Figure; Astm D877 Test; Astm D1816 Test - Megger OTS 60AF Guia Del Usuario

Operation

ASTM D877 test

Note:- This specification does not require stirring. Do not fit a magnetic stirrer bar.
1. To commence the test, highlight ASTM D877-87on the main menu and press SELECT.
The display will appear similar to figure 7.
2. On pressing the START key, TEST 1 is initiated and the display appears similar to figure 8.
The display indicates that the 2 minute 20 second initial stand time is being undertaken, and time
remaining is shown. After the initial stand time is complete the high voltage is switched on and
applied. The display appears similar to figure 9.
The high voltage indicator light is illuminated, and the display shows the voltage rising at the rate
of 3 kV/s being applied. This voltage rise continues until breakdown occurs (or up to maximum).
The number of the test in the sequence is displayed together with the words 'IN PROGRESS'.
3. When breakdown occurs (or if the maximum voltage is reached) the test voltage is cut off, the
high voltage indicator light goes out and the display indicates that the 1 minute intermediate
standing period is being undertaken. Time remaining is displayed, alternating with the word
'STANDING'. The previous breakdown voltage is retained on the display, which appears similar
to figure 11.
4. When the intermediate stand time has finished the test voltage begins to rise again as in step
(2), this time for TEST 2, and the cycle of events repeats.
5. For this specification there are 5 consecutive tests. After the test voltage has been cut off on the
last test, the display shows the average breakdown voltage value of the 5 tests in the sequence.
The display appears similar to figure 12.
The three control keys now assume different functions. Press the left hand key labelled VIEW to
sequentially display the breakdown voltage values of each individual test, followed by their
standard deviation value.
If the automatic print option is pre-selected, the results will be printed automatically at the
conclusion of a test sequence. If not, press the centre key, labelled PRINT to obtain a print-out of
the results. When the printer is in operation the display shows 'PRINTING PLEASE WAIT'.
Press the NEW key to return to the start of the ASTMD877 test followed by the left hand START
key to repeat a test sequence or the MENU key to return to the main menu.
Note:- At any time during a test sequence, pressing the right hand control key, labelled STOP will end a
test and return to the test option display. Similarly during printing the left hand key labelled STOP
can be used to stop the print function and return to the average breakdown display.

ASTM D1816 test

Note:- This test requires continuous stirring by a paddle type stirrer, using the special vessel available
for this specification. See figure 13. The test can be performed with standard oil test vessels but
this will not conform to the specification. The magnetic stirrer may be selected if required. The
paddle stirrer is connected to the socket in the rear of the test chamber at the time the test
vessel is placed on the high voltage horns.
1. To commence the test, highlight ASTM D1816-84a on the main menu and press SELECT. The
display will appear similar to figure 7. Repeated pressing of the centre key labelled STIRMODE
changes the stirring choice through MAGNETIC, IMPELLER or NONE. Press the right hand key
labelled MENU to return to the main menu.
2. On pressing the START key, TEST 1 is initiated and the display appears similar to figure 8.
If selected, the stirrer operates and continues to do so throughout the test sequence.
The display indicates the stirring mode selected and that the 3 minute initial stand time is being
undertaken. Initial stand time remaining is shown in minutes and seconds.
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