Table of Contents
Advertisement
Quick Links
Advertisement
Table of Contents
Subscribe to Our Youtube Channel
Related Manuals for METREL A 1283
Summary of Contents for METREL A 1283
- Page 1 Leakage current clamp A 1283 User manual Version 1.4, Code no. 20 751 508...
- Page 2 Mark on your equipment certifies that this equipment meets the requirements of the all applicable EU (European Union) regulations No part of this publication may be reproduced or utilized in any form or by any means without permission in writing from METREL.
-
Page 3: Table Of Contents
A 1283 Leakage current clamp Warnings ....................4 Description of leakage current clamp ..........5 Meaning of symbols ............... 5 Maintenance ..................6 Inspection ..................6 Cleaning ..................6 Service and calibration ..............6 Leakage current clamp operation ............7 Measuring of leakage currents ............ -
Page 4: Warnings
Do not use the current clamp if any damage is noticed! Do not leave open signal output terminals of the current clamp with current output (A 1283) during measurement to avoid damage and electric shock on secondary side. Never enclose conductor in the jaw unless the clamp is connected to measuring instrument! This safety precautions are not necessary for the GUARD output. -
Page 5: Description Of Leakage Current Clamp
Leakage current clamp 2 Description of leakage current clamp The A 1283 is a 1000/1 ratio leakage current clamp for measuring alternating currents in the range from 0.5 mA to 10 A. The A1283 current clamp is specially designed to be used in combination with METREL BetaPAT Plus, OmegaPAT Plus, DeltaGT, and MultiservicerXA testers. -
Page 6: Maintenance
It is essential that your clamp is regularly calibrated in order to guarantee the technical specification listed in this User manual. We recommend 2- year calibration interval. Metrel encloses an original calibration certificate with every new instrument and current clamp. -
Page 7: Leakage Current Clamp Operation
A 1283 Leakage current clamp 4 Leakage current clamp operation 4.1 Measuring of leakage currents 4.1.1 Origins of leakage currents Leakage currents are currents driven by active conductors of a distribution system or electrical equipment to earth and/or protective conductors. -
Page 8: Leakage Currents In Normal Operation
A 1283 Leakage current clamp 4.1.2 Leakage currents in normal operation Typical leakage currents in normal operation are: Leakage currents caused by input filters in electrical equipment connected between live and earth (filters, monitors). The capacitors in input filters have a capacitance of ca. 10 nF to 100 nF (see Fig. -
Page 9: Leakage Currents In Fault Conditions
A 1283 Leakage current clamp 4.1.3 Leakage currents in fault conditions Faults in electrical installations and equipment can cause additional continuous or short-lasting leakage currents. Typical faults that can cause increased leakage currents are: Deterioration of insulation (because of pollution, moisture, corrosion). -
Page 10: Problems Caused By Leakage Currents
A solution is to add RCD(s) and divide the circuits in a way that the leakage currents in normal operation stay below 20 % of the nominal value of each RCD. For further information refer to METREL handbook Guide for testing and verification of low voltage installations. - Page 11 A 1283 Leakage current clamp On Fig. 3 two non-sinusoidal leakage currents are shown. Fig. 3: Examples of atypical leakage current Impaired safety due to fault, earth, touch voltages Leakage currents that are flowing into earth and PE conductors cause a voltage drop on exposed conductive parts.
-
Page 12: Measuring Leakage Currents With Current Clamps
A 1283 Leakage current clamp 4.2 Measuring leakage currents with current clamps The simplest way of measuring leakage current is the measurement with leakage current clamps. The measuring principle is shown on Figure 4 and in Equations 4, 5. Fig. 4: Measuring principle of current clamp – direct and differential method Eq. -
Page 13: Differential Method
A 1283 Leakage current clamp 4.2.2 Differential method The sum of currents through two or more active (embraced) conductors is measured in the differential method. If no current is leaking into PE conductors / earth the sum of currents through active conductors must be exactly zero regardless of the load currents. -
Page 14: Testing Procedures
A 1283 Leakage current clamp 4.3 Testing procedures 4.3.1 Finding sources of excessive leakage current The described testing procedure in this chapter is applicable for troubleshooting in the installation and electrical equipment in case of nuisance tripping of protective devices. - Page 15 A 1283 Leakage current clamp By using any of the procedures described above the faulty point can be determined very precisely. Fig. 7: Finding source of excessive leakage current – by disconnection Fig. 8: Finding source of excessive leakage current – measuring...
-
Page 16: Insulation Resistance Testing
A 1283 Leakage current clamp 4.3.2 Insulation resistance testing The standard high voltage insulation resistance test can sometimes not be carried out – if the installation is not allowed to be disconnect for a longer time or sensitive equipment is connected. -
Page 17: Influencing Quantities
A 1283 Leakage current clamp 4.4 Influencing quantities Unfortunately measurements with leakage current clamp are subjected to different influencing quantities that have a big impact on their performance. High uncertainty and non-repeatability of readings often lead to wrong interpretations. Three most important influencing quantities are described in this document. -
Page 18: Influence Of External Electric Field
A 1283 Leakage current clamp 4.4.3 Influence of external electric field The electric field caused by voltage on measured conductors or any other conductors/ parts in vicinity can interact with the current clamp through capacitive coupling. This can happen through the sensor, housing, test cables, measuring instrument etc. -
Page 19: Consideration Of Influencing Quantities
A 1283 Leakage current clamp Fig. 11: Minimizing influencing quantities, correct placement of conductors Fig. 12: Minimizing influencing quantities, avoiding external magnetic and electric fields 4.4.6 Consideration of influencing quantities Only high quality current clamp can accurately measure in range of mA in presence of external fields and high load currents. -
Page 20: Other Important Current Clamp Parameters
A 1283 Leakage current clamp 4.5 Other important current clamp parameters 4.5.1 High measuring range Leakage clamps with a high measuring range can be used for other applications too. A 20 A measuring range will cover most of application in standard residential electrical installations. -
Page 21: Leakage Current Sensor Or Meter
(multi meter, power meter or installation tester). The external measuring instrument often offers more functions than a current clamp meter. Combination of METREL current sensors with METREL test instruments offers a lot of additional measuring functions (logging, harmonic analysis, etc.) and storing of results. A current sensor is also cheaper than a current meter if the user already possess an appropriate instrument. - Page 22 A 1283 Leakage current clamp Short overview of leakage current clamp applications Electrical Applications Suited Notes Installations current clamp Leakage Troubleshooting: MD 9270 Very useful 1.0 mA – 150 current - nuisance tripping applications, simple to measurements of protective measure.
-
Page 23: Technical Specifications
A 1283 Leakage current clamp 5 Technical specifications List of instruments that support operation with A 1283 Current clamp is designed to be used in combination with following METREL testers: PAT tester BetaPAT Plus MI 3304, PAT tester Omega/ BetaPAT Plus MI 3305,... - Page 24 A 1283 Leakage current clamp...
Need help?
Do you have a question about the A 1283 and is the answer not in the manual?
Questions and answers