Maintenance; Securing The Unit; Battery Replacement; Fuse Replacement - Benning MM 12 Bedienungsanleitung

See figure 10:
8.8 Temperature measurement
- Use the rotating switch J to select the required function (
- Press the Function key 5 (down/ ▼) of the BENNING MM 12 to switch over to °C or °F.
- Connect the temperature sensor (type K) to the COM jack L and to the jack K observing
correct polarity.
- Place the contact point (end of the sensor lead) on the point to be measured. Read the
measurement value on the digital display 1 of the BENNING MM 12.
See figure 11:

9. Maintenance

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Before opening the BENNING MM 12, ensure that it is not connected to a
source of voltage! Electrical danger!
Any work required on the BENNING MM 12 when it is under voltage must be done only by a
qualified electrician. Special steps must be taken to prevent accidents.
Before opening the BENNING MM 12, remove it from all sources of voltage as follows
- First remove the both safety measuring leads from the measurement points.
- Remove both safety measuring leads from the BENNING MM 12.
- Turn the rotating switch J to "OFF".

9.1 Securing the unit

Under certain circumstances, the safety of the BENNING MM 12 can no longer be guaranteed.
This may be the case if:
- there are visible signs of damage on the unit,
- errors occur in measurements,
- the unit has been stored for a long period of time under the wrong conditions, and
- if the unit has been subjected to rough handling during transport.
In these cases, the BENNING MM 12 must be switched off immediately, removed from the
measuring points and secured to prevent it from being used again.
9.2 Cleaning
Clean the outside of the unit with a clean dry cloth. (Exception: any type of special cleaning cloth).
Never use solvents or abrasives to clean the testing unit. Ensure that the battery compartment
and the battery contacts have not been contaminated by electrolyte leakage.
If any electrolyte or white deposits are seen near to the battery or in the battery compartment,
remove them with a dry cloth, too.

9.3 Battery replacement

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Before opening the BENNING MM 12, ensure that it is not connected to a
source of voltage! Electrical danger!
The BENNING MM 12 is powered by four 1.5 V mignon batteries (IEC LR6/ type AA). Battery
replacement (see figure 12) is required as soon as all segments of the battery symbol 4 have
disappeared and the battery symbol is flashing.
Proceed as follows to replace the batteries:
- First remove the safety measuring leads from the measurement circuit.
- Remove the safety measuring leads from the BENNING MM 12.
- Turn the rotating switch J to "OFF".
- Remove the protective rubber holster O from the BENNING MM 12.
- Put the BENNING MM 12 face down and unscrew the lower screw of the battery compart-
ment cover.
- Lift the battery compartment cover off the bottom part.
- Remove the discharged batteries from the battery compartment.
- Insert the new batteries into the battery compartment at the provided places (please
observe correct polarity of the batteries).
- Lock the battery compartment cover into place on the bottom part and tighten the screw.
- Place the BENNING MM 12 into the rubber protection frame O .
See figure 12:
Remember the environment! Do not dispose of used batteries with domestic
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waste. Dispose of them at a battery-collection point or as toxic waste. Your
local authority will give you the information you need.

9.4 Fuse replacement

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Before opening the BENNING MM 12, ensure that it is not connected to a
source of voltage! Electrical danger!
The BENNING MM 12 is protected against overload by means of an integrated fuse (G melt
insert) 440 mA fast-acting and an integrated fuse (G melt insert) 11 A fast-acting (see figure 14).
Proceed as follows to replace the fuses:
12/ 2018
Frequency measurement
Temperature measurement
Battery replacement
BENNING MM 12
) on the BENNING MM 12.
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