Centech 59458 User manual

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Owner’s Manual & Safety Instructions
Save This Manual Keep this manual for the safety warnings and precautions, assembly,
operating, inspection, maintenance and cleaning procedures. Write the product’s serial number in the
back of the manual near the assembly diagram (or month and year of purchase if product has no number).
Keep this manual and the receipt in a safe and dry place for future reference. 22h
When unpacking, make sure that the product is intact
and undamaged. If any parts are missing or broken,
please call 1-888-866-5797 as soon as possible.
Copyright©2018 by Harbor Freight Tools®. All rights reserved.
No portion of this manual or any artwork contained herein may be reproduced in
any shape or form without the express written consent of Harbor Freight Tools.
Diagrams within this manual may not be drawn proportionally. Due to continuing
improvements, actual product may differ slightly from the product described herein.
Tools required for assembly and service may not be included.
Read this material before using this product.
Failure to do so can result in serious injury.
SAVE THIS MANUAL.

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SAFETY OPERATION MAINTENANCESETUP
WARNING SYMBOLS AND DEFINITIONS
This is the safety alert symbol. It is used to alert you to
potential personal injury hazards. Obey all safety messages
that follow this symbol to avoid possible injury or death.
Indicates a hazardous situation which, if not avoided,
will result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
Addresses practices not related to personal injury.
Table of Contents
Safety ..........................................3
Specifications ..............................5
Setup ...........................................6
Operation.....................................8
Maintenance...............................14
Warranty .....................................16

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SAFETYOPERATIONMAINTENANCE SETUP
IMPORTANT SAFETY INFORMATION
Safety Warnings and Precautions
Read all safety warnings and all instructions.
Failure to follow the warnings and instructions may result
in electric shock, fire and/or serious injury.
Save all warnings and instructions for future reference.
1. Electrical shock can cause death
or injury! NEVER TOUCH exposed
conductors of electricity.
2. Test cable voltages with care.
Only use one hand when securing
the clamp around cable.
3. Inspect the Meter before use. In
addition to a general inspection,
look specifically for:
a. Pay special attention to the
insulation protecting the connectors.
b. Check the leads for exposed metal,
damaged insulation, and continuity.
c. Replace damaged test lead
immediately, before use.
4. Do not use the Meter if:
a. The test lead is damaged
in any way.
b. The battery is low.
c. Near any explosive
gasses or fumes.
d. Any abnormal operation is
detected.
(If in doubt about the condition
of the Meter, have it serviced.)
e. Any abnormal operation is
detected.
(If in doubt about the
condition of the Meter, have
it serviced before use.)
f. The battery cover is open.
5. This Meter should be powered only by
3, correctly installed AAA batteries.
6. Use caution when working near
voltages above 30 VAC rms, 42 VAC
peak, or 60 VDC. Voltages this high
present a risk of electric shock.
7. Connect the common (COM) test
lead first and disconnect it last.
8. Hold the probes with fingers
behind guards.
9. Avoid electrical shock. Use extreme
caution when working near uninsulated
conductors or bus bars. Prevent body
contact with grounded surfaces such
as pipes, radiators, ranges, and cabinet
enclosures when testing voltages.
10. Observe work area conditions. Do
not test voltages in damp or wet
locations. Don’t expose to rain.
Keep work area clean and well lit.
11. Keep children away. Children must
never be allowed in the work area.
12. Stay alert. Watch what you are doing,
use common sense. Do not operate
any Meter when you are tired.
13. Do not operate Meter if under the
influence of alcohol or drugs. Read
warning labels on prescriptions to
determine if your judgment or reflexes
are impaired while taking drugs. If there
is any doubt, do not operate the Meter.

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SAFETY OPERATION MAINTENANCESETUP
14. People with pacemakers should
consult their physician(s) before
use. Electromagnetic fields in close
proximity to heart pacemaker could
cause pacemaker interference
or pacemaker failure.
15. Do not test voltage on circuits
higher than 600 volts. This type
of testing should only be done
by a qualified electrician.
16. Do not test current on circuits
higher than 600A.
17. Store idle equipment. When not
in use, Meter must be stored in a
dry location to decrease exposure
to moisture. Lock up Meter and
keep out of reach of children.
18. Dress properly. Protective,
electrically nonconductive
clothes and nonskid footwear are
recommended when working.
19. Wear ANSI-approved safety
goggles during use.
20. Only use accessories intended
for use with this Meter.
21. The warnings, cautions, and
instructions discussed in this
instruction manual cannot cover all
possible conditions and situations
that may occur. It must be understood
by the operator that common sense
and caution are factors which cannot
be built into this product, but must
be supplied by the operator.
22. Avoid damaging Meter. Use only
as specified in this manual.
23. Performance of this Meter may vary
depending on battery condition.
24. Use the proper settings, terminals,
techniques, and range for the
tests performed. Start with the
range stated in the instructions.
25. Do not apply voltage to the Test
Leads when the Meter is in the
Ohms testing setting. Damage
can occur to the Meter.
26. Do not switch between testing modes
with the Meter connected to a circuit.
27. Prior to testing capacitors, resistance,
diodes, or continuity; disconnect all
power to the circuit and discharge
all high-voltage capacitors.
28. Have the Meter calibrated by a
qualified technician every year.
A Meter that is not calibrated yearly
may not yield accurate results.
SAVE THESE INSTRUCTIONS.

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SAFETYOPERATIONMAINTENANCE SETUP
Specifications
DC Voltage Ranges: 200mV / 2V / 20V / 200V / 600V
DC Voltage Accuracy 200mV to 200V 1.5% of rdg + 2d
600V 2% of rdg +2d
TRMS AC Voltage Ranges: 2V/20V/200V/600V
Frequency Range: 50-400Hz
TRMS AC Voltage
Accuracy
2V to 200V 1.5% of rdg + 8d
600V 2.5% of rdg +8d
TRMS AC Current Ranges: 2A / 20A / 200A / 400A
Frequency Range: 50~60Hz
TRMS AC Current
Accuracy
(@2A @400A 3.0% + 8d) ± 2.5% of rdg + 8D
(@20A & 200A) ± 2.5% of rdg + 5D
Resistance Ranges: 200Ω / 2KΩ / 20KΩ / 200KΩ / 2MΩ / 20MΩ
Resistance Accuracy (@200Ω) ± 1.0% of rdg + 4D
(@2kΩ-200kΩ) ± 1.5% of rdg + 4D
(@2MΩ) ± 2.5% of rdg + 4D
(@20MΩ) ± 3.5% of rdg + 4D
Continuity Meter beeps at < 50Ω
Diode Test Forward DC Current: ~ 1mA
Reverse DC Voltage: ~ 2V
Sampling Rate ~3 times/second
Storage Temperature Range: -4°F to 140°F
Operating Temperature Range: 41° - 104° F
Operating Humidity Max 80% RH
Storage Humidity < 80% RH
Operating Altitude 7000ft. (2000meters) maximum
Max Jaw Opening 1.2"
Battery 3x AAA batteries (included)

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SAFETY OPERATION MAINTENANCESETUP
Setup - Before Use:
Read the ENTIRE IMPORTANT SAFETY INFORMATION section
at the beginning of this manual including all text under
subheadings therein before set up or use of this product.
Functions
Current Clamp
Rotary Function
Switch
NCV Test
Clamp Trigger Hold Button
Mode Select / Auto
Backlight Button Max/Min Button
LCD Display
Auto Backlight Sensor
COM Input Jack Positive Input Jack
Battery Cover
(Other Side)

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SAFETYOPERATIONMAINTENANCE SETUP
Display
Symbol Description
AC Alternating Current
DC Direct Current
Minus Sign
Low Battery
Diode Test
Audible Continuity
Auto Power Off
MAX Maximum
MIN Minimum
Data Hold Mode
AUTO Auto Range Mode
2000 Count LCD Display 0 to 1999 measurement Reading
mV, V Volts (Voltage)
µA, mA, A Amps (Current)
Ω, kΩ, MΩ Ohms (Resistance)

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SAFETY OPERATION MAINTENANCESETUP
Operating Instructions
Read the ENTIRE IMPORTANT SAFETY INFORMATION section
at the beginning of this manual including all text under
subheadings therein before set up or use of this product.
Electrical shock can cause death or injury! NEVER TOUCH
exposed conductors of electricity.
General Operating Instructions
MODE/Auto Backlight
Press and hold the
MODE/Auto Backlight button for 2 seconds
to turn the backlight on. Press again for
2 seconds to turn the backlight off.
Note: the Backlight will only illuminate
in dark areas, or if the light sensor
below the LCD screen is covered.
Note: Frequent use of the backlight will
shorten the life of the batteries. Only
use the backlight when necessary.
Data Hold/Backlight
• To freeze the LCD meter reading,
press the Hold/Backlight button.
• While data hold is active, the HOLD
display icon appears on the LCD.
• Press the Hold/Backlight Button
again to return to normal operation.
• Press and hold the Hold/Backlight
Button for 2 seconds to turn the
backlight on, press again for 2
seconds to turn the backlight off.
Note: the Backlight will only illuminate
in dark areas, or if the light sensor
below the LCD screen is covered.
Note: Frequent use of the backlight will
shorten the life of the batteries. Only
use the backlight when necessary.

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SAFETYOPERATIONMAINTENANCE SETUP
MAX/MIN Button
1. Press the MAX/MIN Button to activate
the MAX/MIN/ mode, “MAX” will
appear on the LCD display, the Meter
will display and hold the highest
reading and update the reading
when a higher “Max” occurs.
2. Press the MAX/MIN Button again
to view the lowest reading, “MIN”
will appear on the LCD display, the
Meter will display and hold the lowest
reading and update the reading
when a lower “MIN” occurs.
3. Press and hold the
MAX/MIN Button for 2 seconds
to end MAX/MIN/and return
to normal operation.
Note: MAX/MIN does not
work on Continuity.
Auto Power Off
If Meter is not used for approximately 15 minutes, it will automatically turn
itself off to conserve battery power. To turn Meter back on after auto-off,
press any button or turn the Rotary Function Switch. To disable Auto
Power Off Mode, hold down the MODE button and then power on.
Measurement Operation
Note: Remove plugs from
ends of Test Leads (included)
before connecting to Meter.
Note: Test Lead probes have removable
covers for overvoltage protection. With
covers in place, Test Leads are rated for
use with CAT III circuits. Exposed probes
are rated for use with CAT II circuits.

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SAFETY OPERATION MAINTENANCESETUP
Current Measurement
Measure AC conductors carrying
up to 400 amperes.
WARNING! TO PREVENT SERIOUS
INJURY: To avoid electric shock,
use only one hand to hold Meter
when measuring current.
CAUTION! Remove Test Leads
before taking measurements
with the Current Clamp.
Note: To measure 2- and 3-wire power
cords, use an AC Line Splitter (not included)
and follow its instructions.
1. Turn Rotary Switch to 2A~400A
range. Start with highest range
if amperage is unknown.
2. Using one hand, press Trigger to
open Clamp jaws. Position Clamp
jaws around conductor to be tested.
Guide Guide
3. Center conductor between guides
in Clamp Jaws, as shown.
4. Read measured current on the Display.
Switch to lower ranges, as necessary,
to get the most accurate reading.
5. When testing is complete, turn
Rotary Switch to OFF, and store Meter.
AC Voltage Measurement
Measure AC conductors carrying
up to 600V, 40-400 Hz.
WARNING! TO PREVENT SERIOUS
INJURY: Use caution when working
near voltages above 30 VAC rms, 42
VAC peak, or 60 VDC. Voltages this
high present a risk of electric shock.
1. Plug black test lead into COM Jack.
Plug red test lead into INPUT Jack.
2. Turn Rotary Switch to the
position to choose AC voltage.
3. Carefully touch exposed
conductors with tips of probes.
4. Read measured voltage on the Display.
5. When testing is complete, turn
Rotary Switch to OFF, remove
Test Leads and store with Meter.
Note: If voltage is too high,
Display will read OL.

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SAFETYOPERATIONMAINTENANCE SETUP
DC Voltage Measurement
Measure DC conductors
carrying up to 600 VDC.
WARNING! TO PREVENT SERIOUS
INJURY: Use caution when working
near voltages above 30 VAC rms, 42
VAC peak, or 60 VDC. Voltages this
high present a risk of electric shock.
1. Plug black test lead into COM Jack.
Plug red test lead into INPUT Jack.
2. Turn Rotary Switch to the
position to choose DC voltage.
3. Carefully touch exposed
conductors with tips of probes.
4. Read measured voltage on the Display.
5. When testing is complete, turn
Rotary Switch to OFF, remove
Test Leads and store with Meter.
Note: If voltage is too high,
Display will read OL.
Continuity Measurement
Test continuity between two
points of a circuit.
CAUTION! To prevent electric shock, turn
off all power and fully discharge capacitors
on the circuit under test before measuring.
1. Plug black test lead into COM Jack.
Plug red test lead into INPUT Jack.
2. Turn Rotary Switch to the position.
3. Press MODE until is displayed.
4. Connect the test leads across
the circuit to be measured.
5. Read measured resistance on the
Display. If measured resistance is less
than 50Ω Meter will beep; if the circuit
is open, the display will indicate “OL”.
6. When testing is complete, turn
Rotary Switch to OFF, remove
Test Leads and store with Meter.

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SAFETY OPERATION MAINTENANCESETUP
Diode Measurement
Test voltage drop in diodes.
WARNING! TO PREVENT SERIOUS
INJURY: To prevent electric shock, turn off
all power and fully discharge capacitors on
the circuit under test before measuring.
1. Plug black test lead into COM Jack.
Plug red test lead into INPUT Jack.
2. Turn Rotary Switch to the position.
3. Press MODE until is displayed.
4. Connect red probe to diode’s anode
and black probe to its cathode.
5. Read measured forward biased
voltage drop on the Display.
Note: If the leads are reversed,
OL is displayed.
6. When testing is complete, turn
Rotary Switch to OFF, remove
Test Leads and store with Meter.

Page 13For technical questions, please call 1-888-866-5797.Item 59458
SAFETYOPERATIONMAINTENANCE SETUP
Resistance Measurement
WARNING! TO PREVENT SERIOUS
INJURY: To prevent electric shock, turn off
all power and fully discharge capacitors on
the circuit under test before measuring.
Note: When measuring Ohms,
start with the lowest range if the
resistance is unknown.
1. Plug black test lead into COM Jack.
Plug red test lead into INPUT Jack.
2. Turn Rotary Switch to the position.
3. Press MODE until Ω is displayed.
4. Carefully touch exposed
conductors with tips of probes.
5. Read measured resistance
on the Display.
6. When testing is complete, turn
Rotary Switch to OFF, remove
Test Leads and store with Meter.
Note: Sometimes resistor value and
measured resistance differ. This is due
to the Meter’s output test current going
through all possible paths between leads.
Note: For low resistance measurements,
short the test leads and record the
resistance displayed. Then connect to
the circuit and subtract the recorded
resistance from the measurement
for the most accurate results.
AC NCV (Non-Contact Voltage)
1. Turn Rotary Switch to the position.
2. Move the tip of the clamp close
to the unshielded conductor.
3. If AC voltage is present, the LCD will
display 1 to 3 dashes, Meter will beep
and the Non-Contact Voltage Indicator
will flash. The higher the AC voltage,
the more dashes that will be displayed.
Thicker wire insulation, and different
power outlets will give lower reading.
WARNING! TO PREVENT SERIOUS
INJURY: Even if no indication is given,
voltage may still be present.
Do not rely solely on NCV detection to
determine the presence of voltage.

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SAFETY OPERATION MAINTENANCESETUP
Maintenance and Servicing
Procedures not specifically explained in this manual
must be performed only by a qualified technician.
Cleaning, Maintenance, and Lubrication
1. Wipe unit with a dry, lint-free cloth.
Do not use solvents or abrasives.
2. Remove batteries if not in
use for long periods.
3. Store unit in a dry location.
4. Other than the batteries, there
are no replaceable parts on this
unit. Repairs should be done
by a qualified technician.
Battery Replacement
If the symbol appears on the LCD
display, the battery should be replaced.
1. Remove Test Leads from the Meter.
2. Turn the unit over.
3. Remove screw on battery cover.
4. Remove battery cover carefully.
5. Pull batteries out of unit and
replace with the same.
6. Replace cover and retighten screw.
Calibration
Have the Meter calibrated by a qualified
technician every year to maintain accuracy.

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SAFETYOPERATIONMAINTENANCE SETUP
Record Serial Number Here:
Note: If product has no serial number, record month and year of purchase instead.
Refer to UPC 193175471482

Limited 90 Day Warranty
Harbor Freight Tools Co. makes every effort to assure that its products meet high quality
and durability standards, and warrants to the original purchaser that this product is free from
defects in materials and workmanship for the period of 90 days from the date of purchase.
This warranty does not apply to damage due directly or indirectly, to misuse, abuse, negligence
or accidents, repairs or alterations outside our facilities, criminal activity, improper installation,
normal wear and tear, or to lack of maintenance. We shall in no event be liable for death,
injuries to persons or property, or for incidental, contingent, special or consequential damages
arising from the use of our product. Some states do not allow the exclusion or limitation of
incidental or consequential damages, so the above limitation of exclusion may not apply to you.
THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR
IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS.
To take advantage of this warranty, the product or part must be returned to us with transportation
charges prepaid. Proof of purchase date and an explanation of the complaint must accompany
the merchandise. If our inspection verifies the defect, we will either repair or replace
the product at our election or we may elect to refund the purchase price if we cannot readily
and quickly provide you with a replacement. We will return repaired products at our expense,
but if we determine there is no defect, or that the defect resulted from causes not within
the scope of our warranty, then you must bear the cost of returning the product.
This warranty gives you specific legal rights and you may also
have other rights which vary from state to state.
26677 Agoura Road • Calabasas, CA 91302 • 1-888-866-5797