IET Labs, Inc. 1864-1644, User And Service Manual

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INTRODUCTION
1864-1644 Positive Polarity Megohmmeter
1
Chapter 1
INTRODUCTION
1.2 Opening and Tilting the Cabinet
To open the cabinet, refer to the pictorial graphic on
the rear panel of the unit; see Figure 1-2. The Flip-Tilt
cabinet can be opened by placing the instrument on
its rubber feet with the handle away from you. Push
down on the handle and the instrument, located in the
upper part of the case, will rotate to a vertical position.
While holding the handle down with one hand, rotate
the instrument to the desired position with the other
hand and then slowly release the handle.
1.3 Controls, Connectors and Indicators
Figure 1-1 shows the front-panel controls, connectors
and indicators of the 1864. Table 1-1 lists and identi-
fi es them. Figure 1-2 shows the rear panel controls and
connectors, and Table 1-2 lists and identi fi es them.
1.1 Description
The 1864-1644 (Figure 1-1) indicates resistance
from 50 k
Ω to 200 T Ω . These ranges are suitable for
leakage-resistance measurements of most types of
insulation used in electrical instruments, electronic
devices and components, etc (Section 4). The 1864
has a voltage range from 10 to 1090 V that can be set
in 1 Vdc steps from 10 to 109 V, and in 10 V steps
from 100 to 1090 V by using the TEST VOLTAGE
switches on the front panel.
The 100-volt setting is the EIA standard for measure-
ment of composition,
fi lm, and wire-wound resistors
above 100 kilohms. The 500-volt setting is a standard
value in the measurement of the insulation resistance
of rotating machinery, transformers, cables, capaci-
tors, appliances, and other electrical equipment.
A regulated power supply and charging circuit per-
mit rapid and accurate measurement of the leakage
resistance of capacitors.
Guard and ground terminals permit measurement
of grounded or ungrounded two-or three-terminal
resistors.
A panel warning light indicates when voltage is ap-
plied to the test terminals and alerts users to the safe
operation of the instrument.
WARNING
High voltage is applied to the measurement terminals of
1864-1644 Megohmmeters at all times, except when the
function switch is set to DISCHARGE. While the current
is limited to a value that is not dangerous under most
conditions, the energy stored in a capacitor connected
to the terminals may be LETHAL. Always set the function
switch to DISCHARGE before you connect or disconnect
the unknown.