Electrical Testing

ELECTRICAL TESTING SERVICE

We provide services for electrical diagnostic tests, we have modern primary and secondary injection equipment that allow us to verify the status of the elements of power and control of a sub-station, generator or industrial complex.

Power transformers

Although transformers are considered to operate under rigorous loading conditions, preventive maintenance is essential to avoid unexpected outputs from the generation system, unavailability of equipment and economic losses due to penalties and repairs.

Our testing service includes:

  • Measurement of the Insulation Resistance (voltage applied up to 500V, 1KV, 2KV, 5KV, 10 kV DC)
  • IP polarization index measurement
  • Measurement of the Dielectric Absorption Ratio DAR
  • Measurement of winding resistance (current applied up to 500 A DC)
  • Measuring the Transformation Ratio (TTR)
  • Phase shift measurement
  • Excitation current and polarity
  • Tests on mechanical protections (relay buscholz)
  • Overpressure
  • Sudden pressure
  • Winding temperature
  • Thermal image
  • Oil level
  • Treatment of dielectric oil
  • Power factor test or Delta Tangent (voltage applied up to 12KV) with frequency sweep Tip-Up (15-400) HZ
  • Dielectric rigidity to oil (maximum applied tension 60KV)
  • Frequency Response Analysis (FRA)
  • Short Circuit Impedance
  • Partial Downloads (PD)

Generators and Motors

The rotating electric machines, motors and generators, for their multiple applications and versatilities, have played a very important role in the development of humanity. In the case of the generator, it supplies the necessary electrical energy for the various daily and specialized activities; On the other hand, the motor provides motive power and is a fundamental part of diverse processes that cover all the fields of the industry.

The measurement of the insulation

The measurement of the insulation using a megohmmeter is a basic test that is part of a maintenance policy and allows to evaluate its insulation. The causes of dielectric breakdown can have different origins:

  • Electric
  • Mechanic
  • Chemical
  • Temperature changes
  • Environmental pollution

To evaluate the condition of the windings of both the rotor and the stator and the state of the core, and to ensure reliability in its operation, the following tests are carried out:

  • Insulation Resistance (IR (t))
  • Polarization index (IP)
  • Dielectric Absorption Ratio (DAR)
  • Steep Voltage (SV)
  • Dielectric Downloads (DD)
  • Leakage current measurement High pot DC
  • Partial downloads (PD)
  • Winding resistance
  • ELCID (electromagnetic core imperfection detection)
  • Electronic verification of WTD wedge attachment (wedge tightness mapping)
  • Detection of short between turns RSO test (Recurrent Surge Oscillograph)
  • Pole Balance
  • Power Factor (Cos) or Dissipation Factor (Tan) 12 KV (15 – 400) HZ
  • Higb Potential – HighPot: o DC or VLF – O.l Hz up to 44 kVrms

Current and voltage transformers

Transformers, whether protection or measurement, are an essential part of the electrical system, its correct operation is verified by means of tests such as:

  • Polarity of the TC and TP
  • Relationship Accuracy and the phase angle
  • Transformation relation
  • Saturation curve
  • Burden measurement
  • Winding resistance
  • Insulation Resistance (IR (t))

Isolated cables

We verify the status of Cables type: XLPE, PE, EPR, PILC etc. Corrosive environments, mechanical stresses, excessive humidity, high operating temperatures or simply the aging of the conductors over time, are determining factors in the deterioration of the insulation, being of the utmost importance to evaluate the behavior of the insulating layers of the conductors to determine their current status and proceed to replace them to avoid a major failure within the industrial facilities. The tests carried out on the cables and bars allow to estimate the useful life, and can be replaced before a possible failure occurs. Our high-voltage equipment is protected against possible short-circuits that may occur during high-pot tests, with an electronic system for active arc regulation that avoids the typical triggering of conventional test equipment when a dielectric failure occurs. Our equipment allows to determine the conditions of the cables without damaging the insulation of the same.

We perform tests of:

  • Insulation Resistance (IR (t))
  • Higb Potential – HighPot: DC / VLF – O.l Hz up to 44 kVrms
  • Partial Downloads (PD)

Voltage regulators (AVR)

The reliability and stability during the operation of a generation system depends on the good state of the voltage regulator. We ensure the operating conditions of the AVR through tests such as:

  • Verification of the generator capacity curve
  • Verification of protections:
    • Overexcitation
    • Minimum excitement
    • Volts / Hertz ratio
    • Overvoltage

Relay protection

The overcurrent, differential and synchronism relays, and those directly associated with the generator, provide protection against faults, based on the measurement of currents and voltages. The correct adjustment and operation of these devices must guarantee the protection of the circuits associated with it to avoid unnecessary stops or risks, for this reason it is vital to verify the status of the relay, the values of the operating curves, the connection logic, operation and its respective signaling.

We verify the operation curves simulating the different types of failures by means of a secondary injection and verify the response of the relay before the scenarios proposed in each adjustment for the different protection functions of the relays:

  • Distance
  • Overexcitation
  • Synchronism and Loss of synchronism
  • Reverse Power
  • Loss of field
  • Instantaneous and timed overcurrent
  • Frequency
  • Differential Current
  • Under 1 Over Voltage
  • Ground fault
  • Over current by neutral
  • Directional overcurrent, etc …

Measuring and protection equipment

We have a modern and complete testing laboratory for the calibration verification of electrical protection and measurement equipment.

Equipment calibration:

  • Voltmeters
  • Ammeter
  • Accountants – Fans
  • Transducers

Dielectric Tests to:

  • Dielectric Gloves
  • Dielectric Boots
  • Helmets
  • Poles
  • Dielectric blankets

Switches and contactors MVCB and LVCB

The switches are designed to meet the predetermined operating conditions and have electrical properties that can be summarized as follows:

  • Property to transport the current.
  • Isolation property.
  • Property to interrupt the flow.

With this in mind, the tests that are applied to the switches seek to evaluate these characteristics, for this reason the contact resistance measurement is made with the circuit breaker in closing to evaluate its capacity to transport current; the measurement of insulation resistance between phases, between poles and with respect to earth is made to verify the level of insulation; finally, the opening and closing times are measured, estimating the times of simultaneity and discrepancy, seeking to evaluate the coordination between the three phases at the moment of operating before a shot or a closing.

The tests are performed on switches, contactors and power disconnectors in low, medium and high voltage.

  • Measurement of Insulation Resistance.
  • Opening and closing times.
  • Times of simultaneity and discrepancy.
  • Penetration and Rebound.
  • Measurement of Contact Resistance

Bushings and Insulators

Analysis of the isolation condition of devices through tests of:

  • Measurement of Insulation Resistance
  • Power Factor (Cos) or Dissipation Factor (Tan)
  • Step Voltage Test
  • Higb Potential – HiibPot:
    • DC
    • VLF · 0.1Hz up to 44 kVrms

Lighting rod

Tests that guarantee the status of voltage dischargers

  • Partial downloads
  • Leakage current
  • Step Voltage Test

Transducers

Verification tests of the operating curve of the voltage transducers. current. phase angle, active power and reactive power.

Study of electrical protections under NEPLAN®

We develop coordination studies of protections under the NEPLAN software, which consist of performing selectivity schemes for possible failures of the electrical system. These studies graphically represent the behavior of the operating current and the protections as a function of time. The study also presents the curves and operating times for other variables, such as:

  • On
  • Voltage
  • Low voltage
  • Frequency oscillations
  • Etc…

Batteries

Online tests to check the status of the batteries of Ploma-Acid and NiCd up to 7000 A-h establishing a final diagnosis of the condition of the cells as good, acceptable or in failure.

Quality studies of electric power

We have state-of-the-art equipment to evaluate the quality of voltage and current waveforms in an electrical potechnology system, thus obtaining a complete analysis of power values, harmonic contents, imbalances, flicker and variations in the form that influence the quality of the service.

With this information and our recommendations, if possible, load balance, reagent compensation, the necessary changes to improve the quality of the electrical power, reducing billing costs and achieving the increase of the useful life of the electrical equipment.

Grounding systems

The main variable in the design of a protective mesh is the resistivity of the soil, we carry out resistivity studies delivering recommendations about the terrain conditions.

The step and contact voltages depend on the good state of the grounding, the measurement of this parameter is essential for the safety of both personnel and equipment in substations.

We carry out the following tests:

  • Measurement of the resistivity of the terrain.
  • Measurement of earthing resistance.
  • Measurement of step voltage and contact.