Test sets selection guideline
Dielectric tests have crucial importance in the process of developing, manufacturing and operation of high voltage electrical equipment. It is impossible to replace tests with calculations and expert evidences. As a result, it is proper tests that define the quality of designed and output products.
Don’t let anybody call in question the quality of your products. Use for dielectric tests only test sets, which meet standards, have relevant documents, allow you to register your electrical laboratory at Goverment agencies and provide fulfillment of safety regulations during its operation. Requirements to high voltage test sets for electrical equipment insulation strength tests contained in a variety of particular standards and other regulatory documents. Unitary standard is not available.
Our guidelines for choosing the high voltage test set for electrical equipment insulation tests (acceptance tests, on-site tests) are shown below
How to choose the h.v. test set for electrical equipment dielectric tests
(resolving questions sequence)
1. Set purpose?
The set is destined for electrical equipment insulation strength tests at compliance with GOST 1516.3 requirements and meet GOST 1516.2 requirements.
2. Set test voltage range?
The voltage range is accepted, in which:
• Sustained short-circuit current of set exceed 0.3 A (GOST 1516.2);
• Measurement accuracy of test voltage conventional effective value (peak value divided by , GOST 1516.2) not worse ± 3% (GOST 17512);
• Test voltage values reproducibility not worse 1.0% (GOST 1516.2).
3. Set load carrying capacitance?
Represented in form of single or multiple loading curve: Load rating (in units of test object capacitance (nF), or in units of wattage (kVA)) correspondence from test voltage (can also be represented in form of single values table).
4. Set of documents?
• Operational documentation (operation manual, logbook);
• Calibration certificates for all measuring instruments, being part of set, and set primary qualification certificate;
• Sertificate of safety;
• Pattern approval certificate of measuring instruments;
5. Some set output characteristics at the test voltage?
• Sinusoidal voltage curve shape, both half cycles have similar shape;
• Test voltage peak value ratio to effective value should be in the range of ±0.07;
• High voltage measurement system should include voltage divider or transformer, in-line on the side of HV (GOST 1516.2).
6. Tests with direct voltage?
• Pulse coefficent no more than 3% (GOST 1516.2);
• Voltage drop at test object from leakage currents and PD at test voltage – no more than 10% (GOST 1516.2).
Additional factors, subject to pay attention at:
• Transportation and storage conditions;
• Possibility of applying the set for on-site testing;
• Completeness and particularity of accompanying and operational documentation;
• Maintenance feature, serviceability, SPTE.
In List of standards section presented main native and international documents, containing requirements to h.v. dielectric tests of electrical equipment and to test equipment for carrying out these tests.