Extech MN15A Operating Manual

User's Guide

Mini Digital Multimeter

Model MN15A

A

Introduction

Congratulations on your purchase of the Extech MN15A MultiMeter. The MN15A offers
AC/DC Voltage, AC/DC Current, Resistance, Diode, and Continuity testing plus Type K
thermocouple temperature measurements. Proper use and care of this meter will provide
many years of reliable service.

Safety

This symbol adjacent to another symbol, terminal or operating device
indicates that the operator must refer to an explanation in the Operating
Instructions to avoid personal injury or damage to the meter.

WARNING

CAUTION

MAX
600V

SAFETY INSTRUCTIONS

This meter has been designed for safe use, but must be operated with caution. The rules
listed below must be carefully followed for safe operation.

1. NEVER apply voltage or current to the meter that exceeds the specified maximum:

Function Maximum Input

VDC or VAC 600VAC and VDC

VDC or VAC 200mV range 200Vrms

mA AC/DC 200mA 250V fast acting fuse

A AC/DC 10A 250V fast acting fuse

Resistance, Continuity 250Vrms for 15 sec. max.

2. USE EXTREME CAUTION when working with high voltages.

3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth ground.

4. NEVER connect the meter leads across a voltage source while the function switch is in the current,
resistance, or diode mode. Doing so can damage the meter.

5. ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistance
or diode tests.

6. ALWAYS turn off power and disconnect test leads before opening the covers to replace the fuse or battery.

7. NEVER operate the meter unless the back cover and the battery and fuse covers are in place and fastened
securely.

8. If the equipment is used in a manner not specified by the manufacturer, the protection provided by the
equipment may be impaired.

This WARNING symbol indicates a potentially hazardous situation, which
if not avoided, could result in death or serious injury.

This CAUTION symbol indicates a potentially hazardous situation, which
if not avoided, may result damage to the product.

This symbol advises the user that the terminal(s) so marked must not be
connected to a circuit point at which the voltage with respect to earth
ground exceeds 600V.

This symbol adjacent to one or more terminals identifies them as being
associated with ranges that may, in normal use, be subjected to
particularly hazardous voltages. For maximum safety, the meter and its
test leads should not be handled when these terminals are energized.

This symbol indicates that a device is protected throughout by double
insulation or reinforced insulation.

Input Protection Limits

(for 30 seconds max. every 15 minutes.)

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MN15A V1.1 02/09

Controls and Jacks

1. LCD display

2. Rotary function switch

3. 10 ampere test lead jack

4. Test lead jack for voltage, milliamp,
resistance/continuity, diode and temperature functions

5. COM test lead jack

6. Battery compartment (rear)

SYMBOLS

•))) Continuity Diode

AC DC

6

M megga (10

k kilo (10

A Amps Ω Ohms

BAT Battery test °C Degrees Celsius

°F Degrees Fahrenheit Low battery indicator

) (ohms) m milli (10-3) (volts, amps)

3

) (ohms) V Volts

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MN15A V1.1 02/09

Operating Instructions

WARNING: Risk of electrocution. High-voltage circuits, both AC and DC, are very
dangerous and should be measured with great care.

NOTE: On some low AC and DC voltage ranges, with the test leads not connected to a
device, the display may show a random, changing reading. This is normal and is caused
by the high-input sensitivity. The reading will stabilize and give a proper measurement
when connected to a circuit.

AC VOLTAGE MEASUREMENTS

WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the

live parts inside some 240V outlets for appliances because the contacts are recessed deep
in the outlets. As a result, the reading may show 0 volts when the outlet actually has voltage
on it. Make sure the probe tips are touching the metal contacts inside the outlet before
assuming that no voltage is present.

CAUTION: Do not measure AC voltages if a motor on the circuit is being switched ON or
OFF. Large voltage surges may occur that can damage the meter.

1. Set the function switch to the 600 VAC position.

2. Insert the black test lead banana plug into the negative COM jack.
Insert red test lead banana plug into the positive V jack.

3. Touch the black test probe tip to the neutral side of the circuit.

4. Touch the red test probe tip to the “hot” side of circuit.

5. Read the voltage in the display.

6. If the reading is less than 200V, switch to the 200V range to improve
resolution.

DC VOLTAGE MEASUREMENTS

CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or

OFF. Large voltage surges may occur that can damage the meter.

1. Set the function switch to the highest 600VDC position.

2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive V jack.

3. Touch the black test probe tip to the negative side of the circuit. Touch
the red test probe tip to the positive side of the circuit.

4. Read the voltage in the display.

5. If the reading is less than the maximum of a lower range, switch to that
range to improve resolution.

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