AEMC MiniFlex® HF Flexible AC Current Probes

User Manual for Models MF 300-10-2-10 HF and MF 3000-14-1-1 HF

Brand: AEMC Instruments (Chauvin Arnoux Group)

1. Introduction

Thank you for purchasing an AEMC® Instruments MiniFlex® Flexible AC Current Probe Model MF 300-10-2-10 HF or Model MF 3000-14-1-1 HF. For best results and safety, read this manual carefully and comply with the precautions. This product should only be used by qualified and trained operators.

1.1 International Electrical Symbols

[Double/Reinforced Insulation Symbol]: Signifies that the instrument is protected by double or reinforced insulation.
⚠️ CAUTION - Risk of Danger!: Indicates a WARNING. Refer to the user manual before operation.
⚡ [Electric Shock Symbol]: Indicates a risk of electric shock. The voltage at marked parts may be dangerous.
[Type B Current Sensor Symbol]: Refers to a type B current sensor as per IEC 61010-2-032. Application or withdrawal not authorized on conductors carrying dangerous voltages.
ℹ️ [Information Symbol]: Indicates important information to acknowledge.
CE: This product complies with the Low Voltage & Electromagnetic Compatibility European directives.
? [Battery Symbol]: Battery.
[Recycling Symbol]: In the European Union, this product is subject to a separate collection system for recycling electrical and electronic components in accordance with directive WEEE 2012/19/EU.

1.2 Definition of Measurement Categories

CAT IV: Corresponds to measurements performed at the primary electrical supply (< 1000 V). Example: primary overcurrent protection devices, ripple control units, and meters.
CAT III: Corresponds to measurements performed in the building installation at the distribution level. Example: hardwired equipment in fixed installation and circuit breakers.
CAT II: Corresponds to measurements performed on circuits directly connected to the electrical distribution system. Example: measurements on household appliances and portable tools.

1.3 Precautions for Use

These safety warnings ensure the safety of personnel and proper operation of the instrument.

Read this instruction manual completely and follow all safety information before use or service.
Safety is the operator's responsibility. Use only by qualified personnel with applicable safety precautions.
Wear protective clothing and gloves as required.
Use caution on any circuit; high voltages and currents may pose a shock hazard.
Read the safety specifications section before use. Never exceed maximum voltage ratings.
ALWAYS de-energize the circuit before wrapping the MiniFlex® around bare conductors, bus bars, or near live parts. Do not wrap on live conductors.
ALWAYS connect the electronic module to the display device before wrapping the MiniFlex® around the sample.
ALWAYS inspect the module, sensor, cable, and terminals before use. Replace defective parts immediately with factory parts.
NEVER use the MiniFlex® on electrical conductors rated above 1000 V CAT III; 600V CAT IV.

1.4 Receiving Your Shipment

Upon receiving your shipment, verify contents against the packing list and notify your distributor of any missing items. If the equipment appears damaged, file a claim immediately with the carrier and notify your distributor with a detailed description of the damage. Save the damaged packing container.

1.5 Ordering Information

Models:

MiniFlex® 30/300 A, 10 in, 100 mV/10 mV/A High Frequency (for use with any BNC Oscilloscope): Cat. #2126.84
MiniFlex® 3000 A, 14 in, 1 mV/A High Frequency (for use with any BNC Oscilloscope): Cat. #2126.86

Both models include a 9V battery and a user manual.

1.5.1 Accessories and Replacement Parts

Adapter - BNC (female) / 4 mm Banana (male): Cat. #2119.94

Order accessories and replacement parts online at www.aemc.com/store.

2. Product Features

2.1 Description

The MiniFlex® HF is a compact flexible AC current transformer with a flexible sensor and an electronic module, designed for measurements from 5 Hz to 1 MHz. The flexible sensor allows measurements on conductors where standard clamp-on probes are difficult to use, such as in confined spaces or around irregular shapes. It is lightweight, uses an air core (no magnetic cores), presents virtually no load to the system, and offers low phase shift and excellent frequency response (5 Hz to 1 MHz at -3 dB). It is insulated for 1000 V CAT III; 600 V CAT IV and is CE marked. The MiniFlex® HF provides an mV output proportional to the measured current, suitable for oscilloscopes, DMMs, data loggers, and power/harmonic meters. TRMS measurements are possible when connected to a TRMS meter. It is insensitive to DC currents, measuring only the AC component. The flexible sensor is available in 6-inch and 10-inch lengths.

2.2 Features

Measures from (0.5 to 300) ARMS
Accuracy: 1% of Reading ± 0.3 A
Supports TRMS measurements when connected to a TRMS instrument.
No core saturation or damage if overloaded.
9 V battery for typical 140 hours of continuous operation.
1 MHz frequency response.
Low phase shift for power measurements.
Insensitive to DC; measures only the AC component on DC + AC signals.
Excellent linearity.
Lightweight design.
Sensor is resistant to oils and aliphatic hydrocarbons.
Complies with EN 61010, 1000 V CAT III; 600 V CAT IV; CE Mark.

2.3 Control Features

Figure 1 illustrates the components:

1. Flexible sensor 5 mm Ø
2. Sensor opening device
3. Shielded cord
4. BNC output connector
5. Green ON/OFF indicator
6. Range selection switch
7. Optional BNC (female) / Banana (male) connector

3. Specifications

Reference Conditions

Quantity of Influence	Reference Values
Temperature	23 ± 5° C
Relative humidity	(20 to 75) % RH
Frequency of the signal measured	(40 to 400) Hz
Type of signal	Sinusoidal
External electric field	< 1 V/m
External DC magnetic field (earth field)	< 40 A/m
External AC magnetic field	None
Position of the conductor	Centered in the measurement coil
Shape of the measurement coil	Nearly circular
Input impedance of the display device connected to housing	≥ 1MΩ

Electrical Specifications

MODEL	MF 300-10-2-10 HF	MF 3000-14-1-1 HF
Range	30/300 A	3000 A
Signal Output	100 mV/10 mV/A	1 mV/A
Frequency Range	5 Hz to 1 MHz @ -3db
Frequency Limitation	none
Influence Of Conductor Positioning	1.5 % typical, 3 % max
Influence Of Conductor Positioning In Sensor Against Handle	4% typical, 6% max
External Conductor Influence	35dB to 40dB on contact
Accuracy	± 1% +0.3 A
Common Mode Rejection	100dB typical, 80dB min
Max peak factor (1) at I nominal	1.5
Residual noise at I = 0 (ARMS) (2)	0.3 A
Max phase shift at 1kHz (°)	1.5
Max offset voltage (mVDC)	± 4.5
Max output voltage (Vpeak)	5
Output impedance (kΩ)	1
Power Source	9V alkaline battery (6LF22)
Battery Life	140 hrs continuous operation or 10,000 one minute measurements
Battery Indicator	When Green LED starts blinking, remaining life is approx 8 hours; When LED is OFF, the battery needs to be replaced.

(1): Peak factor PF = Vpeak/VRMS

(2): The residual noise affects the measurement uncertainty according to the formula: global uncertainty = √((I measured x 0.01)² + (residual noise)²) / I measured (I measured ≠ 0). If the current measured is zero, the uncertainty is equal to the residual noise.

Mechanical Specifications

MODEL	MF 300-10-2-10 HF	MF 3000-14-1-1 HF
Module Output	Coaxial cable terminated by an insulated female BNC connector
Module Dimensions	4.0 x 2.5 x 1.1 in (103 x 64 x 28 mm)
Module Weight	7 oz (200 g)
Sensor Diameter	5 mm Ø	5 mm Ø
Sensor Length	10 in (250 mm)	14 in (355 mm)
Max Conductor Size	2.95 in (70 mm)	3.93 in (100 mm)
Connection Cable Length	6.5 ft (2 m)
Flammability Rating	Sensor: UL94V0 Housing: UL94V2
Drop Test	Per IEC 68-2-32
Vibration	Per IEC 68-2-6
Mechanical Shock	Per IEC 68-2-27
Weatherproofing	IP 50

Environmental Specifications

Parameter	Value
Operating Temperature Range	(14 to 131) °F (-10 to +55) °C
Storage Temperature Range	(-40 to 158) °F (-40 to +70) °C
Influence of Temperature	Sensor: (-10 to 100) °C: < 0.5 % of Reading per 10 °C; Module: (-10 to 55) °C: < 0.5 % of Reading per 10 °C
Relative Humidity	(10 to 90) % RH: 0.1% typical, 0.3 % max
Altitude	Operating: (0 to 2000) m, working voltage derating above; Non-operating: (0 to 12,000) m

Safety Specifications

Parameter	Value
Double Insulation	Yes, per IEC 1010-2-32
CE Rated	Yes
Safety Rating	EN 61010, 1000V CAT III; 600V CAT IV
Pollution Level	2
Immunity and Emission	Industrial environment
Electromagnetic Compatibility	Satisfies the EMC and LVD directives required for CE marking and product standard IEC 61326-1 (Ed. 97) + A1 (Ed. 98)

Specifications are subject to change without notice.

3.1 Typical Response Curves

3.1.1 Frequency Error

Model MF 300-10-2-10 HF Diameter 70 mm

300 A Range:

Graph showing frequency error for the 300 A range. The x-axis represents frequency from 1 Hz to 100 kHz (logarithmic scale). The y-axis represents percentage error from -10% to 30%. The error is approximately 25% at 1 Hz, decreases sharply to around 5% at 10 Hz, and then stabilizes to approximately 0% from 100 Hz to 100 kHz.

Model MF 3000-14-1-1 HF Diameter 100 mm

3000 A Range:

Graph showing frequency error for the 3000 A range. The x-axis represents frequency from 1 Hz to 100 kHz (logarithmic scale). The y-axis represents percentage error from -1% to 1%. The error is approximately 1% at 1 Hz, decreases to around 0.2% at 10 Hz, stays close to 0% between 100 Hz and 10 kHz, and then drops to approximately -0.5% at 100 kHz.

4. Operation

4.1 Compatibility

The MiniFlex® is compatible with any Oscilloscope, AC voltmeter, or other voltage measuring instrument with an input impedance greater than 1 MΩ. For best overall accuracy, use with an Oscilloscope set to AC mode with an accuracy of 0.75% or better.

4.2 Tips for Making Precise Measurements

When using with an Oscilloscope, select the range that provides the best resolution to avoid measurement errors.
For best results, select the highest MiniFlex® output signal possible and the most sensitive meter range for this output.
Ensure the Oscilloscope or measuring instrument can accurately measure mVAC.
For best accuracy, center the MiniFlex® around the conductor being measured.
Overall measurement accuracy is the sum of the MiniFlex® accuracy and the displaying instrument accuracy.

4.3 Making Measurements

Connect the electronic module to the AC Volt range of an Oscilloscope input or measuring instrument. Select the highest range on the MiniFlex®.

Press the sensor's yellow opening device to open the flexible coil. Wrap the coil around the conductor to be tested. If possible, within range, select the lowest range to obtain the best resolution.

Do not exceed the specified current range for the output.

Read the displayed value on the Oscilloscope and divide it by the range selected (e.g., if reading = 2.59 V with the 10 mV/A output range, the current is 2590 mV ÷ 10 = 259 A).

For best accuracy, carefully center the conductor inside the flexible core, and if possible, avoid proximity to other conductors that may create noise and interference (particularly near the latch).

5. Maintenance

5.1 Warning

For maintenance, use only specified replacement parts.
To avoid electrical shock, do not attempt servicing unless qualified.
To avoid electrical shock and/or instrument damage, do not allow water or foreign agents into the case.
Turn the instrument OFF and disconnect from all circuits before opening the case.

5.2 Battery Replacement

Replace the battery when the green indicator flashes or remains off when the instrument is switched on.

Disconnect all connected items and set the switch to OFF.
Use a screwdriver to unscrew the two housing screws.
Replace the old battery with a new 9V alkaline or lithium battery (type 6LF22).
Close the housing securely and screw the screws back in.

5.3 Cleaning

Keep the sensor latch mating surfaces clean to prevent foreign matter from entering the closing.

The sensor can be gently cleaned with a soft cloth, soap, and water. Dry immediately after cleaning. Avoid water penetration into the electronic module.
Ensure the sensor, electronic module, and all leads are completely dry before further use.

5.4 Repair and Calibration

To ensure the instrument meets factory specifications, it is recommended to send it to the factory Service Center at one-year intervals for recalibration or as required by standards or internal procedures.

For instrument repair and calibration:

Contact the Service Center for a Customer Service Authorization Number (CSA#) by emailing repair@aemc.com. You will receive a CSA Form and other required paperwork. Return the instrument with the signed CSA Form. Write the CSA# on the outside of the shipping container. Specify if a standard calibration or a NIST-traceable calibration is required.

Ship To:
Chauvin Arnoux®, Inc. d.b.a. AEMC® Instruments
15 Faraday Drive ▪ Dover, NH 03820 USA
Phone: (800) 945-2362 (Ext. 360) / (603) 749-6434 (Ext. 360)
Fax: (603) 742-2346
E-mail: repair@aemc.com

(Or contact your authorized distributor.)

Contact them for costs of repair, standard calibration, and NIST-traceable calibration.

ℹ️ NOTE: You must obtain a CSA# before returning any instrument.

5.5 Technical Assistance

For technical problems or assistance with operation or application, contact the technical support team:

Chauvin Arnoux®, Inc. d.b.a. AEMC® Instruments
Phone: (800) 343-1391 (Ext. 351)
Fax: (603) 742-2346
E-mail: techsupport@aemc.com
www.aemc.com

5.6 Limited Warranty

The instrument is warranted for two years from the date of original purchase against manufacturing defects. This warranty is provided by AEMC® Instruments. It is void if the unit is tampered with, abused, or if the defect relates to service not performed by AEMC® Instruments.

Full warranty coverage and product registration are available at www.aemc.com/warranty.html.

What AEMC® Instruments will do: If a malfunction occurs within the warranty period, return the instrument for repair with warranty registration information or proof of purchase. AEMC® Instruments will repair or replace the faulty material at its discretion.

5.6.1 Warranty Repairs

To return an instrument for Warranty Repair:

First, email repair@aemc.com to request a Customer Service Authorization Number (CSA#) from the Service Department. You will receive a CSA Form and other required paperwork. Return the instrument with the signed CSA Form. Write the CSA# on the outside of the shipping container.

Return the instrument, postage or shipment prepaid to:
Chauvin Arnoux®, Inc. d.b.a. AEMC® Instruments
15 Faraday Drive, Dover, NH 03820 USA
Phone: (800) 945-2362 (Ext. 360) / (603) 749-6434 (Ext. 360)
Fax: (603) 742-2346
E-mail: repair@aemc.com

Caution: To protect against in-transit loss, insure your returned material.