User Manual

2.3 Connecting Clamps

Because it measures only voltage input, current is not measured directly by this

instrument.

Use a clamp that provides voltage output for current measurement.

Refer to "1.3 List of Input Modules, Cables, Probes and Clamp Combinations"

(⇒ p. 11) for compatible combinations of Hioki clamps and input modules.

Refer also to the clamp’s Instruction Manual for clamp-specific details.

Preparations for Using Clamps

2.3 Connecting Clamps

Connect the clamp-on sensors to the instrument first, and then to the

active lines to be measured. Observe the following to avoid electric shock

and short circuits.

• To avoid short circuits and potentially life-threatening hazards, never

attach the clamp to a circuit that operates at more than the maximum

rated voltage, or over bare conductors.

• Clamps should only be connected to the secondary side of a breaker, so

the breaker can prevent an accident if a short circuit occurs. Connec-

tions should never be made to the primary side of a breaker, because

unrestricted current flow could cause a serious accident if a short circuit

occurs.

• When the clamp sensor is opened, do not allow the metal part of the

clamp to touch any exposed metal, or to short between two lines, and do

not use over bare conductors.

To avoid electric shock when measuring live lines, wear appropriate pro-

tective gear, such as insulated rubber gloves, boots and a safety helmet.

• To prevent damage to the instrument and clamp, never connect or disconnect

a sensor while the power is on, or while the sensor is clamped around a con-

ductor.

• Be careful to avoid dropping the clamps or otherwise subjecting them to

mechanical shock, which could damage the mating surfaces of the core and

adversely affect measurement.

• Measurements are affected by the combined accuracy of this instrument and

the clamp.

• The measured value is displayed as voltage [V], although this can be

converted for display as current [A] using the Scaling function.

See "5.4 Converting Input Values (Scaling Function)" in the Instruction Manual

• In the following cases, scaling setup is necessary:

(1) When using a clamp with a voltage measurement input module other than

the Model 8940 F/V Unit

(2) When connecting a clamp to the Model 8940 F/V Unit without the Model

9318 or 9319 Conversion Cable

For details about connecting clamps to the Model 8940 F/V UNIT:

See "2.2.5 Connecting to the Model 8940 F/V Unit" (

⇒ p. 21).