MYPV ClearSky, Руководство пользователя

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Resources 18
nameplate while still maintaining proper accuracy. To make this determination, the CTs
rating curves should be consulted to ensure the CT rating is appropriate for your
application.
For relaying however, we may choose a higher ratio CT, possibly a 400:5. This higher
ratio will provide better measurements of fault current conditions that are typically much
larger than the system’s normal operating conditions. A 400:5 CT with a rating factor of
2.0 will provide measurements of up to 800A before saturating.
Regardless of what PT or CT ratio is ultimately selected, the meter and protection relay
devices are configured to understand what instruments are connected via the PTR
(Potential Transformer Ratio, 60: 1 = 60) and CTR (Current Transformer Ratio, 300:5 =
60) settings variables.
The selection of instrument transformers is specific to the application, the
interconnection and facility electrical characteristics, and also an Engineer’s preference.
For the myPV ClearSky™, we have assembled the following table of standard part
numbers for PTs and CTs to use, unless otherwise specified buy the Customer: