lauritz Knudsen Electrical C Automation Digital Panel Meters have feature of Site-selectable CT and PT. This feature offers exceptional flexibility and convenience during installation and commissioning of digital meters. It allows users to configure the meter for different CT and PT ratios directly at the site without replacing hardware or recalibrating the system. This reduces installation time, eliminates the need for multiple meter variants, and minimizes inventory costs. Additionally, it ensures accurate scaling of measured values for diverse applications, from low-voltage panels to high-voltage systems, improving adaptability and reducing errors caused by incorrect ratio settings. Overall, this feature enhances operational efficiency, simplifies maintenance, and supports quick system upgrades.

Conclusion:

Accuracy classes in measuring CTs play a vital role in ensuring precise current measurement for metering and monitoring applications. Classes like 0.2 and 0.5 are suited for high-accuracy needs, while 0.5s is ideal for revenue metering due to its superior performance at low loads. Understanding these classifications helps in selecting the right CT for reliable and efficient power system operation.