Megger AVO 830, Руководство пользователя

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www.megger.com AVO®830 and AVO®835 20
Measurements
To Detect Phase Rotation / Sequence
1. Set-up the instrument as shown in Fig 2.
•
Set the Function Dial to
•
Red test lead: V terminal
•
Black test lead: COM terminal
The range locks to 1000 V and ----- shows on the Primary display.
2. Connect the V and COM probes to L1 and L2 phases of the three phase supply (1).
If the voltage and frequency are correct the instrument shows LOC on the Primary display.
3. Once LOC shows change L1 to third phase (L3) within eight seconds (2).
4. If phase changeover is not detected within eight seconds t-OUt (Time Out) shows on the Primary display.
5. If phase changeover is detected within eight seconds, the phase sequence result will show as:
•
L1 L2 L3 (phase sequence is OK / Forward), or
•
L3 L2 L1 (phase sequence is NOT OK / Reverse)
6. After three seconds test will start again on its own.
Resistance Measurement
To measure resistance a small current is sent through the circuit to be tested. Because this current flows through
all possible paths between the test probes, the resistance reading represents the total resistance of all paths
between the test probes. Therefore to measure the resistance of:
„
A Resistor: Disconnect at least one connection (1)
„
A Variable resistor: Disconnect at least two connections (2)
Hz
CAT III 1000V
CAT IV 600V
COM
FUSED
100mA
V
10A
Ω
AVO835
RANGE
MODE
MIN MAX
AVG
REL %
REL
Low Z
HOLD/Auto
ac+dc
APO
Lo
Hz
Hz
°F
Hz
V
Hi
A
mA
OFF
OFF
Ω
°C
M
Ω
1 2
3
1
3 2
2.
1.
Fig 3: Resistance Measurement Set-up
Caution: To avoid possible damage to the instrument or to the equipment under test, make sure that
the circuit power is disconnected and all high-voltage capacitors are discharged before resistance is
measured.