Current Measurement - Conrad F 113 Bedienungsanleitung

5.2 Current Measurement

Measure DC or AC currents as follows (please study the diagrams
below). An arrow marked on the „clamp head" is a symbol for
the direction of current flow.
a) Switch on the clamp-on ammeter.
b) Open the clamp-on ammeter using the clamp-opening lever.
When measuring DC current, never grip more than one insu-
lated conductor. When measuring AC current, grip only one
insulated conductor in a one-phase system or several insulated
conductors in a multi-phase system.
Important!
Just under the clamp opening there is a contact insulation con-
sisting of a thick-layer of plastic. When measuring/gripping a
conductor or conductor rail, never grip beyond the contact insu-
lation - POTENTIALLY LETHAL HAZARD !!!
c) Close the clamp around the current-carrying conductor by
releasing the clamp-opening lever. The contact surfaces of
the clamp must be safely closed, and the conductor(s) must
be able to move in the clamp opening. When reading off
values, check that the conductor is centrally located, i.e. bet-
ween the lines marked.
d) If you are measuring a DC current, the slide switch „DC/AC"
must be set to „DC". With DC current measurement, the
direction of current flow is significant. If a minus sign „−" is
displayed in front of the read-off value, it probably means
that the direction of current flow has been overlooked
(arrow marking on clamp head). Ahead of DC current mea-
surement, the display must be set to zero. Adjust the setting
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knob „DCA ZERO ADJ" (by turning left or right) until the dis-
play shows either „000" (in the 1000 A range) or „00.0 V" (in
the 400 A range).
Important!
During this adjustment, no conductor should be located in the
clamp and the clamp should not be in the vicinity of a field of
magnetic disturbance (e.g. loudspeakers, electric machines, etc.).
The contact surfaces of the clamp arms must be clean and closed.
e) If setting to zero cannot be carried out as required, i.e. a rest
value remains displayed, proceed as follows:
- After several DC current measurements, there may be
residual magnetism in the clamp. This can be removed by
changing the direction of the current you are measuring
by reversing the position of the clamp-on ammeter („+"
marking to „−" and „−" marking to „+").
- Open and close the clamp several times. Then attempt
setting to zero once more.
Important!
Never measure currents in measuring circuits in which voltages
greater than 600 VDC or VACrms can occur, since otherwise a
potentially lethal hazard obtains. Never attempt to measure cur-
rents greater than 1000 Arms.
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