Live LV CT Tester: Model 595LV
The model 595LV is designed to test the translational integrity of Low Voltage* metering CTs which are permanently commissioned and cannot be taken offline. The 595 LV also allows the user to actively measure a metering CT’s admittance and secondary burden. When combined with the measured current error, the 595 LV satisfies the majority of the minimum testing requirements of a Live metering CT installation.
The model 595LV is designed to test the translational integrity of
Low Voltage* metering CTs which are permanently commissioned
and cannot be taken offline.
To determine the translational accuracy of a live CT, the 595LV
measures the primary and secondary current over a predetermined
number of samples.
The current ratio and phase angle errors are calculated for each sample
and an average is taken to give the final translational current and phase
error accurate to within 0.1% of the CT manufacturer’s specification at
rated current.
To measure the primary current the instrument has provision for two types of current clamps:
– a 50mm ID 1000:1 ratio clamp, able to measure primary loads up to 1200 Amps
– an 85mm ID 3000:2 ratio clamp, able to measure primary loads up to 3600 Amps
The secondary current is measured by the 595LV using one of two methods:
– 8 to 20mm ID 1000:1 ratio clamp, able to measure up to 10 Amps
– Direct connect to CT terminals, able to measure up to 10 Amps
The clamps listed above are electronically compensated for accuracy within the 595LV, so the correct
clamp must be selected from the unit’s menu before a test is performed.
Other features:
– Live admittance testing
– Colour touch screen
– GPS, for accurate sampling and phase synchronization
– USB for record transfer to flash stick
– Bluetooth for communication with High Voltage clamp accessory, 595HV
– Mains and battery powered
– Battery capacity is 12 Vdc / 30Wh lithium
* – LV or Low Voltage metering installations are typical less than 600 VAC.