Testing & Inspection

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A Culture of Safety

Bami Technologies provides a variety of electrical acceptance testing, commissioning, and maintenance testing for a wide range of clients, including Utility, Generation, Renewables, Industrial, Transit, Data Centers, and Commercial Facilities throughout North America. We are committed to providing a culture of safety and technical expertise to set the Standard of Excellence in the Power Industry. We offer a complete turnkey solution for your electrical testing needs and the expertise you require, whether it involves active monitoring as part of a larger test program or stand-alone analysis of a device or system.  

A.) Insulation Testing

The insulation resistance(IR) measurement is a standard routine test performed on all types of electrical wires and cables. As a production test, this test is often used as a customer acceptance test, with minimum insulation resistance per unit length usually specified by the customer. Results obtained from IR Test are not intended to find localized defects in the insulation as in an actual HIPOT test but rather give information on the bulk material’s quality.

Selection of IR Testers (Megger):

  • Insulation testers with a test voltage of 500, 1000, 2500, and 5000 V are available.
  • The recommended ratings of the insulation testers are given below:
Voltage LevelIR Tester
650V500V DC
3.3KV2.5KV DC
66Kv and Above5KV DC

B.) Dielectric Withstand Testing (AC/DC)

Dielectric withstand testing is used to evaluate the insulation strength of electrical devices and apparatus. When testing, it is important that the insulation be tested at a much greater voltage than normal to ensure that it is not marginal. If voltages are set correctly, dielectric withstand testing using a dc voltage provides the same outcome as using an ac dielectric test. In addition, dc testing offers significant safety and performance improvements over ac testing.

It is performed in AC or DC with voltages varying from some hundred volts to several tens of kilovolts. The choice of the nature and value of the test voltage is determined by standards that apply to the product being tested.
In the absence of standards, the following rule of thumb is used: the test is always performed with a voltage of the same nature as that under which the sample operates.

 Example: A Direct Current for batteries and Alternating Current for transformers.
The formula gives the maximum value: Voltage test = 2 x operating voltage +1000 V.
The dielectric strength test can be made to be destructive or non-destructive.

Equipment / Cable RatingDC Test Voltage
24V To 50V50V To 100V
50V To 100V100V To 250V
100V To 240V250V To 500V
440V To 550V500V To 1000V
2400V1000V To 2500V
4100V1000V To 5000V