Hioki CM4375-50 1000 A AC/DC True RMS Clamp Meter

A slim-jaw AC/DC clamp meter that also works as a multimeter

The Hioki CM4375-50 is a true RMS AC/DC clamp meter with a 1000 A current range and a slim 34 mm jaw. It is the 1000 A member of Hioki’s CM437x family, alongside the 600 A CM4371-50 and the 2000 A CM4373-50, and it combines the clamp with a full multimeter: AC, DC and AC+DC voltage, resistance, continuity and diode checks, capacitance, frequency, temperature with a type K thermocouple, inrush current and DC power.

The slim jaw is designed for crowded wiring. Hioki states the jaw is rated for measurement in dust and water droplets (IP54 when measuring the current of an insulated conductor, IP20 otherwise), the working temperature range is -25 to 65 degC, and the measurement category is CAT IV 600 V and CAT III 1000 V. With the optional DC high voltage probe P2010 the category rises to CAT IV 1000 V / CAT III 2000 V and the DC voltage range extends to 2000 V, which suits solar PV installations with high string voltages. Automatic AC/DC detection, MAX / MIN / AVG, a low-pass filter and automatic or manual data hold are included, and the display updates five times a second.

With the optional Wireless Adapter Z3210 the clamp meter sends readings by Bluetooth to the free GENNECT Cross app or into an Excel file.

Technical specifications

Where the 1000 A AC/DC model fits

An AC/DC clamp is needed for battery strings, DC drives, solar combiner boxes, EV charging equipment and any circuit where DC current flows, none of which an AC-only clamp can read. The CM4375-50 covers 1000 A, which fits most distribution boards and PV string combiners; for busbars and large feeders the CM4373-50 offers 2000 A with a 55 mm jaw, and the CM4371-50 offers a finer 20 A resolution range up to 600 A. The CM4141-50 is the AC-only 2000 A alternative.

Hioki lists the measured items so that buyers can compare directly: true RMS measurement for distorted waveforms, which averaging clamps misread; inrush current capture; a peak detection time width of 1 ms; and measurement of DC power in combination with voltage. The manual also describes a wire-wrapping method to raise the reading of small currents.

What to confirm before ordering

Confirm the maximum conductor size against the 34 mm jaw and the highest current you expect against the 1000 A range. State whether you need the P2010 DC high voltage probe for 1500 V or 2000 V solar work, the Z3210 wireless adapter, a type K thermocouple, a carrying case and test leads. Hioki guarantees accuracy for one year, so mention any calibration certificate needed. The document attached is the instruction manual covering the CM4371-50, CM4373-50 and CM4375-50, and the data above are the CM4375-50 values.

How the Hioki CM4375-50 works

The clamp jaw senses the current flowing in a single conductor. Voltage, resistance and the other values are measured through the test leads. The meter shows the result on its display and holds it on request.

Where the CM4375-50 is used

• Distribution panel checks
• Motor current measurement
• Crowded wiring
• Solar string checks with the optional probe
• Inrush current checks

Selection checklist for the CM4375-50

• Current range
• Jaw size
• AC and DC need
• Voltage range
• Temperature probe
• Wireless adapter
• High voltage probe
• Battery type

Installation, commissioning and maintenance notes for the CM4375-50

Check the leads and the jaw before each use. Clamp around one conductor only and keep clear of live parts. Replace the batteries when the display warns and store the meter dry.

Requesting a quotation for the Hioki CM4375-50

Please send the current range and the accessories needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

CM4375-50 meter type

It is a true RMS AC/DC clamp meter.

CM4375-50 maker

It is made by Hioki.

CM4375-50 current range

The current range is 1000 A.

CM4375-50 family position

It sits between the 600 A CM4371-50 and the 2000 A CM4373-50.

CM4375-50 jaw

The jaw is slim at 34 mm.

CM4375-50 multimeter functions

It also works as a full multimeter.

CM4375-50 voltage

It measures AC, DC and AC+DC voltage.

CM4375-50 resistance

Resistance is measured up to 6 MOhm.

CM4375-50 other checks

Continuity, diode, capacitance and frequency checks are included.

CM4375-50 temperature

Temperature is read with a type K thermocouple from minus 40 to 400 degrees C.

CM4375-50 inrush current

It measures inrush current.

CM4375-50 DC power

It also measures DC power.

CM4375-50 optional probe

The optional P2010 high voltage probe extends the DC range to 2000 V.

CM4375-50 solar use

The probe suits solar installations with high string voltages.

CM4375-50 auto detection

Automatic AC/DC detection is included.

CM4375-50 data functions

It has MAX, MIN and AVG, a low-pass filter and data hold.

CM4375-50 display update

The display updates five times a second.

CM4375-50 wireless option

The optional Z3210 adapter sends readings by Bluetooth.

CM4375-50 app

Readings go to the free GENNECT Cross app or into an Excel file.

CM4375-50 working temperature

It works from minus 25 to 65 degrees C.

CM4375-50 batteries

It runs on two AAA alkaline batteries for about 40 hours.

CM4375-50 battery life with wireless

Battery life is about 20 hours with the Z3210 communicating.

Meter records for the CM4375-50

Record the readings taken, the date and the leads used.

Choosing the right CM4375-50 accessories

Choose the probe and the wireless adapter from the measurement task.

Documents and quotation

For comparison with other clamp meters, see the Fluke 376 FC true-RMS AC/DC clamp meter and the portable test and measurement category. Send the model, accessories and quantity for a quotation from Seven Star LLC.