Quick question about Connecticut Light & Power's TOU-GS-3 schedule. The tariff mentions CT ratio requirements for demand measurement but doesn't specify the minimum ratio or accuracy class. Customer has 800A service with 400:5 CTs. Are these adequate for accurate demand billing or do they need higher ratio transformers? The metering section is pretty vague. - Clifford H.
Connecticut Light & Power Rate Schedule TOU-GS-3 CT Ratio Requirements
Clifford, 400:5 CTs should be fine for 800A service. Most utilities require CTs to be sized so normal operating current falls between 10-100% of the CT rating for good accuracy. With 800A service, your 400:5 CTs are properly sized. The accuracy class requirements are usually in the utility's service standards document, not the rate tariff itself. - Claudia B.