Megohmmeter Model 6505 - User Manual
17
They are especially useful for monitoring insulation deterioration of revolving
machines or very long cables.
On items of this type, the measurement is initially disturbed by spurious currents
(capacitive charging current, dielectric absorption current) that gradually cancel
out. To measure the leakage current representative of the insulation accurately,
measurements with long durations are necessary.
The quality of the insulation is a function of the results found.
DAR
PI
Condition of the Insulation
< 1.25
< 1
Inadequate, even dangerous.
< 2
> 1.6
< 4
Good.
> 1.6
> 4
Excellent.
3.5.1 Adjustments of the PI
It is possible to modify the PI times to meet specific needs.
Reminder: PI = R 10 min / R 1 min
The first PI time is 1 min. It can be set to values from 30 s to 30 min in 30 s steps.
■
Press and hold the
DISPLAY
button. Turn the rotary switch to the
SET V
var
position. Hold the
DISPLAY
button until
PI_1
appears in the display.
■
You can change the first PI time (PI_1) using the ▲ and ▼ buttons.
■
To save changes, simply turn the switch.
■
The second PI time (PI_2) is 10 min. It can be set to values from PI_1 up to
59 min in 1 min steps.
■
Press and hold the
DISPLAY
button. Then, turn the rotary switch to the
SET
V
lock
position.
■
You can modify the second PI time using the ▲ and ▼ buttons.
■
To save changes, simply turn the switch.
