Audible Signal; Precautions When Making Dc Insulation Tests - AEMC 1000N User Manual

$XGLEOH6LJQDO
When the PUSH-TO-TEST button is in the ON or LOCK-IN position, an
audible signal will result. This signal consists of approximately one beep
every six seconds (ten beeps per minute). The signal can be used as a
time base for monitoring the duration of the test. On the MΩ and GΩ
ranges, the signal indicates that the instrument is in operation and that
the selected DC test voltage may be present on the terminals of the
instrument.
3UH.DXWLRQVZKHQ0DNLQJ'&,QVXODWLRQ7HVWV
• The equipment should be taken off the line sufficiently in advance to
permit it to cool to ambient temperature.
• When you are testing windings, they should be clean and dry; let
solvents and cleaners evaporate. Should foreign matter or wet
surfaces be present, erroneous readings may result. (A clean, dry
sample's resistance may rise for 5 to 15 minutes, whereas a wet, dirty
one will stabilize quickly).
• Make sure that the equipment tested is properly discharged and
grounded before testing.
• When testing individual windings, connect all other windings (not
under test) together and ground to motor frame.
• When testing phases, be sure they are open to test each individually.
• After applying a test voltage, allow sufficient discharge time. As a rule,
discharge twice as long as tested.
Note: The instrument voltmeter will indicate the discharge voltage at the
terminals.
Megohmmeter Model 1000N/1100N
- 15 -