Operation Manual

BENNING CM 5-1 02/ 2011
16
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Please observe the restrictions in the lower measuring range!
DC voltage measurements are not possible within the range of
- 0.7 V
DC
... 2.1 V
DC
.
AC voltage measurements are only possible starting from
voltages of > 1.3 V
AC
.
See figure 2: Direct/ alternating voltage measurement with AUTOTEST
function
8.3 Current measurement

Do not apply any voltage to the contacts of the BENNING CM 5-1!
Any possibly connected safety measuring leads have to be
removed.
- Switch the BENNING CM 5-1 on by means of the key (grey) J.
- Operate opening lever 3, clamp single wire live conductor centrally by
means of the BENNING CM 5-1 current clamp.
- On the digital display , the AUTOTEST function is shown by the
„AutoSense“ symbol 4. It automatically determines the required measuring
function (current) and the ideal measuring range.
- Read the measured value on the digital display  on the BENNING CM 5-1.
See figure 3: Direct/ alternating current measurement with AUTOTEST func-
tion
8.4 Resistance measuring and acoustic continuity testing
- Switch the BENNING CM 5-1 on by means of the key (grey) J.
- The black safety measuring lead has to be contacted with the COM jack K
on the BENNING CM 5-1.
- The red safety measuring lead has to be connected to the jack for V, Ω and
L on the BENNING CM 5-1.
- Bring the safety measuring leads into contact with the measuring points.
- On the digital display , the AUTOTEST function is shown by the
„AutoSense“ symbol 4. It automatically determines the required measuring
function (resistance/ continuity) and the ideal measuring range.
- Read the measured value on the digital display  on the BENNING CM 5-1.
- If the conductor resistance between the COM jack K and the jack for
V, Ω and L 25 Ω up to 400 Ω, the fitted buzzer sounds on the
BENNING CM 5-1.
See figure 4: Resistance measurement
See figure 5: Continuity testing with buzzer
8.5 Diode testing
- Switch the BENNING CM 5-1 on by means of the key (grey) J.
- The black safety measuring lead has to be contacted with the COM jack K
on the BENNING CM 5-1.
- The red safety measuring lead has to be connected to the jack for V, Ω and
L on the BENNING CM 5-1.
- Bring the safety measuring leads into contact with the measuring points.
- On the digital display , the AUTOTEST function is shown by the
„AutoSense“ symbol 4. It automatically determines the required measuring
function (diode) and the ideal measuring range.
- Read the measured value on the digital display  on the BENNING CM 5-1.
- For a standard Si diode applied in conduction direction, a conduction volt-
age between 0.4 V and 0.8 V is displayed. If no forward voltage is detected,
first check the polarity of the diode. If still no forward voltage is displayed,
the forward voltage of the diode is beyond the measuring limits.
See figure 6: Diode testing
9. Maintenance

Before opening the BENNING CM 5-1, make sure that it is free
of voltage! Electrical danger!
Work on the opened BENNING CM 5-1 under voltage may be carried out
only by skilled electricians with special precautions for the prevention of
accidents.
Make sure that the BENNING CM 5-1 is free of voltage as described below
before opening the instrument:
- First remove the two safety measuring leads from the object to be meas-
ured.
- Then disconnect the two safety measuring leads from the BENNING CM 5-1.
- Switch off the BENNING CM 5-1. For switching it off, press and hold the key