CT and PT Testing

Current Transformers (CT) along with Potential Transformers (PT) are Instrument Transformers. About 20% of customers account for 80% of utilities’ revenues. Those 20% are by definition high load and have CTs and maybe PTs. Due to the high error tolerances, the revenue loss is significant if the instrument transformers are not tested properly.

Top CT/PT revenue loss issues include:  

• Ratio Mismatch between Actual and Billing System  
• CT/PT Shorted  
• CT Polarity Reversal  
• CT/PT Over-burdened  
• Wiring Issues  
• Lightning Strike  
• Open Secondary  
• CT Age  
• Tampering by Customer