TM1700 circuit breaker analysers
Circuit breaker time and travel analysers with DualGround™ testing
Circuit breaker time and travel analysers with DualGround™ testing
Key Benefits
- Perform all relevant measurements in one test
- Fast and safe with DualGround™
- On-screen guidance for ease of use
- Highly versatile operation
Description
With the TM1700 series of circuit breaker analysers, users with regular circuit breaker testing requirements no longer have to choose between low-end instruments designed only for simple applications, and high-end instruments that are versatile but costly. Drawing on our wide experience in circuit breaker testing, Megger developed TM1700 instruments to offer the most useful and widely used features of high-end analysers at a very attractive price. The technology used in the TM1700 is based on Megger’s popular and proven high-end TM1800 series, which remains the most attractive option for those who need the ultimate in circuit breaker testing flexibility. Among the many key features inherited by the TM1700 range is its DualGround™ capability. Dual ground testing enables you to perform tests with both sides of the breaker grounded. This configuration greatly increases operator safety by eliminating the risk of high voltages being induced into the breaker under test. The TM1700 instruments also incorporate active interference suppression, which means they consistently deliver accurate and dependable results, including measurements of PIR times and values, even in electrically noisy environments. Another noteworthy benefit is that all inputs and outputs are galvanically isolated, making it possible to perform all relevant measurements in one test without changing connections. The TM1700 instruments are available in five models, allowing you to choose the specification that best matches your requirements, including if you would prefer a standalone instrument or a computer-controlled one.
Standalone models incorporate a large colour touch screen and offer an intuitive user interface backed by software that simplifies the production of custom test templates. They can also be controlled by a computer as long as it has CABA Win software installed.
The computer-controlled models are supplied with a PC-compatible software package that provides comparable functionality to the standalone models but can only be operated via a PC.
Frequently Asked Questions
Will the TM1700 test my circuit breaker?
The TM1700 series of time and travel analysers are designed to test medium and high voltage AC circuit breakers. These instruments will test one or two breaks per phase circuit breakers and perform up to six motion measurements simultaneously. It is designed to work at all voltage levels, including 765 kV substations. The TM1700 can also test circuit breakers of four and six breaks per phase if the breaker is tested phase-by-phase.
Does Megger have a database of circuit breakers with pass/fail values and correct speed calculation points?
CABA Win includes breaker-specific test plans for multiple CB manufacturers and types, pre-programmed with the correct speed calculation points and pass/fail values. Additionally, the easy-to-use Test Plan Editor (TPE) application can modify existing test plans if your breaker specifications or testing parameters vary.
Can I control the TM1700 with my PC?
All TM1700 units, with an on-board computer or without, can be controlled with your PC as long as it has CABA Win installed.
Do the TM1700 instruments provide power for the circuit breaker?
The TM1700 instruments do not supply power to the circuit breaker. It has a close and open switch that will activate an internal contact to apply external power to the circuit breaker. Station power is typically used, and will be measured by the control module. In the case of commissioning or minimum voltage type tests, Megger has a B10E accessory, a power supply designed specifically for circuit breakers.
How does the TM1700 series differ from your other circuit breaker analysers?
EGIL is a basic analyser for standard time and travel measurements limited to 1 break per phase and 1 common mechanism. EGIL weighs 6,3kg. EGIL200 is a mid range circuit breaker analyser with a modern, simple to use interface for up to 4 break per phase. TM1700 a distribution analyser for up to 2 breaks per phase and control of up to 3 mechanisms. TM1800 is an advanced distribution and transmission analyser with modular system to fully adapt to your needs.
What does SDRM stand for, and how is it used?
SDRM stands for Static and Dynamic Resistance Measurement. Static Resistance Measurement (SRM) is a micro-ohm measurement, a basic ‘DLRO’ or ‘DuctorTM’ test, where a test current is injected through the circuit breaker, and a voltage drop is measured to calculate the resistance value of the contacts. Circuit breaker SRM test results are typically in the low hundreds of micro-ohms to below ten micro-ohms, depending on the breaker type. A Dynamic Resistance Measurement (DRM) is the same measurement performed while the circuit breaker change close to open (contacts are moving). This test is performed on SF6 circuit breakers to measure and evaluate the arcing contacts of the circuit breaker, so you can replace them as they wear out.
Are Dynamic Resistance Measurement (DRM) tests performed on vacuum circuit breakers (VCB)?
DRM tests are only used on SF6 style and oil circuit breakers due to their arcing/main contact design. The test serves as a way to check that a circuit breaker’s arcing contact is significantly long enough to protect the breaker’s main contacts. Since VCBs use a flat contact for arcing and current transmission, the DRM test is not applicable.
Why capture the first trip?
You can test breakers in many ways, but one of the most common tests is timing of the main contacts, which directly indicates the trip time. A typical procedure on a circuit breaker that is in service is: Open the breaker Disconnect the breaker by opening the disconnect switches Ground the breaker Perform timing test Will the timing tests show the true trip time? Not necessarily! Consider a breaker that has been in service without operating for months, or years, before it was taken out of service for testing. It could then suffer from a lack of grease, or dried grease, and corrosion in its bearings. These problems can and probably will slow down the first operation.The problem with the procedure above is that the circuit breaker has been operated at least once before testing begins. This operation might be all it takes to eliminate corrosion problems or sticky bearings and bring the breaker’s trip time up to standard. So when the actual timing test is performed, no problem exists. The service engineer thinks the breaker is in good shape and no further service is needed. Some months later, the corrosion is back, and when a fault occurs, the breaker does not trip fast enough, or maybe not at all. Therefore, capturing the first operation to reveal any problems with the circuit breaker is essential.
What is DualGround™?
DualGround™ is a test method developed by Megger to perform timing while the circuit breaker is grounded on both sides. This allows you to always work between safety grounds, thus negating induced current that flows through the test equipment under normal timing conditions with only one side grounded. Megger uses a patented Dynamic Capacitance Measurement (DCM) that has a simple hookup and accurately measures the contact times of the arcing contact, per IEEE and IEC. With DualGround™ timing, you can test the circuit breaker safer and faster than with traditional timing methods. This method has become a method to test circuit breakers in GIS, Gas insulated switchgears, with difficult configurations, impossible to test under normal conditions and without making any adaption to the installed switchgear connection.
Will the TM1700 instruments test pre-insertion resistors (PIR)?
The TM1700 instruments will test both pre-insertion and post-insertion resistors. They will measure and calculate several parameters for the PIR, including PIR contact time and insertion time. The TM1700 can also measure the value of the PIR as long as it is within the range of 10 Ω and 10 kΩ.
What configuration of the TM1700 should I order?
Multiple configurations of the TM1700 are available, so it depends on the type of testing you want to perform. All configurations will operate the circuit breaker (using station power), time up to two breaks per phase, and record digital motion (up to six channels simultaneously). If linear transducers are needed for testing, then the unit will need the analogue option. You will need extra analogue channels if more advanced testing is required (DRM, First Trip). The smart control module will measure one ‘A’ and one ‘B’ contact through the control circuitry. If you need to measure extra Aux contacts or coil currents for circuit breakers with more than one mechanism (IPO), you will need two control modules and the Aux module (TM1720, TM1750, TM1760). The TM1700 comes in standalone operation with an on-board computer or computer-controlled options.
Can the hardware configuration of the TM1700 instruments be changed?
Once a TM1700 instrument is built, the hardware is fixed. You can add several accessories later as long as the unit has enough inputs to use them (DCM, SDRM, First Trip). If you’re unsure of what is to be tested, or want to leave the option of expanding your testing portfolio till later, then choosing the TM1760 with an extra analogue channel will offer you the most flexibility.
Are travel measurements necessary when timing?
At first, measuring travel on circuit breakers can be intimidating because many connection options exist, and a few settings are required. Therefore, some may choose only to measure timing. By only measuring timing, however, the test may only detect problems after damage has been done to the circuit breaker. You will assess the mechanism’s full stroke and the contacts by measuring travel along with timing. Any overtravel or excessive rebound can be measured and corrected before the circuit breaker contacts reach mechanical failure.
Is there a universal transducer or recommended transducer(s)?
With the multitude of circuit breaker manufacturers and designs in the field, there is no one size fits all transducer. When considering what transducer to use, the best option is to consult the manual or contact the manufacturer to see what transducer they recommend and if any special hardware is needed to connect. If there are a variety of circuit breakers in your fleet, three main kits will cover what is required by most of them. Megger has a 600 mm bulk oil circuit breaker (OCB) kit, a 300 mm SF6 dead tank kit, and a rotary mounting kit. Note: there are still some breakers that may need specific mounts or transducers. Consult the circuit breaker accessories guide for a list of transducers and kits available.
I have older CABA Win files. Are TM1700 files compatible with TM1600 and TM1800 files?
Since the life of a circuit breaker is measured in decades and not years, Megger knows that consistency and compatibility are of the utmost importance when it comes to circuit breaker testing. Old test plans are compatible with the latest version of CABA Win and the TM1700. The software will automatically allocate the channels for proper testing the first time loading the test plan. If new features want to be added or changed, you can use the Test Plan Editor (TPE) for modifications.
Can I make my own test plans?
CABA Win has a built-in wizard called the Test Plan Editor (TPE) that is used to create custom test plans. You can easily select the test types, parameters, and pass/fail values on just a couple of screens. Once you have created a test plan, it can be duplicated to test different breakers and edited in case certain parameters are changed. CABA Win features ca 400 parameters, from universal ones applicable to all breakers to unique parameters for specific breaker models. Therefore, no function will be left untested.
