2-2
CONTROLS AND CONNECTIONS
FRONT PANEL CONTROLS AND METERS (continued)
Guard:
The guard function is selected by a binding post jumper. When the jumper is connected
to
“
Return
”
, leakage current or insulation resistance values associated with the
“
Ground
”
terminal will be measured. When the jumper is connected to
“
Guard
”
, leakage current or
insulation resistance associated with the
“
Ground
”
terminal will not be measured. (See
connection diagram at end of this section.)
Voltmeter Range:
This two position rotary switch scales the DC kilovolt meter. When the switch is rotated to
“
3
”
, the kilovolt meter range is 0-3 kV and the lower black scale is read in order to deter-
mine output voltage. When the switch is rotated to
“
6
”
, the kilovolt meter range is 0-6 kV
and the upper red scale is read in order to determine output voltage.
Current Trip:
This control, located below the currentmeter range select switch, allows the operator to
set the level of leakage current measured by the instrument before high voltage shutdown
occurs. At its highest level (full clockwise) approximately 110% of full scale current will be
allowed. At its lowest level (full counterclockwise) approximately 10% of full scale current
will be allowed before shutdown.
INPUT/OUTPUT CONNECTIONS
Return:
Leakage current or insulation resistance values associated with this terminal is measured
by the
“
DC Microammeter
”
.
Guard:
Leakage current or insulation resistance values associated with this terminal is always
bypassed around the
“
DC Microammeter
”
.
Ground:
Leakage current or insulation resistance values associated with this binding post terminal
may be either measured by the
“
DC Microammeter
”
or bypassed around the
“
DC
Microammeter
”
depending on the position of the binding post jumper.
NOTE: The ground binding post jumper must always be connected to Ground and Guard
(Guard Mode) or Ground and Return (Grounded Return Mode). DO NOT operate without
jumper properly installed.
Also, if the low potential side of the test specimen connected to Return can not or will not
be isolated from ground, the Ground post jumper must be connected to Return. Guard
mode can not be used under these circumstances or the current meter will not function
properly. (See the connection diagram on the following page.)
