UEi Test Instruments M110A - Manual (Page 2)

Introduction
The M110A, in addition to high-resolution voltage and ohms scales
needed for electrical troubleshooting also includes the features that
help you maintain and troubleshoot HVAC/R systems. Features like DC
millivolts and microamps let you troubleshoot flame safeguard circuits
and the millivolts function helps you evaluate heat anticipators.
Features include
• 21 ranges
• 600 Volts AC and 300 Volts DC
• 2 Megohm resistance
• High resolution DC µA for flame safeguard testing
• DC millivolt scale allows use of adapters
• Color-coded and mirrored scale plate
Safety Notes
Before using this meter, read all safety information carefully. In
this manual the word "WARNING" is used to indicate conditions
or actions that may pose physical hazards to the user. The word
"CAUTION" is used to indicate conditions or actions that may
damage this instrument.
• Always follow industry standard safety practices including protective
clothing, gloves and safety glasses when appropriate
• Do not attempt to measure any voltage that exceeds the
ca t e g o ry based rating of this meter
• Do not attempt to use this meter if either the meter or the test
leads have been damaged. Turn it in for repair at a qualified
repair facility
• Ensure meter leads are fully seated by making a quick continuity
check of the leads prior to making voltage measurements
• Keep your fingers away from the test lead’s metal probe
contacts when making measurements. Always grip the leads behind
the finger guards molded into the probes
• Use a current clamp adapter when measuring current that may
exceed 10 amps. See the accessories in UEi’s full-line ca t a l o g
• Do not open the meter to replace batteries or fuses while the
probes are connected
WARNING!
Exceeding the specified limits of this meter is dangerous and can
expose the user to serious or possibly fatal injury.
• Voltages above 60 volts DC or 25 volts AC may constitute a
serious shock hazard
• Always turn off power to a circuit (or assembly) under test
before cutting, unsoldering, or breaking the current path -
Even small amounts of current can be dangerous
• Always disconnect the live test lead before disconnecting the
common test lead from a circuit
• In the event of electrical shock, ALWAYS bring the victim to
the emergency room for evaluation, regardless of the victim’s
apparent recovery - Electrical shock can cause an unstable heart
rhythm that may need medical attention
• Higher voltages and currents require greater awareness of
physical safety hazards - Before connecting the test leads; turn
off power to the circuit under test; set the meter to the desired
function and range; connect the test leads to the meter first, then
to the circuit under test. Reapply power
• If any of the following indications occur during testing, turn
off the power source to the circuit under test:
• Arcing
• Flame
• Smoke
• Extreme Heat
• Smell of Burning Materials
• Discoloration or Melting of Components
CAUTION!
Do not attempt to re m ove the meter leads from the circuit under test.
The leads, the meter, or the circuit under test may have degraded to
the point that they no longer provide protection from the voltage and
c u r rent applied. If any of these erroneous re a d i n gs are observed,
disconnect power immediately and recheck all settings and connections.
C o n t rols and Indicators
1. Selector Switch: Is used to select the circuit function and range.
It is good practice to start with the highest range setting of the
“SELECTOR” switch for a particular function if the magnitude of
the function is unknown.
2. Ω ADJ: The “Ω ADJ” control is used on the OHMS function. The
purpose of this control is to calibrate the M110A on the particular
range selected (Rx1, Rx10, etc.)
3. Mechanical Zero Adjust: Is a plastic screw located on the meter
face just beneath the “LOCK” switch. This adjustment is used to set
the pointer to the zero index mark at the left side of the scale plate.
4. Input Jacks:
COM (-): The black test lead is used to connect this jack to the
negative, or common, side of the circuit test.
VΩM (+): The red test lead is used to connect this jack to the
positive side of the circuit test.
DC 12 0 0 V: This jack is used for the 0 - 1200 V DC (0 - 12 K V DC with
optional probe) range of the M110A. The red (positive) test lead is
connected to this jack.
M110A-MAN P. 1
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