Megger TPT420 LCD/LED Two-Pole Voltage Tester

Product Information

Works below the tipping thresholds of RCDs, RCBOs and safety breakers when testing circuits between phase and earth

In a surge test, a short-duration test current with a fast rise time – typically around 100 ns – is generated and applied to the motor coil. The test equipment captures the coil’s response, which takes the form of a decaying oscillation – or ‘ringing transient’. If the motor coil were in air, the pulse would be travelling at almost the speed of light and the voltage would be evenly distributed across the coils. But in a motor, the coil is not in air, it is wrapped around a steel core, and so the pulse travels much more slowly. The MET1000 All-in-one true RMS electrical tester is a multifunctional voltage andcurrent tester that gives electricians and electrical engineers a versatile and robust handheldmeterwith detachable test leads. Featuring both LED and LCD displays, it gives youa 200 A AC and1000 V AC/DC tester designed for everyday use. CATIV 600 V/CATIII 1000 V rated, with an IP65 housing for added protection, it reduces the number of testers required in the professional’s tool bag. On-Line testing – that is, testing while the motor is running – can also be carried out on an as-needed basis with a portable on-line monitor like the Baker EXP4000. Finally, this ergonomic tester is equipped with a bright LED torch, GS38 probe tip shrouds, and an IP64-rated housing. The Megger TPT420 is also supplied with a carry pouch. CCVTs are devices capable of dual function. One function they can perform is to provide highly accurate voltage conversion for measuring devices, protection relays, and automatic control systems, while the other is to couple high-frequency power-line carrier (PLC) signals onto the transmission system for communication and control purposes.

Megger VF5 Voltage Tester Technical Specifications 

Continuity function: detects continuity between 0 and 500kΩ and alerts the user by issuing an audible and visual alert Power frequency (50 / 60 Hz) power factor / tan delta testing has been the standard for evaluating the condition of solid and liquid insulation in transformers for over 100 years.With the introduction of 1 Hz power factor / tan delta testing, Megger is revolutionizing insulation diagnostics. When testing at 1 Hz, the dielectric losses due to moisture, contamination and increase liquid conductivity are better observed. Power factor or tan delta test at 1 Hz provides superior detection sensitivity to early and advanced insulation deterioration. Combined with power frequency measurement, 1 Hz delivers immediate insulation assessment without the need for trending or proprietary databases. And it’s the same with a surge test generated by a Baker DX tester. It applies a voltage and rise-time to enable you to see the inter-coil response, but with a signal controlled in voltage, time and energy, so that the impact on the motor is similar to the spikes that the motor receives as a result of typical power-system variations during everyday operation. Inside the voltage tester, this current passes through a known resistance. The voltage drop across this internal resistance is then measured and displayed on the tester's meter or screen. This provides the user with a reading of the voltage present. In some cases, for basic testers, this voltage may simply trigger a light or a sound to indicate the presence of voltage rather than providing a precise numerical value.

In some circumstances, the CVD capacitive reactance can resonate with the magnetizing reactance of the inductive voltage transformer and the compensating reactor cores. This unwanted effect is called ferro-resonance and can give rise to large and damaging voltages across the inductive and capacitive elements. To avoid this, a ferroresonance damping circuit is installed in parallel with one of the secondary windings. A bad turn will short and this will be shown by a jump in the ringing frequency of the coil (it becomes in effect a ‘different’ coil at this point in the test). Large frequency jumps can be clearly seen on the tester display, but the instrument’s software also uses mathematical analysis to reveal anomalies that are less easy to spot by eye. The instrument has abright, integrated LED torch to helpyou when working in poorly lit environments and, it is safetyrated at CAT IV 1000 V with an IP64 housing, and conforms to the latest IEC/EN 61243-3 and DIN VDE 0682-401 standards. For compliance, GS38 probe tip shrouds are provided as standard, along with a protective storage and carry pouch. Ratio validation to confirm that the performance of the CCVT matches its nameplate values for ratio and phase accuracy requires the use of specialised test equipment. For this reason, it is not commonly carried out in the field. If validation testing is performed, however, the results should fall within the appropriate accuracy parallelograms given in standards, such as IEEE C57. 13- 2016. One such example is provided in Figure 2, wherein a CCVT is used for metering purposes.

Megger TPT420 LCD/LED Two-Pole Voltage Tester Technical Specifications 

The Megger TPT420 LCD/LED Two-Pole Voltage Tester is an easy-to-use and ergonomic voltage meter optimised for safety and reliability. It is designed for testing electrical installations making it ideal for electricians and electrical engineers. However, it can also be used to test automotive, fire alarm, and solar/ PV systems. Megger TPT420 LCD/LED Two-Pole Voltage Tester Key Features There are other effects due to filtering of the higher frequency components of the pulse-wave as a result of attenuation by the steel and the coils own inductance. The speed of propagation of the pulse wave is, however, the key aspect that allows the surge test to detect bad turns. A basic ratio test can be carried out by exciting the primary side of the CCVT with a 10 kV source and measuring the secondary voltage with a digital multimeter. However, this supplies no measurement of phase deviation, which is required to validate the accuracy of the CCVT. When the probes of a voltage tester are connected to two points in an electrical circuit (commonly one end to a suspected live conductor and the other to a ground source), a closed circuit or loop is formed. This allows electrical current to flow from the higher potential to the lower potential.