How does the ST-3/XT3 works?
ST-3/XT3 : Transformer Rated Wireless Site Tester
This unit is a socket type tester, that obtains the reading directly from the secondary of the current and potential transformers.
- It does not require any external load to perform
tests and it is powered up by the installation.
- The back of the unit is easily configurable to
accommodate the different meter installations using removable twist-tabs that does not require any tool to install.
- A form selector switch can be toggled to select
the proper form of the installation. The unit is lightweight for ease of
configuration and operation.
- The accessories are plugged in the front of the unit with a 12-pin port connectors. The unit can perform tests on all three phases
simultaneously. The accessories have an electronically compensated interface linked to 3 Rogowski cables (figure 1) for CT testing or 3 banana plug (figure 2) end cables and alligator clamps for PT testing.
- The accessories can be plugged in the front of the unit prior to installing the tester in the meter socket.
- Once the tester installed, the only manipulation left is to hook the Rogowski cables around the CTs and the clamps to be clamped to the PTs.
Figure 1 Figure 2
The tester can be controlled from a safe distance using a mobile device such as smart phone, tablet, or laptop computer.
For overhead installations, another accessory is available that acts as an interface between the HV Probes (Sensorlink) and the tester.
Cables extensions (50 feet and 100 feet) are also available for use with the CT and PT accessories when CT and PT are further than 15 feet away from the meter socket.
Can I use it whitout accessories? How many accessories can I use with?
Yes, it can work without any accessories, depending on the test you wish to perform on the site. The only test that it is not available without accessories would be the primary/secondary analysis (Ratio Test). The accessories available are 3 ...
What is the procedure when installing the tester?
The ST-3/XT3 is compatible with CT rated installations forms 3S, 4S, 6S, 8S and 9S, it is also compatible with installation forms 5S, 35S and 45S using the included adapter. Before testing a CT rated installation in the field, always make sure that ...
How about yearly calibration of the tester? Do the accessories need to be calibrated?
The units are calibrated at the factory before delivery to your facilities. We suggest verifying accuracy of the testers using the build in accuracy test in the application at least once a year or as per local PUC or company regulations to ensure ...
For calibration is it required to send back the tester back to the factory or can we run a calibration using our shop standard?
The tester provides a built-in test mode that aims at validating the accuracy of the device by comparing it to a high-accuracy, NIST-traceable polyphase test board or standard. This test is meant to be done in a lab environment and at a rate of one ...
When the memory is full does it start overwriting the old tests automatically or does it notify the user when the memory is full before starting to overwrite?
When there is no more space in the memory of the system, the device will display a system error when trying to save the data. The device does NOT automatically overwrite test data. At this point, the user must transfer test reports to a computer and ...