Conrad Multi 300 Operating Instructions Manual

The Conrad Multi 300 is a versatile multi-function tester designed for electrical diagnostics, featuring voltage detection, continuity testing, resistance measurement, and basic functionality checks. It operates on standard batteries, includes a digital display, test leads, protective holster, and auto-ranging capabilities. Below are key sections for safety, features, operation, measurement procedures, maintenance, and troubleshooting.

1. Features at a Glance 2. Safety Instructions 3. Initial Setup 4. Specifications 5. Controls and Display 6. Measurement Procedures 7. Function Selection Guide 8. Battery Replacement 9. Care & Storage 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Digital LCD display, Function selector dial, Test lead inputs (COM and VΩmA), Hold button, Data hold function, Auto power-off, Low battery indicator, Overload protection.

Feature	Description
Voltage Measurement	AC/DC voltage up to 600V
Continuity Test	Audible buzzer for circuit continuity
Resistance Measurement	Measures resistance up to 2MΩ
Diode Test	Checks diode forward voltage drop
Battery Test	Tests standard battery voltages
Auto-ranging	Automatically selects appropriate measurement range
Data Hold	Freezes display reading
Overload Protection	Protects against voltage spikes
Low Battery Indicator	Shows when batteries need replacement
Protective Holster	Rubber case for drop protection

Safety Instructions

Read all instructions before use. Always follow electrical safety protocols.

Do not exceed rated voltage (600V AC/DC).
Use proper personal protective equipment when working with live circuits.
Ensure test leads are in good condition before use.
Do not use the tester in wet or damp conditions.
Disconnect power before measuring resistance or continuity.

WARNING! Electric shock hazard. Use extreme caution when measuring live circuits. Never touch exposed metal parts of test leads.

Initial Setup

Prepare the tester for first use.

Install batteries: Open battery compartment, insert 2 AAA batteries observing polarity.
Connect test leads: Insert black lead into COM jack, red lead into VΩmA jack.
Function selection: Rotate selector dial to desired measurement function.
Power on: The tester powers on automatically when dial is rotated from OFF position.

CAUTION! Verify battery installation is correct before use. Incorrect polarity may damage the tester.

Specifications

Display: 3½ digit LCD, 2000 count
DC Voltage: 200mV to 600V, ±(0.5%+2 digits)
AC Voltage: 200V to 600V, ±(1.2%+3 digits)
Resistance: 200Ω to 2MΩ, ±(0.8%+2 digits)
Continuity: Audible buzzer below 50Ω
Diode Test: Test current 1mA, open circuit voltage 2.8V
Power Supply: 2 x 1.5V AAA batteries
Auto Power-off: Approximately 15 minutes of inactivity
Operating Temperature: 0°C to 40°C (32°F to 104°F)
Dimensions: 126mm x 70mm x 25mm

Controls and Display

Front Panel: Function selector dial, LCD display, HOLD button, Test lead jacks.

Display Symbols: AC/DC indicators, Low battery, Overload (OL), Data hold (H), Decimal points.

Function Selector Positions: OFF, V⎓ (DC voltage), V~ (AC voltage), Ω (resistance), ))) (continuity), diode symbol, battery test.

HOLD Button: Press to freeze current reading; press again to resume live measurement.

Measurement Procedures

Voltage: Select V⎓ or V~, connect leads in parallel with circuit. Resistance/Continuity: Select Ω or )))), ensure circuit is de-energized, connect leads across component.

Always start with highest range if manual ranging is required.
For AC measurements, note that reading shows RMS value.
For continuity testing, buzzer sounds when resistance is below 50Ω.
For diode testing, red lead to anode, black to cathode; typical reading 0.5V to 0.8V.

Tip: Ensure test leads make good contact with test points for accurate readings.

Function Selection Guide

Use the selector dial to choose measurement function.

DC Voltage (V⎓): For batteries, DC power supplies, automotive systems.
AC Voltage (V~): For household outlets, AC power lines.
Resistance (Ω): For resistors, wiring, circuit board traces.
Continuity ()))): For checking fuses, switches, wire connections.
Diode Test: For checking diodes, LED polarity.
Battery Test: For 1.5V and 9V batteries under load.

WARNING! Never rotate selector dial while test leads are connected to a live circuit. Always return to OFF position when not in use.

Battery Replacement

Replace batteries when low battery indicator appears.

Turn selector dial to OFF position and disconnect test leads.
Remove screw from battery compartment cover.
Replace both AAA batteries with new ones, observing correct polarity.
Replace cover and secure screw.

CAUTION! Use only fresh batteries of the same type. Do not mix old and new batteries.

Care & Storage

Clean with dry cloth only. Store in protective case when not in use.

CAUTION! Do not expose to extreme temperatures, moisture, or direct sunlight for extended periods.

Regulatory Information

Complies with relevant electrical safety standards. CE marked for European market. Copyright © Conrad Electronic SE. For technical support, visit www.conrad.com or contact customer service at +49 (0) 9243 50-0.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No display	Dead batteries	Replace batteries with fresh ones.
Inaccurate readings	Weak batteries	Replace batteries; check test lead connections.
Display shows "OL"	Overload/out of range	Select higher range or check circuit voltage.
Continuity buzzer not sounding	High resistance/open circuit	Check circuit continuity; resistance may be above 50Ω.
Tester turns off unexpectedly	Auto power-off activated	Rotate selector dial to OFF then back to desired function.

Reset: Remove batteries for 30 seconds, then reinstall.

Service: +49 (0) 9243 50-0; www.conrad.com