The electrical laboratory of LLC «Liman-trade» is designed for the following types of work in electrical installations up to and above 1000 V:

1. Testingof electrical equipment (voltageup to 10 kV) with higher voltage, including:

• DC machines;
• AC motors;
• Power transformers, autotransformers, oil reactors and grounding arc suppression reactors (arc suppression coils);
• Measuring current transformers;
• Measuring voltage transformers;
• Oil circuit breakers;
• Vacuum circuit breakers;
• Gas-insulated switches;
• Load break switches;
• Disconnectors, separators and shortings;
• Completewireways (busbars);
• Assembling and connecting busbars;
• Capacitors;
• Fuses, disconnectorfusesfor voltages above 1000 V;
• Bushings and bushing insulators for substations;
• Electrical equipment up to 1000 V (including the circuit breakers at rated current of 400 A or more).

2. Testing of cable lines (up to 10 kV voltage) with higher voltage, including:

• Cables with paper insulation;
• Cables with plastic insulation;
• Cables with rubber insulation.

3. Measurement of insulation resistance of electric wiring and cable lines with voltage up to 10 kV.

• Secondary circuits and electrical wiring;
• Power cable lines (voltage up to 10 kV).

4. Measurement of DC resistance of electrical equipment (up to 10 kV voltage), including:

• Synchronous generators and compensators;
• DC machines;
• AC motors;
• Measuring current transformers;
• Measuring voltage transformers;
• Oil circuit breakers;
• Vacuum circuit breakers;
• Load break switches;
• Disconnectors, separators and shortings;
• Fuses, disconnectorfusesfor voltages above 1000 V;
• Power transformers, autotransformers, oil reactors and grounding arc suppression reactors (arc suppression coils).

5. Measurement of grounding devices resistance.

6. Checking the circuit between grounded installations and their elements.

7. Operability check of circuit breakers.

8. Operability check of residual current devices(RCD).

9. Check L-N loop in electrical installations up to 1000 V with the TN system. 

10. Visual inspection

Equipment of the LLC «Liman-trade» electrical laboratory

1. MegaohmmeterE6-32 — measures the insulation resistance with voltage up to 2500 V and metal-on-metal connection.

2. Dielectrics testing deviceAID-70Ts — allows testing with high voltage and burning.

3. MilliohmmeterMIKO-7 — meters the DC resistance.

4. Grounding resistance meter IS-20 (the device is intended for measuring resistance of grounding elements, metal-on-metal connections, continuity of protective buses, measuring the soil resistivityby the automated calculation.

5. Load measurement kit with the current regulator RТ-2048-12 — intendedfor measuringthe effective triggering current of maximum circuit breakers (up to 12 kA).

6. Voltamperemeter and phase meter RS-30 withKTIR-500 clamps.

7. Multifunctional device for measuring parameters of electrical installations METREL MI 3102H Eurotest SE 2.5 kV.

• measurement of insulation resistance up to 20 GOhmwith voltage up to 2500 V;
• measurement of absorption and polarization coefficients, R60;
• verification of continuity of protective buses;
• measurement of line impedance and calculation of short-circuit current;
• checkingof parameters of standard and selective RCDs ofA, AC, F types with rated breaking currents from 10 mA to 1 A;
• measurement of grounding resistance by 3-wire scheme;
• measurement of current up to 20 A;
• measurement of voltage and frequency;
• phase sequence check.

8. Digital multimeter APPA 103N

Optional: standard current signal generator RZU-420;
Digital cable length meter — Reis-50.

The entire fleet of equipment is verified and certified. The laboratory is fully equipped with all means of protection for work in electrical installations.

The staff have been qualified to conduct tests and have theaccess levelcomplying the requirements of Rostekhnadzor.

Why is it necessary to test the electrical equipment?

A complex of tests and measurements in electrical installations is a mandatory requirement of the Federal Service for Environmental, Technological and Nuclear Supervision, Fire safetyand Ministry of Emergency Situations at performing acceptance tests. A technical report based on the tests results is a part of a set of documents required for the commissioning of installed electrical system. Worksare performed in accordance with the regulations MPOT, PTEEP, PUE, and their list depends on the type and composition of the equipment.

Technical report

The technical report includes:

1. Visual inspectionprotocol;
2. operability check of circuit breakers up to 1000 V;
3. measurement of insulation resistance of distribution devices, wires and cables of three-phase power supply networks up to 1000 V;
4. L-N loop check by measuring single-phase short circuit current;
5. grounding and protective buses continuity testing;
6. measurement of dissipation resistance of grounding devices;
7. conclusion;
8. list of defects.