Accidentally hitting a power cable during project excavations can lead to costly repairs and create seriously hazardous situations. Digging in the wrong place can also cause significant and unnecessary delays – and run-on costs for the project.
Lourenco Menezes, Comtest Sales Account Manager, explains the importance of having the correct equipment for the job. The Amprobe rugged and durable UAT600 series is specifically designed to pinpoint underground utilities accurately and buried services up to 30 m deep, offering accuracy to a depth of six metres for this job.
The AMPROBE UAT-600 is used to locate underground cables and pipes accurately and efficiently.
Mines generally use so-called ‘thumper’ technology for cable fault location – a portable high voltage (+25 kV) surge generator is used to ‘thump’ the cable. At the fault point, a high-current arc makes a thumping sound. The disadvantages of thumping are that it is time-consuming, and the cable, exposed to high voltage surges, may be degraded and will definitely require re-insulation. In addition, this methodology cannot find short circuit faults.
In December 2020, a Free State gold mine experienced a damaged cable incident and the breach needed to be pinpointed urgently. An external thumper contractor was called in and the eventual diagnosis was that the cable was damaged at a length of 120 m. An excavation team was called in and dug to that length. Unfortunately, no breach in the cable was found. A new channel was then dug at 60 m and still no fault was found. On the third tracing attempt the team located the breach across the road and on a different cable.
The consequences of the cable breach/fault included numerous days of lost production and the cost of the thumper analysis. For the cost of an AMPROBE UAT600 cable locator, the mine would not only have reduced the risks associated with the test, it would also have an instrument that can provide an accurate reading, location diagnosis and a solution within a day.
In the AMPROBE UAT-600 series, the locating kit is supplied complete and ready for use with a transmitter, receiver, test lead kit, batteries and additional fuses, all in a mobile, protective duffle bag. The UAT-620 kit also includes a signal clamp for transmitting a signal when it is not possible to make electrical contact with the cable to be traced. For applications where ground fault locating is required, the UAT-600 Transmitter can be used in combination with the optional A- Frame accessory.
Main applications
The UAT-600 series is used to:
- Locate energised 50/60 Hz cables carrying current
- Identify the location of all metallic utilities: pipes*, energised and de-energised cables
- Trace individual pipes* or cables (energised or de-energised)
[*Tracing of non-metallic pipes and conduits is possible after inserting metal fish tape or cable.]
Three testing modes
- Passive power mode (50/60 Hz) – tracing energised lines conducting current (no transmitter is necessary)
- Passive radio mode (RF) – using surrounding radio waves to trace underground utilities (no transmitter is necessary)
- Active mode – using the UAT-600-T Transmitter.
Three active modes using the UAT-600-T Transmitter
- Induction – the transmitter will automatically start to radiate a signal around it using an internal antenna, used for tracing individual cables where there is no access to the line to connect test leads or a clamp
- Direct connection with test leads – the most reliable method to trace individual cable or pipe
- Clamp (included in the UAT-620 kit, optional for the UAT-610 kit) – provides an efficient and safe method of applying a locate signal to a cable, where it is not possible, or not safe to access a cable to make an electrical contact.
Special applications
- Two frequency options: 8 kHz and 33 kHz
- Locate non-metallic pipes and sewer lines
- Take depth and current measurements
- Measure voltage, resistance and output current
- Advanced locating with two people
- Locate ground faults with the optional AF-600 A-Frame accessory.
Unparalleled safety
A key distinguishing feature of the UAT-600 Series is its CAT IV 600 V safety rating. This allows users to connect the transmitter directly to an energised line up to 600 V in a CAT IV environment, safely. Previously, if a crew needed to trace a specific electrical line by transmitting a signal through it, the line had to be de-energised first, adding time and reducing productivity.
For more information visit: www.comtest.co.za
