TCT-12C
TCT-12C Transformer Capacity, Load and No-Load Tester
30 to 31,500 kVA · ±(0.2% + 3 digits) · five automatic corrections
Establishes what a transformer actually is by measuring it, then runs the no-load and load tests that say whether it is still sound. A missing or disputed nameplate is not an obstacle, it is the reason to reach for this.
TCT-12C · measuring terminals, keypad and panel printer
What one connection measures
Connect once and the instrument works through the characteristic tests together, rather than each being a separate set-up with a separate chance of a wiring error.
Capacity
Determined by measurement against the standard ratings, not read off a plate. The reason the instrument exists.
No-load loss and current
Iron loss and excitation current with the secondary open, the first indication of core condition.
Load loss
Copper loss under short circuit, the figure that moves as windings age or deform.
Short-circuit voltage
And the impedance voltage and percentage short-circuit impedance derived from it.
Harmonics
Content and distortion on the supply feeding the test, so a poor network is not mistaken for a poor transformer.
Vector check
Three-phase voltages and currents drawn as a diagram, so the wiring is confirmed before the numbers are believed.
Capacity is established by measurement, which is what makes the instrument useful on a transformer whose nameplate is missing, painted over or disputed.
Five corrections, applied before you see the number
The adjustments that otherwise get done by hand, or not at all
A loss measurement taken on a real supply, at whatever voltage and current the site can provide, is not the figure the standard asks for. These five corrections are what turn one into the other, and the instrument applies every one of them to every result.
Harmonic content is measured alongside, so a distorted supply is visible rather than silently folded into the loss figure.
Know the limit before you travel
Load testing draws real current, so there is a ceiling on what one instrument can do unaided. Worth checking against the transformer you are going to before the van is loaded.
A single instrument performs the load test outright on units up to this size. Nothing else is needed on site.
Above 1600 kVA the test is run at a third of rated current and the instrument converts the result to the rated figure.
Beyond that, an external CT or PT extends the measuring range, so larger units are still within reach with the right accessory. No-load testing is not subject to the same limit.
Technical specifications
| Measures | Capacity · no-load current and no-load loss · short-circuit voltage and load loss · impedance voltage and percentage short-circuit impedance · harmonic content of voltage and current |
|---|---|
| Capacity range | 30 to 31,500 kVA · single-phase and three-phase transformers |
| Voltage | Line 0 to 750 V, phase 0 to 450 V · ranges switch automatically · ±(0.2% + 3 digits) |
| Current | 0 to 100 A · ranges switch automatically · ±(0.2% + 3 digits) · an external CT extends the range |
| Frequency | 40 to 65 Hz, accuracy class 0.2 |
| Method | Three-meter measurement · capacity determined by measurement, not from the nameplate |
| Corrections | Applied automatically to every result: waveform, temperature, non-rated voltage, non-rated current and calibration |
| Wiring check | The instrument verifies its own connection before measuring and displays a vector diagram of the three phase voltages and currents |
| Load test capability | Up to 1600 kVA at rated current · up to 2500 kVA at one third rated current, converted |
| Insulation | Above 100 MΩ · leakage current below 3.5 mA · the power connection on the chassis withstands 1500 V |
| Display | 320 × 240 LCD with brightness control · English interface · menu prompts throughout |
| Printer | Panel printer fitted, results on paper at the transformer |
| Memory | 500 groups, held through a power failure, with specimen settings and measurement time recorded against each · electronic clock · transferable to a computer |
| Power | AC 220 V ±10% |
| Safety | IEC 61010-1 · CE marked |
| Part number | 988012 |
What’s in the case
- TCT-12C main unit
- Test clamps, yellow, green and red
- Voltage and current test leads
- Communication lead for the PC link
- Power lead
- Carry case, manual and calibration certificate
The test clamps are colour coded to the three phases, so the wiring check has as delivered. Results print at the transformer, and 500 groups are held for the report.