Electronic Energy Meter Accuracy Check

What is Accuchek LT+

Accuchek LT+ is a portable electrical and electronic device that is used for checking accuracy error of 1-phase 2-wire electronic energy meters and 3-phase 4-wire electronic energy meters (LT only) such as Genus, Larsen & Toubro (LnT), Landis & Gyer (LNG), HPL, TTL, Secure Meter Limited (SML) and Linkwell meter installed in various field. It supports both static and electro-mechanical meter types.

Accucheck LT+

Why Need to Test Electronic Energy Meter

The electronic energy meter is a device used to measure the amount of electrical energy consumed by the consumer. The power company charge the amount according to consumed energy which is recorded on a meter. Electricity meters are the main source of revenue for energy suppliers. Testing of the energy meter is necessary because, without accurate metering data, the supplier will lose revenue. Suppliers are responsible for ensuring that metering is installed and maintained correctly so that consumers are billed correctly. If the energy meter is running fast then the consumer will pay an extra amount rather than the actual bill amount to your respective energy supplier and if the meter is running slow then you are saving some bill amount, this amount depends on your meter’s slow percentage suppose a meter accuracy error is found -20% means you will be charged only for 80% of your bill amount. This error will not detect in normal view, a special device Accuchek LT+ is used to check this error percentage.

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Accuchek LT+ Specifications

Voltage240 V ± 30%
Basic current1 A or 5 A (direct mode)
Clamp-on CT100 A/150 A/200 A/300 A/500 A
Frequency                         50 Hz ± 5%
Accuracy                             Class 0.2S
Accuracy                             Class 0.2S in direct mode
AccuracyClass 0.5S with clamp-on CT
Maximum current          120% Ib
Power factor     0 lagging to UPF to 0 leading
Temperature range       -10 °C to +50 °C
Weight9.5 kg (approx.)
Dimensions (W x H x D)350 mm x 465 mm x 172 mm (approx.)
Connections      Fully insulated cables for voltage and current
Communications             RS-232 serial port for data transfer to analysis software (included)
Optical scanner frequency rangeUp to 200 Hz, un-modulated.

Architecture and Process

Accuchek LT+

How to Check 3-Phase Meter using Accuchek LT+

Electronic energy meter is sometimes installed incorrectly, with wires swapped over or with incorrectly configured instrument transformers. The inherent complexity of three-phase installations makes such errors difficult to detect and rectify. 

  • Turn on the Accuchek device and set it in 3-phase mode.
  • Taker power supply from electronic energy meter output terminal or cut-out switch for Accuchek LT+ with RYB phase sequence.
  • Connect the RYB lead wire with their respective RYB jack. Connecting the wrong phase sequence will cause the phase sequence error. So always connect the correct phase sequence.
  • Connect the clamp on CT on the input supply wire of the meter with the RYB phase sequence.
  • Feed the meter details in the Accuchek LT+ device for eg. sticker number, meter manufacturer name, meter serial number, manufacturing year, basic current, accuracy class and phase mode.
  • After feeding these details check the clamp on CT is connected forward. If CT is reversed then they cause an error.
  • After setup, all connections start the scanner which will count the pulse according to the running load.
  • The scanning process takes a few minutes. After finishing the scan, the error percentage will appear. (The standard error per cent is ±2.99 % and it will be negligible for good meters)
  • If the test value exceeds ±2.99 then the meter will be fast or slow according to ± sign.

Precautions Before Testing

  • Use all electrical safety precautions while testing eg. wear safety show etc.
  • Do not operate the device at high voltage, check the voltage before starting the test.
  • Read all testing guidelines before starting the test.

You can avail of this electronic energy meter check process by contacting your nearest electricity board.

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