Struggling with how to explain CT ratio errors to clients who don't have electrical backgrounds. Found a 400:5 CT reading as 200:5 at a PSE&G account - $8,400 annual overcharge. But when I try to explain current transformers and multipliers, their eyes glaze over. Any good analogies or simplified explanations that work?
Explaining CT Ratios to Non-Technical Clients
Kurt, I use a 'speedometer' analogy. The CT is like the speedometer in your car - it measures how much electricity is flowing. If the speedometer is calibrated wrong (200:5 instead of 400:5), you're getting charged for twice as much 'speed' as you're actually using. Simple but it clicks for most people.
I like the water meter comparison. Tell them the utility installed a water meter that reads every gallon as two gallons. Same concept - the meter (CT) is supposed to scale down the measurement but it's scaling wrong. Usually gets an immediate 'oh, that's not right' reaction.
Kirk makes a good point about the photos. I always include nameplate shots in my reports now. Also helps to show them a correct installation at another meter for comparison. 'This one matches, that one doesn't' is pretty hard to argue with.
All great suggestions. The key is making them feel smart enough to catch the error themselves rather than overwhelmed by technical details. I usually end with 'this is exactly why you hired us to check these things' - reinforces the value of the audit process.
What I've found helpful is showing them the actual CT nameplate photo versus what's programmed in the meter. Visual proof that there's a mismatch. Then I just say 'this number should match this number, and it doesn't.' No technical explanation needed.
For visual learners, I draw two circles - big circle is actual usage, small circle is what gets measured. Then show how the wrong ratio makes the small circle bigger than it should be. Keep the math out of it entirely and just focus on 'you're being charged for more than you use.'