METREL MI 3280

Digital Transformer (DT) Analyser (MI 3280) is a Multi-function, portable battery (Li-ion) powered test instrument with excellent IP protection: IP65 (case closed), IP54 (case open), intended for diagnosing of: turn ratio, phase deviation and excitation current of single and three phase transformer and winding resistance of single and three phase transformer.A 4.3” (10.9 cm) colour LCD display with touch screen offers easy-to-read results and all associated parameters. The operation is straightforward and clear to enable the user to operate the instrument without the need for special training (except reading and understanding this Instruction Manual). Test results can be stored on the instrument. PC software that is supplied as a part of standard set, enables transfer of measured results to PC where can be analysed or printed.

For turn ratio of three-phase transformer rA,rB,rC measurement should be selected. Measurement parameterization must start with selection of the IEC Vector Group (see Appendix D – Vector groups for details), which is fundamental parameter. Make sure it is set correctly or the results will be wrong. The Vector Group selection is divided into two sections. First select H-X Configuration, which will ease the further selection by limiting the amount of choices for specific Vector Group.

Available functions and features offered by the Digital Transformer Analyser:

Turn ratio measurement of single and three phase transformer; Phase deviation between high voltage and low voltage winding Excitation current when measuring turn ratio Winding resistance measurement of single and three phase transformer; Auto Sequences®; Visual Tests; Memory Organiser.

Test mode: single

Open-terminal test voltage: 1 V, 5 V, 10 V, 40 V or 80 Vac

Test voltage frequency: 55 Hz, 65 Hz or 70 Hz

Short-circuit test current: > 250 mA @ 55 Hz, 80Vac,> 1 A @ 55 Hz, 10 Vac

Test voltage shape: sine wave

r definition: turn ratio

Limit range (r): 0,8 … 8000

Δr definition: turn ratio deviation (calculated value)

Limit range (Δr): -100,0 % … 100,0 %

i definition: excitation current

Limit range(i): 0,1 mA … 1,1 A

Definition: phase deviation (between H and X voltage)

Limit range (): -180,00° … 180,00°

Measuring time: 8,5 s (per phase)

Automatic range selection: yes

Automatic excitation voltage selection: .no