3-15
IM CW240E
Preparation for Safe Measurements
3
3.4
Connecting Clamp-on Probes
WARNING
• For safety, connect a clamp-on probe to the CW240 main unit and then to the
circuit under test.
• Before clamping a clamp-on current probe onto the circuit under test, turn off
power to the circuit under test. It is very dangerous to clamp or unclamp the
clamp-on probe without turning off the circuit under test.
• Be sure to connect a clamp-on probe to the secondary side of the circuit un-
der test such as current limiters (circuit breakers). Should an accident such
as a short occur, other circuits will be protected by these circuit breakers.
• Be extremely careful not to connect a voltage circuit to the current input ter-
minals or a clamp-on probe to the voltage input terminals. An improper con-
nection may result in not only damage to the circuit or equipment under test
or the CW240, but also an injury to personnel.
• Do not connect any clamp-on probe not required (not used) for measurement.
• For measurements, do not use any current probes other than those dedicated
to the CW240.
• Do not use a clamp-on probe for a non-insulated conductor.
v
1
N
v
2
v
3
L L
1
CH
H
L
H
L
H
V INPUT
V INPUT
600V
600V
MAX MAX
TERM
INALS
600V M
AX
TERMINALS 600V MAX
TO EA
R
O EAR
TH TH
L
2
H
L
CH
CH
1
H
L
CH
CH
CA
CA
T.
LOGIC NIPUT
LOGIC NIPUT
STAR
T/ST
OP
5.5V M
AX
5.5V MAX
L
H
L
H
LOGIC NIPUT
LOGIC NIPUT
ST STAR
T/ST
OP OP
5.5V M
AX
5.5V MAX
Clamp-on current probe
Ring markers
<1>
<2>
●
Use of Ring Markers
• When using multiple clamp-on probes, attach ring markers (four colors) to the
probes. This allows inputs to be identified. Attach ring markers of the same
color to the current probe side <1> and connector side <2> of the cable of a
clamp-on probe.
• When attaching ring markers, exercise care not to damage the clamp-on
probes.