Self Check Tests: Checks For Major Safety And Functional Parts; Fuse Replacement - Megger OTS 60PB Guide De L'utilisateur

Operation
SELF CHECK Tests: checks the major safety and functional parts
The 'SELF CHECK' option enables the following parts of the circuit to be checked:–
EEPROM
Key Pad
Display Contrast
Door Test
Stir Test
Test Voltage
Watchdog
Note:– It is not necessary to have the oil test vessel filled with sample oil for the 'SELF CHECK' tests.
1. From the main menu select the 'SELF CHECK' option. The first display screen to appear gives a
warning that an EEPROM test will clear the user memory. The arrow keys take the labels 'YES', 'NO'
and 'QUIT'. (Pressing the latter key returns to the main menu.)
Caution:– If the 'YES' button is pressed the EEPROM memory will be cleared and this will
include the parameters set up by the user as well as any results data. If this
information is wanted then the 'YES' button must not be pressed.
2. Pressing the 'NO' key avoids the EEPROM test and moves straight to the Key pad test. Each key,
when pressed, causes its number to appear on the display thereby showing that it is active.
3. Press the left hand key and then the right hand key to move to the Display Contrast test. A test
pattern appears on the display and then the left hand and centre keys can be used to darken or
lighten the display contrast. Press select to set the Contrast level.
4. The Door Test comes next. Open the door half way down and note that the HV Safety Interlock door
test has PASSED (failure to work properly would lock out the Self Test sequence at the Door Test
stage). Leave the door open and press Next.
5. The Stir Test comes next. Press Start and look up inside the test chamber to see that the stirrer is
rotating. The high voltage safety interlock is operational during these tests with the door open. Press
Stop and observe the stirrer stops rotating. Close the door.
6. The Test Voltage check comes next. Press Start and the displayed voltage will ramp up to
breakdown or the maximum of 60 kV if good oil is in the vessel. Alternatively the electrodes and their
spindles may be removed or pushed back to the maximum air gap possible when a breakdown value
between 30 – 40 kV is expected. The kV lamp should be illuminated up to breakdown. Press Next.
7. The Watchdog timer test comes next. This monitors the system continually and resets the equipment
in the event of a failure. Check for the information Watchdog Pass which occurs for about 3 seconds.
Note:– A flashing battery symbol will appear on the display when the internal rechargeable battery is
almost exhausted. The battery must be re-charged. If this is not done and testing continues a
battery symbol with a cross through it appears.

Fuse Replacement

Two fuses are fitted in holders mounted on the pocket at the rear of the instrument. Ensure that the test
set is disconnected from the charger or vehicle lead set before fuses are replaced. To replace a fuse
unscrew and remove the cap in the centre of the holder. Remove the fuse, replace with a new one and
refit the cap.
It is important that fuses of the correct rating and type are fitted (see the Specification for the details).
FS1 is the external input fuse rated at 6,3 A HBC, type F, to IEC 127/1. FS2 is the internal battery fuse
rated 6,3 A HBC, type F, to IEC 127/1.
19