Mastercool 52240-A — Digital Clamp Meter 600A AC/DC Multimeter with Data Hold & Peak Hold

Digital Clamp Meter — Versatile Electrical Diagnostic Tool

Mastercool's Digital Clamp Meter is a completely portable hand-held test instrument which provides versatile measuring capabilities. This unit is ideal for maintenance and inspection work on all types of electrical equipment. Essential for HVAC/R technicians who need to diagnose electrical issues, measure current draw, and verify proper system operation.

Complete Kit Includes

• Digital Clamp Meter: 52240-A main unit
• 1 Pair of Test Probes: For voltage and resistance measurements
• Soft Carry Case: Protective storage and transport
• 9V Battery: Ready to use out of the box

Key Features

• AC Current Measurement: 10mA to 600A range
• AC Voltage: 100mV to 600V
• DC Voltage: 1V to 600V
• Resistance: 100mΩ to 20KΩ
• Frequency Count: 10Hz to 2KHz
• Continuity Check: < 100Ω with audio tone
• Diode Check: Forward or reverse testing
• Data Hold Function: Freeze display for recording measurements
• Peak Hold Function: Capture peak values
• 40mm Conductor Diameter: Accommodates large cables
• Automatic Polarity: Negative polarity indication
• Single Range Switch: Easy operation
• Over Range Indication: Clear display when limits exceeded
• Low Battery Warning: "BT" appears in last 20% of battery life
• Long Battery Life: Up to 200 hours with alkaline battery

Technical Specifications

• Model: 52240-A
• Display: 3-1/2 digit LCD (1999 count) with annunciators
• Sampling Rate: 2.5 times per second
• Conductor Diameter: 40mm maximum
• Polarity: Automatic "–" negative polarity indication
• Range Selection: All ranges measured by single range switch operation
• Over Range Indication: Highest digit of (1) or (-1) displayed
• Low Battery Indication: "BT" appears on display in last 20% of battery life
• Battery Life: Up to 200 hours with alkaline battery
• Power Requirements: Single 9V battery
• Operating Temperature: 0°C to 40°C (32°F to 104°F) below 80% RH
• Storage Temperature: -10°C to 60°C (14°F to 140°F) below 80% RH
• Dimensions: 208 x 65 x 31mm (8.2" x 2.6" x 1.3")
• Weight: 308g (10.9 oz) including battery
• SKU: 52240-A
• HS Code: 84189910

Measurement Ranges

AC Current:

• Range: 10mA to 600A
• Ideal for measuring compressor current draw, fan motor current, and total system current

AC Voltage:

• Range: 100mV to 600V
• Measure mains voltage, control voltage, and transformer outputs

DC Voltage:

• Range: 1V to 600V
• Test control circuits, sensors, and DC power supplies

Resistance:

• Range: 100mΩ to 20KΩ
• Check continuity, measure coil resistance, verify connections

Frequency:

• Range: 10Hz to 2KHz
• Verify AC frequency and diagnose inverter outputs

Applications

• HVAC/R compressor current measurement
• Fan motor current testing
• Electrical troubleshooting and diagnostics
• Mains voltage verification
• Control circuit testing
• Continuity checking
• Resistance measurements
• Frequency verification
• Diode and component testing
• Electrical installation inspection

Why Choose the 52240-A?

• Versatile Measurements: AC/DC voltage, AC current, resistance, frequency, continuity, diode test
• Wide Current Range: 10mA to 600A covers most HVAC/R applications
• 40mm Jaw Opening: Accommodates large cables and multiple conductors
• Data Hold: Freeze display for recording in difficult positions
• Peak Hold: Capture inrush current and peak values
• Audio Continuity: Hands-free continuity testing with tone
• Long Battery Life: Up to 200 hours operation
• Compact & Portable: Only 308g with protective carry case
• Easy to Read: Large LCD display with clear annunciators
• Complete Kit: Includes probes, case, and battery
• Professional Quality: Mastercool reliability

Perfect For

• HVAC/R service technicians
• Electrical contractors
• Maintenance engineers
• Commercial refrigeration technicians
• Automotive A/C specialists
• Workshop and field service operations
• Electrical troubleshooting and diagnostics

Common HVAC/R Measurements

Compressor Current Draw:

• Clamp around compressor power cable
• Measure running current (RLA - Rated Load Amps)
• Compare to nameplate specifications
• High current indicates mechanical problems or electrical issues
• Low current may indicate refrigerant undercharge

Fan Motor Current:

• Measure condenser fan and evaporator fan current
• Verify motors are operating within specifications
• Detect bearing wear or mechanical binding

Total System Current:

• Measure total current draw at disconnect
• Verify system is within circuit breaker rating
• Calculate actual power consumption

Control Voltage:

• Use test probes to measure 24VAC control circuits
• Verify transformer output
• Test thermostat circuits

Data Hold & Peak Hold Functions

Data Hold: Press the hold button to freeze the current reading on the display. Useful when taking measurements in awkward positions where the display is difficult to see, or when you need to record the value.

Peak Hold: Captures and displays the peak (maximum) value during a measurement period. Essential for measuring compressor inrush current or identifying intermittent electrical spikes.

Continuity Check with Audio Tone

The continuity function provides an audible tone when resistance is below 100Ω, allowing hands-free continuity testing. Ideal for:

• Verifying wire connections
• Testing fuses and circuit breakers
• Checking switch contacts
• Tracing circuits
• Identifying short circuits

Safety & Accuracy

Accuracies are ± (% reading + number of digits) at 23°C ± 5°C below 80% RH. Always observe proper electrical safety procedures when using this meter:

• Never exceed the maximum rated voltage or current
• Ensure proper insulation on test leads
• De-energise circuits before making resistance measurements
• Use appropriate personal protective equipment
• Follow local electrical safety regulations

Display Annunciators

The LCD display includes the following indicators:

• P: Peak Hold mode active
• H: Data Hold mode active
• –: Negative polarity
• BT: Low battery warning (last 20% of battery life)
• ~: AC measurement
• V: Voltage
• A: Current (Amperes)
• Ω: Resistance (Ohms)
• KΩ: Kilohms
• KHz: Kilohertz
• Decimal point: Indicates measurement scale

Maintenance

• Battery Replacement: Replace 9V battery when "BT" indicator appears
• Storage: Store in protective carry case in clean, dry environment
• Cleaning: Wipe exterior with clean, dry cloth
• Jaw Cleaning: Keep clamp jaws clean for accurate current measurements
• Test Leads: Inspect test leads regularly for damage or wear

Professional Quality: Mastercool diagnostic tools are built to professional standards for accurate, reliable performance in demanding HVAC/R and electrical service environments. The 52240-A Digital Clamp Meter provides versatile measuring capabilities essential for electrical troubleshooting and system diagnostics.