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.
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.
Useful links:
Spec Sheet: Download PDF
Manuel: Download PDF
Connection Guideline: Download PDF
Introduction Video: Watch Tutorial
ST-3/XT3 Overview: Watch Overview
Related Articles
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 phases ...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 ...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 ...What is the length of the current loop cables from the junction box that they branch out from?
The original length of the accessories it’s 15 feet. But if you require an additional 50' and 100' length, extension cables can be purchased. 50' (ST-3/EXT50): https://probewell.com/our-products/accessories-st/st-3-ext50/ 100' ...Can I use in on a 5S installations?
Yes. In order to use the ST-3/XT3 on a 5S, 35S or 45S installation, you must use the 5S, 35S and 45S adapter which is included when you purchase a ST-3/XT3. Useful links: Product ...