Table of Contents
- 1 What is insulation resistance what should be value of IR for 100kVA and 1000kva transformer?
- 2 What should be the insulated resistance for a transformer?
- 3 What is the rating of the transformer for the voltage of about 11KV?
- 4 What is the minimum insulation resistance value?
- 5 How do you calculate transformer rating?
- 6 What kVA rating is required for a transformer?
- 7 What is winding resistance test in transformer?
- 8 What is the acceptable Ir value for a transformer?
- 9 What is the minimum insulation resistance required for HV installation?
- 10 What is the insulation resistance (IR) for electric motor?
What is insulation resistance what should be value of IR for 100kVA and 1000kva transformer?
(2) IR Value for Transformer:
| Voltage | Test Voltage (DC) LV side | Min IR Value |
|---|---|---|
| 6.6KV to 11KV | 500V | 400MΩ |
| 11KV to 33KV | 1000V | 500MΩ |
| 33KV to 66KV | 1000V | 600MΩ |
| 66KV to 132KV | 1000V | 600MΩ |
What should be the insulated resistance for a transformer?
IR Values For Electrical Apparatus & Systems At a pressure of 1000 V applied between each live conductor and earth for a period of one minute the insulation resistance of HV installations shall be at least 1 Mega ohm or as specified by the Bureau of Indian Standards.
How do you test insulation resistance on a transformer?
How to Perform an Insulation Resistance Test on A Transformer
- Isolate the equipment.
- Test the tester. Short the tester leads. Set the voltage range (usually 500V)
- Identify the test points. Test between windings. Test between windings and earth.
- Perform the test and record the result.
What is the rating of the transformer for the voltage of about 11KV?
11000 V
Here is the rating of Transformer is 100kVA. But Primary Voltages or High Voltages (H.V) is 11000 V = 11kV.
What is the minimum insulation resistance value?
Insulation resistance should be approximately one megohm for each 1,000 volts of operating voltage, with a minimum value of one megohm. For example, a motor rated at 2,400 volts should have a minimum insulation resistance of 2.4 megohms.
What is the insulation resistance test?
An insulation resistance (IR) test measures the total resistance between any two points separated by electrical insulation. Such tests are useful for checking the quality of insulation, not only when a product is first manufactured but also over time as the product is used.
How do you calculate transformer rating?
Calculate the current from the voltage/amperage (VA) specification or the power rating designated in watts. Both figures mean basically the same thing. Divide either the VA or wattage rating of the transformer by the voltage. This will give you the current rating.
What kVA rating is required for a transformer?
The kVA rating will be = 2 kV × 8 A = 16 KVA.
What is the insulation resistance?
The insulation resistance is the resistance in ohms of wires, cables and electrical equipment. It is important to guard against electric shocks and avoid equipment damage from accidental discharges. The method of measuring the insulation resistance is to test and assess the state of the isolation (head and body.)
What is winding resistance test in transformer?
A winding resistance test of a transformer is carried out as a type test, routine test and also as a field test. In the factory, it helps in determining the following: Calculation of winding temperature at the end of temperature rise test of transformer. As a benchmark for assessing possible damages in the field.
What is the acceptable Ir value for a transformer?
Acceptable Limits: Unless otherwise recommended by the manufacturer, the IR Values of 500MΩ may be considered as the minimum satisfactory values at 30°C (one minute measurements) at the time of commissioning as a thumb rule for all transformers above 66KV voltage rating.
How to test the insulation resistance of a transformer?
Connect the test leads (avoid joints). Apply the test voltage and note the reading. The IR. Value at 60 seconds after application of the test voltage is referred to as the Insulation Resistance of the transformer at the test temperature. The transformer Neutral bushing is to be disconnected from earth during the test.
What is the minimum insulation resistance required for HV installation?
As per IE Rules-1956: At a pressure of 1000 V applied between each live conductor and earth for a period of one minute the insulation resistance of HV installations shall be at least 1 Mega ohm or as specified by the Bureau of Indian Standards.
What is the insulation resistance (IR) for electric motor?
Insulation resistance (IR) value for electric motor Example-1: For 11KV, Three Phase Motor. IR Value =11+1=12 MΩ but as per IEEE43 It should be 100 MΩ Example-2: For 415V,Three Phase Motor