IMP57
EN - 8
5. OPERATING INSTRUCTIONS
5.1.
PHASE TO PHASE IMPEDANCE MEASUREMENT AND PHASE TO PHASE-
THREE-PHASE PROSPECTIVE SHORT CIRCUIT CURRENT CALCULATION
WARNING
Never use the instrument in electrical plants with Nominal phase to phase
voltage higher than 415V or a Nominal phase to neutral voltage or phase to
ground voltage higher than 240V.
The Phase to Phase impedance measurement entails the flowing of a current
up to 200A between the above said conductors. This can cause tripping of
magnetothermal switch having rated value lower than 200A. If necessary
execute the measurement upstream the switch.
If possible disconnect all the low impedance loads connected downstream the
point where the test is to be carried out as the impedance of the above said
loads results to be in parallel with the impedance under test.
Always make sure that the upper and lower metal plate of the alligator clips
make good contact with the conductors of the circuit under test.
Never disconnect the Alligator clips or Test leads during the Test.
P1 C1 C2 P2
1
2
3
N
PE
Fig. 3: Instrument connection for phase to phase impedance measurement
1. Connect the IMP57 RS232 to MASTER instrument through RS232 cable (see
paragraph 4.2).
2. Connect the alligator clip to the Electrical plant according to Fig. 3.
3. Insert the 4 safety connectors into corresponding instrument's inputs
according to
sequence P1, P2, C2, C1
(see Fig. 3).
4. Check if the STATUS LED is light in Green.
5. Switch ON the MASTER instrument, select the "Phase to Phase Measurement mode"
and Start the Test (see chapter 6).
For further details and description about Test results and Save procedure see chapter 6.
