Centech 90939 User manual

8 FUNCTION DIGIT8 FUNCTION DIGIT
8 FUNCTION DIGIT8 FUNCTION DIGIT
8 FUNCTION DIGITAL MULAL MUL
AL MULAL MUL
AL MULTIMETERTIMETER
TIMETERTIMETER
TIMETER
OPERATING INSTRUCTIONS
3491 Mission Oaks Blvd., Camarillo, CA 93011
Visit ourWeb site at http://www.harborfreight.com
Copyright©2004byHarborFreightTools®. Allrightsreserved.Noportion
of this manual or any artwork contained herein may be reproduced in any
shape or form without the express written consent of Harbor FreightTools.
For technical questions and replacement parts, please call 1-800-444-3353
®
90939

SKU90939 Page2
Specifications
SaveThisManual
You will need the manual for the safety warnings and
precautions, and operating and maintenance procedures.
Keep your invoice with this manual. Write the invoice number
on the inside of the front cover. Keep the manual and invoice
in a safe and dry place for future reference.
Safety Warnings and Precautions
WARNING: When using tool, basic safety precautions should always be
followed to reduce the risk of personal injury and damage to
equipment.
Read all instructions before using this tester!
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SKU90939 Page3
1. Test cable voltages with care. Only use one hand when securing
the tester around the cable to reduce risk of injury in case of electric
shock.
2. Avoid working alone. If an accident happens, an assistant can
bringhelp.
3. Keep work area clean. Cluttered areas invite injuries.
4. Avoid electrical shock.Useextremecautionwhen clampingaround
uninsulated conductors or bus bars. Prevent body contact with
grounded surfaces such as pipes, radiators, ranges, and cabinet
enclosures when testing voltages.
5. Avoid damaging meter.Use only as specified in this manual.
6. Observe work area conditions. Do not test voltages in damp or
wet locations. Don’t expose to rain. Keep work area well lit.
7. Keep children away. Children must never be allowed in the work
area. Do not let them handle machines, tools, or extension cords.
8. Store idle equipment. When not in use, tools must be stored in a
dry location to inhibit rust. Always lock up tools and keep out of
reach of children.
9. Dress properly. Do not wear loose clothing or jewelry as they can
be caught in moving parts. Protective, electrically nonconductive
clothesandnonskid footweararerecommendedwhen working.Wear
restrictive hair covering to contain long hair.
10. Use eye protection. Always wear ANSI approved impact safety
goggles.
11. Do not overreach. Keep proper footing and balance at all times.Do
not reach over or across electrical cables or frames.
12. Maintain tools with care. Ensure multimeter has a fresh battery.
Inspect tool cords periodically and, if damaged, have them repaired
by an authorized technician.
13. Stay alert. Watch what you are doing, use common sense. Do not
operate any tool when you are tired.
14. Check for damaged parts. Before using any tool, any part that
appears damaged should be carefully checked to determine that it
will operate properly and perform its intended function. Check for
alignmentand bindingof moving parts;anybrokenpartsor mounting
fixtures; and any other condition that may affect proper operation.
Any part that is damaged should be properly repaired or replaced by

SKU90939 Page4
Unpacking
When unpacking, make sure the following parts are included:Digital Clamp
Multimeter, black and redTest Leads, hand strap, and carrying case.If any parts are
missingor broken, pleasecall HarborFreightToolsat thenumberonthe coverof this
manual. If any part of the machine is missing or broken, please call Harbor Freight
Tools at the number on the front cover as soon as possible.
aqualifiedtechnician.Donotusethetoolifanyswitchdoesnotoperate
properly.
15. Replacement parts and accessories. When servicing, use only
identical replacement parts. Use of any other parts will void the
warranty. Only use accessories intended for use with this tool.
Approved accessories are available from Harbor Freight Tools.
16. Do not operate tool 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 tool.
17. We recommend that only a licensed electrician work on high-
voltage or other potentially dangerous circuits.
Note: Performance of this tool may vary depending on condition of internal
battery.
Warning: The warnings, cautions, and instructions discussed
in this instruction manual cannot cover all possible
conditions and situations that may occur. It must be
understoodby the operatorthat common sense and
caution are factors which cannot be built into this
product, but must be supplied by the operator.
Warning: This product contains or produces chemicals,
including lead, known to the State of California to
cause cancer and birth defects (or other
reproductive harm).
(California Health & Safety Code 25249.5 et seq.)
Operation
WARNING:ELECTRICAL SHOCK CAN CAUSE DEATH OR
INJURY. AVOID TOUCHING EXPOSED CONDUCTORS
OF ELECTRICITY.
Additional Multimeter Precautions
1. Do not test voltage on circuits higher than 600 volts.

SKU90939 Page5
2. Donottestcurrent on circuits
higher than 10 AMPs.
3. Be careful not to apply
voltage to the Test Leads
when they are connected to
the COM (Center)
and Ohm (Left)
Jacks and the
Multimeter is in an
Ohms testing
setting. Damage
can occur to the
multimeter or the
fuse may blow.
4. Donotswitchbetweentesting
modes with the multimeter
connected to a circuit.
AC Voltage Measurements
Measure AC conductors carrying up to 600VAC, 40-500 Hz.
1. Turn the Range Selector Switch to 600V~ setting.
Always start with the highest range if the voltage is unknown.
2. Plug the red lead into theVolt (Left) Jack.Plug the black lead into the COM
(Center)Jack.
3. Carefullytouchtheexposedconductorswith thetipsoftheprobestomeasure
thevoltage (notamperes).
4. Readmeasurement.
If the voltage is less than 200 volts, set the Range Selector Switch to the
lowerrange.
5. Optionally, press the Data Hold button to keep the display reading the same
afterthe leads havebeen removed fromthe conductors. Press andrelease
theData Holdbutton again toresume normaloperation.
6. When testing is complete, removeTest Leads and store with multimeter.
DC Voltage Measurements
MeasureDC conductors carryingup to 600VDC.
1. Turn the Range Selector Switch to 600V setting.
2. Followthe directionsaboveunder“ACVoltage Measurements”,onlyuse the
DC settings instead.
10A JackCOM Jack
Volt/Ohm/
mA Jack
DC AMP
Selection
Area
DC Volt
Selection
Area
AC Volt
Selection
Area
Ohm
Selection
Area
LED/
Transistor
Selection
Area
OFF
Selection
Control Layout
Data Hold
Button
...
_

SKU90939 Page6
DC Current Measurements
MeasureDC conductors carryingup to10 amperes.
1. Turn the Range Selector Switch to the position.
Always start with the highest range if the amperage is unknown.
2. Plugthe redlead intothe 10A(Right) Jack.Plug theblack leadinto theCOM
(Center)Jack.
3. Carefullytouchtheexposedconductorswith thetipsoftheprobestomeasure
theamperage.
4. Readmeasurement.
If the reading is less than .2 AMPs,switch the red lead to the Left AMP Jack
and set the Range Selector Switch to the 200 mA setting.
5. Optionally, press the Data Hold button to keep the display reading the same
afterthe leads havebeen removed fromthe conductors. Press andrelease
theData Holdbutton again toresume normaloperation.
6. When testing is complete, removeTest Leads and store with multimeter.
Resistance Measurements
Measure circuit resistance up to 20M Ohms.
WARNING:NEVER measureresistance on acircuit with voltagerunning throughit.
1. Turn the Range Selector Switch to the 200 Ωposition.
2. Plug the red Test Lead into the Ohms (Left) Jack. Plug the black Test Lead
into the Com (Center) Jack.
Short theTest Leadstogether.Themeter should read“0”Ohms.
3. Touch the exposed conductors with the tips of theTest Leads.
4. Read measurement.
Ifthe readingis 1, setthe RangeSelector Switchto the nexthigher Ohm(Ω)
position.
5. Optionally, press the Data Hold button to keep the display reading the same
afterthe leads havebeen removed fromthe conductors. Press andrelease
theData Holdbutton again toresume normaloperation.
Transistor(hFE)/LED Measurements
Test transistors and LEDs to ensure proper function.
1. Turn the Range Selector Switch to the NPN or PNP position depending on
what type of transistor is to be tested. To test a LED use the NPN position.
ForTransistors:
a. Insert the transistor pins into the hFE jack according to the EBC (Emitter,
Base,Collector) sequence.
b. The meter will show the approximate hFE value.
...
_
10A
20

SKU90939 Page7
NOTE: No replacement parts are available for this tool.
Battery/FuseReplacement
To replace the battery or fuse:
1. Remove theTest Leads from the multimeter.
2. Turntheunit over.
3. Remove the screw using a Philips screwdriver.
4. Remove back cover.
5. Pull battery/fuse out of unit and replace with the same.
(9V battery or .5A/250V fast-acting fuse)
6. Replacecoverand retighten screw.
MeasurementApplications
• Household uses – Verify and measure current flow and voltage to such
appliances as electric water heaters, fan motors, generators, and pumps.
Measure excessive current flow on circuits in distribution panels which are
tripping circuit breakers. Check for wire continuity or resistance using the
Test Leadsand Ohms function.
• Distribution transformers – Measure load on each phase for balance and
forexcessivecurrent.
• Motors – Measure starting current, running current, and current imbalance
betweenphases.
• Variable speed motor controllers –Measure inputand output currents.
Maintenance
1. Wipeunitwithaslightlydampclothusingalightdetergent.Donotusesolvents
orabrasives.
2. Remove battery if not in use for long periods.
3. Store unit in a dry location.
4. Other than the battery and fuse, there are no replaceable parts on this unit.
Repairsshould be done byaqualified technician.
For LEDs:
a. Insert the LED’s pins into the + and - signs into the hFE jack.
b. A working LED should shine brightly. The meter reading is unimportant.
c. This function is only used to test an LED rated at 1.5~3V in regards to
brightness.