12/ 2005
BENNING CM 4
13
The red safety measuring cable has to be connected to the jack for V, Ω, Hz
on the BENNING CM 4.
- Bring the safety measuring lines into contact with the measuring points,
read off measured value on the digital display
on the BENNING CM 4.
- If the conductor resistance between the COM jack
and the jack for V, Ω
25 Ω, the fitted buzzer sounds on the BENNING CM 4.
See figure 5:
Resistance measurements
8.5 Frequency measurement via current measuring pliers
Do not apply any voltage to the output contacts of the
BENNING CM 4! Any possibly connected safety measuring
cables have to be removed.
- Use the rotary switch
to select the required function (Hz) on the
BENNING CM 4.
- Operate opening lever
, clamp single wire live conductor centrally by
means of the BENNING CM 4 current probe.
- Read off the digital display unit
.
See figure 6:
Frequency measurement via current measuring pliers
9. Maintenance
Before opening the BENNING CM 4, make quite sure that it is
voltage free! Electrical danger!
Work on the opened BENNING CM 4 under voltage may be carried out only by
skilled electricians with special precautions for the prevention of accidents.
Make the BENNING CM 4 voltage free as follows before opening the
instrument:
- First remove the two safety measuring lines from the object to be
measured.
- Then disconnect the two safety measuring cables from the
BENNING CM 4.
- Turn the rotary switch
to the switch setting “OFF”.
9.1 Securing the instrument
Under certain circumstances safe operation of the BENNING CM 4 is no longer
ensured, for example in the case of:
- Visible damage of the casing.
- Incorrect measurement results.
- Recognisable consequences of prolonged storage under improper
conditions.
- Recognisable consequences of extraordinary transportation stress.
In such cases the BENNING CM 4 must be switched off immediately,
disconnected from the measuring points and secured to prevent further
utilisation.
9.2 Cleaning
Clean the casing externally with a clean dry cloth (exception: special cleaning
wipers). Avoid using solvents and/ or scouring agents for cleaning the
instrument. It is important to make sure that the battery compartment and
battery contacts are not contaminated by leaking electrolyte.
If electrolyte contamination or white deposits are present in the region of the
batteries or battery casing, clean them too with a dry cloth.
9.3 Battery change
Before opening the BENNING CM 4, make quite sure that it is
voltage free! Electrical danger!
The BENNING CM 4 is fed by two 1.5-V mignon batteries.
A battery change (see Figure 7) is required, if
the battery symbol
appears.
Proceed as follows to replace the batteries:
- Disconnect the safety measuring cables from the measuring circuit.
- Disconnect the safety measuring cables from the BENNING CM 4.
- Set the rotary switch
to the switch setting “OFF”.
