AUTO RANGING CAT III 600V DIGITAL MULTIMETER USER S MANUAL DMM45

Transcription

1 AUTO RANGING CAT III 600V DIGITAL MULTIMETER USER S MANUAL DMM45 Please read this manual carefully and thoroughly before using this product.

2 TABLE OF CONTENTS Introduction Key Features What's in the Blister Pack Product Overview Safety Instructions Setup Instructions Install Batteries Operating Instructions General Instructions Using Auto Ranging Turning On the Backlight Auto Power Off Measuring AC or DC Voltage Measuring AC or DC Current Measuring Resistance Measuring Temperature Checking for Continuity Checking the Integrity of a Diode Specifications Operating & Maintenance Tips Replacing the Fuse Warranty Information Return for Repair Policy

3 INTRODUCTION Thank you for purchasing General Tools & Instruments (General s) DMM45 Auto Ranging CAT III 600V Digital Multimeter. Please read this user s manual carefully and thoroughly before using the instrument. The DMM45 is designed for use in an industrial setting by HVAC/R contractors, building maintenance technicians, MRO (maintenance, repair and operations) personnel at process and power plants, electricians, and electrical/electronic technicians. The meter is affordable, reliable, easy to use, ruggedly built and designed to meet the CAT III 600V safety standard. KEY FEATURES 8 functions, 25 ranges Measures 1) AC voltage over five ranges, 2) DC voltage over five ranges, 3) DC current over four ranges, 4) AC current over four ranges, 5) resistance over six ranges, and 6) temperature over one range using included K type stem thermocouple probe Uses beeper to 7) verify integrity of diodes and 8) check circuits for continuity Large backlit 3-1/2 digit (2,000 count) LCD LIGHT (backlight) button 15 minute Auto Power Off (APO) Designed to meet CAT III 600V safety standard 1 year limited warranty 3

4 WHAT S IN THE BLISTER PACK The meter is supplied in a blister pack with a cavity in the rear. Inside the cavity are a pair of double-insulated 20AWG test leads, a K type stem thermocouple probe, and two AAA batteries. This user s manual is supplied inside the fold-over blister card. PRODUCT OVERVIEW Fig. 1 shows the labels and positions of the controls, indicators and physical structures of the DMM45. Fig. 2 shows all possible indications on the meter s LCD. Familiarize yourself with the functions and meanings of these controls, indicators and connectors before moving on to the Setup Instructions and Operating Instructions. Fig. 1. The controls, indicators and physical structures of the DMM LCD 4 2. LIGHT button. Pressed and held for >3 seconds, turns on display backlight for 15 seconds. Pressed and held 5 with backlight on, turns } backlight off. 3. SHIFT button. Used to toggle between 1) AC and DC current measurement modes, 2) continuity and diode integrity check modes, and 3) F or C display of temperature 4. Rotary function switch 5. Jacks for test leads 4 1 3

5 Fig. 2. All possible display indications SAFETY INSTRUCTIONS WARNING To avoid possible electric shock or personal injury, and to avoid damaging the meter or the equipment under test: Do not use the meter in any way not detailed in this manual or the meter's safety features may be compromised. Before using the meter, inspect the case. Do not use the meter if it is damaged. Look for cracks or missing plastic. Pay particular attention to the area near the test lead jacks. WARNING Inspect the test leads for damaged insulation or exposed metal. Check the test leads for continuity. Replace damaged leads before using the meter. Verify the meter s operation by measuring a known voltage. Do not use the meter if it operates abnormally. Protection may be impaired. When in doubt, have the meter checked and serviced by a qualified technician. WARNING Do not apply more than the rated voltage, as marked on the front of the meter, between the terminals or between either terminal and ground. 5

6 WARNING Do not measure current above 600V in Category III installations. WARNING Do not measure voltage with the rotary function switch in any resistance (ohms) or current position. Doo not measure current with the rotary function switch in any resistance position. Use caution when working with voltages above 42VAC RMS, or 60VDC. These voltages pose a shock hazard. Use the proper terminals, function, and range for all measurements. WARNING Do not operate the meter around explosive gas, vapor, or dust. WARNING When using the test leads, keep your fingers behind the finger guards. Do not touch the metal probes of the test leads when making a measurement. When making connections, connect the black ( ) test lead before connecting the red (+) test lead; when disconnecting, disconnect the red (+) test lead before disconnecting the black ( ) test lead. Disconnect circuit power and discharge all high-voltage capacitors before measuring/testing for resistance, continuity or diodes. Before making DC voltage measurements, verify that AC voltages are not present by making measurements in AC voltage mode. Then select a DC voltage range equal to or greater than the AC range. Before measuring current, turn off power to the circuit before connecting the meter. Do not operate the meter with the case (or part of the case) removed. 6

7 Use only two AAA batteries, properly installed in the battery compartment, to power the meter. Do not use rechargeable batteries. Replace the batteries as soon as the low battery indicator appears on the LCD. Operated with weak batteries, the meter might produce false readings that could lead to electric shock and personal injury. Remove the test leads from the meter before opening the meter meter s or battery compartment. Electrical Symbols Used On the Meter and In This Manual Symbol Description Symbol Description AC (Alternating Fuse Current) DC Double (Direct Current) Insulated Caution, risk of Risk of danger. electric shock. Important Hazardous information. voltage. Refer to the manual. Battery (Low battery) Earth ground when shown on display Diode Continuity Beeper AC or DC Complies with EU directives 7

8 Symbol Description Symbol Description Application and removal from hazardous live conductors permitted SETUP INSTRUCTIONS INSTALL BATTERIES For measurements made on building equipment such as distribution panels, feeders and short branch circuits, and on lighting systems in large buildings. The DMM45 s battery compartment is located at the bottom rear of the meter. To open the compartment, use a small Phillips-head screwdriver to remove the three silver screws securing the battery compartment cover. Put the screws and the cover to the side and take care not to lose the small screws. Remove the two AAA batteries from the rear cavity of the blister pack. Install them in the battery compartment, taking care to observe the polarity markings inside the compartment. Replace the battery compartment cover and secure it with the three Phillips-head screws. 8

9 OPERATING INSTRUCTIONS GENERAL INSTRUCTIONS Using Auto Ranging. The DMM45 is an auto ranging multimeter that cannot be operated in manual ranging mode. The meter automatically chooses the full-scale measurement range that maximizes measurement resolution for all measured parameters (except temperature, for which there is only one full-scale range). The Specifications section on pages 14 & 15 lists the full-scale ranges (and their resolutions) available for measuring DC volts, AC volts, AC amps, DC amps and resistance (in ohms). Turning On the Backlight Pressing and holding the LIGHT button (Fig. 1, Callout 2) for at least 3 seconds turns on the LCD s bright white backlight, making measurements much easier to read in dark spaces. To extend battery life, the backlight is automatically turned off after 15 seconds. Auto Power Off The DMM45 is equipped with an Auto Power Off (APO) circuit that automatically powers off the meter if no front-panel button is pressed within any span of 15 minutes. The purpose of the APO feature is to extend battery life. The meter announces that APO shutdown is imminent by producing five short beeps after 14 minutes of inactivity. To keep the meter from shutting down, immediately press the LIGHT button or change the position of the rotary function switch. After 15 minutes of inactivity, the APO function will shut down the meter and announce the action with a long beep. 9

10 MEASURING AC OR DC VOLTAGE WARNING Do not measure any voltage higher than 500V. Doing so may blow the meter s internal fuse and/or damage the meter s internal circuitry. (1) Set the rotary function switch to the (DC voltage) or (AC voltage) position. If you choose the position, DC will appear on the left side of the LCD (see Fig. 2). If you choose the position, AC will appear on the left side of the LCD. (2) Plug the red test lead into the V/Ω/mA jack on the front of the meter and the black test lead into the COM jack. (3) Touch the black test lead to the lower-potential point of the circuit under test, and the red test lead to the higherpotential point. (4) Read the measured voltage amplitude on the LCD. If the test leads are reversed, a minus sign will appear at the left of the displayed value. MEASURING AC OR DC CURRENT WARNING Before inserting test leads into a circuit, remove power from the circuit. (1) Set the rotary function switch to the position. (2) Using the SHIFT button, select DC or AC current measurement mode (indicated by the presence of DC or AC on the left side of the LCD). (3) Plug the red test lead into the V/Ω/mA jack on the front of the meter and the black test lead into the COM jack. 10

11 (4) Connect the test leads in series with the device whose current flow you wish to measure. (5) Read the measured current amplitude on the LCD. If the test leads are reversed, a minus sign will appear at the left of the displayed value. If the amplitude of the current you are measuring is greater than 200mA, OL (for overload) will appear on the LCD. If your readings are consistently less than 0.2mA, turn the rotary function switch to the position to improve your measurement resolution. MEASURING RESISTANCE WARNING To avoid electrical shock or damage to the meter when measuring resistance or continuity in a circuit, make sure the power to the circuit is turned off and all capacitors are discharged. (1) Turn the rotary function switch to the Ω position. (2) Plug the red test lead into the V/Ω/mA jack on the front of the meter and the black test lead into the COM jack. (3) Measure the resistance by touching the tips of the leads across the resistor or between the desired test points of the circuit, as shown below. RED TEST LEAD BLACK TEST LEAD (4) Read the measured resistance on the LCD. If the measured resistance is greater than 20MΩ, O.L will appear on the LCD to indicate an overload. 11

12 MEASURING TEMPERATURE (1) Turn the rotary function switch to the F or C position. (2) Plug the two-prong connector of the supplied K type thermocouple probe into the jacks on the front of the meter. Make sure to plug the prong labeled + into the V/Ω/mA jack and the prong labeled - into the COM jack. (3) Read the temperature on the LCD. To quickly switch from F to C or vice-versa, press the SHIFT button. CHECKING FOR CONTINUITY (1) Turn the rotary function switch to the position. An icon of a diode will appear at the lower left of the LCD. (2) Press the SHIFT button. The icon of a diode will change to the continuity icon ( ). Until the test leads are plugged into the meter s front-panel jacks, OL. will appear on the LCD to indicate an open circuit. (3) Plug the red test lead into the V/Ω/mA jack on the front of the meter and the black test lead into the COM jack. (4) Touch the test leads to any two points of a circuit. If the resistance between those points is <30Ω, the beeper will sound continuously. If there is no continuity (an open circuit or a resistance greater than 30Ω between the two points), OL. will appear on the LCD. 12

13 CHECKING THE INTEGRITY OF A DIODE (1) Turn the function switch to the position. An icon of a diode will appear at the lower left of the LCD. Until the test leads are plugged into the meter s front-panel jacks,.ol will appear on the LCD to indicate an open circuit. (2) Plug the red test lead into the V/Ω/mA jack on the front of the meter and the black test lead into the COM jack. (3) Connect the red test lead to the anode (positive terminal) of the diode to be tested, and the black test lead to its cathode (negative terminal). RED TEST LEAD BLACK TEST LEAD (4) Read the forward bias voltage value on the LCD. A silicon diode typically has a forward bias voltage of 0.7V. A germanium diode typically has a forward bias voltage of 0.3V. A 0V reading in both directions indicates a shorted diode. A reading of 1 indicates an open diode. In either case, the diode is defective and should be replaced. 13

14 SPECIFICATIONS Parameter or Feature/Function Specification Value AC voltage Measurement 0 to 200mV/2V/20V/200V/500V ranges Measurement 0.1mV/1mV/10mV/100mV/1V resolutions Measurement ±(0.8% of reading + 5 digits) accuracy DC voltage Measurement 0 to 200mV/2V/20V/200V/500V ranges Measurement 0.1mV/1mV/10mV/100mV/1V resolutions Measurement ±(0.5% of reading + 5 digits) accuracy AC current Measurement 0 to 200μA/2mA/20mA/200mA ranges Measurement 0.1μA/1μA/10μA/100μA resolutions Measurement ±(1.8% of reading + 3 digits) accuracy DC current Measurement 0 to 200μA/2mA/20mA/200mA ranges Measurement 0.1μA/1μA/10μA/100μA resolutions Measurement ±(1.8% of reading + 2 digits) accuracy Resistance Measurement 0 to 200Ω/2kΩ/20kΩ/200kΩ/2MΩ/20MΩ ranges Measurement 0.1Ω/1Ω/10Ω/100Ω/1kΩ/10kΩ resolutions Measurement ±(1.5% of reading + 2 digits) accuracy 14

15 Parameter or Feature/Function Specification Value Temperature Measurement -40 to 752 F (-40 to 400 C) range Measurement 1 (F or C) resolution Measurement accuracy ±(8% of reading + 8 digits) below 32 F (0 C); ±(1.2% of reading + 7 digits) from 32 to 212 F (0 to 100 C); ±(3% of reading + 3 digits) from 212 to 752 F (100 to 400 C) Continuity threshold <30Ω Overload protection level 600VAC/DC Input impedance 10MΩ Frequency response 50/60Hz Ingress protection (IP) rating IP20 Safety rating CAT III 600V Test leads Double-insulated, 20 AWG, 1A max rating Display No. of digits 3-1/2 Maximum count 2000 Size 2.4 x 1 in. (62 x 26mm) Digit height 0.63 in. (16mm) Auto Power Off trigger 15 minutes of front-panel inactivity Backlight duration 15 seconds Operating temperature 32 to 122 F (0 to 50 C)@<75%RH Operating altitude (max) 6562 ft. (2000m) Dimensions 8.86 x 3.31 x 1.30 in. (225 x 84 x 33mm) Weight (including batteries) 6.3 oz. (179g) Power source (2) AAA batteries (IEC LR03) Battery life 200 hours (typical) Note: Accuracy values stated for operation at 23 ±3 15

16 OPERATING & MAINTENANCE TIPS When the icon appears at the upper right of the LCD (see Fig. 2), it s time to replace the two AAA batteries that power the meter (although measurements will remain valid for several hours after the icon first appears). To replace the batteries, follow the instructions on p. 8. Do not operate the DMM45 in the presence of a flammable or explosive gas or near an arc welder or induction heater. After subjecting the meter to a large change in ambient temperature, wait at least 30 minutes before making measurements to guarantee the accuracy of readings. Remove the batteries when storing the meter or when you do not expect to use it for an extended period of time (months rather than weeks). Do not disassemble the DMM45 or immerse it in water. REPLACING THE FUSE The DMM45 is equipped with a 200mA/250V cylindrical fuse in series with the V/Ω/mA jack. The fuse is located in the battery compartment, above the two AAA batteries (see photo below). 16

17 To replace the fuse, open the battery compartment by removing the three screws securing its cover. Be careful not to shatter the glass of the blown fuse when removing it, and take care not to lose the small screws after opening the compartment. WARRANTY INFORMATION General Tools & Instruments (General s) DMM45 Auto Ranging CAT III 600V Digital Multimeter is warranted to the original purchaser to be free from defects in material and workmanship for a period of one year. Subject to certain restrictions, General will repair or replace this instrument if, after examination, the company determines it to be defective in material or workmanship. The warranty period begins on the date of purchase. You are encouraged to register your product online. General will extend your warranty an additional 60 days if you register at This warranty does not apply to damages that General determines to be from an attempted repair by non-authorized personnel or misuse, alterations, normal wear and tear, or accidental damage. The defective unit must be returned to General Tools & Instruments or to a General-authorized service center, freight prepaid and insured. Acceptance of the exclusive repair and replacement remedies described herein is a condition of the contract for purchase of this product. In no event shall General be liable for any incidental, special, consequential or punitive damages, or for any cost, attorneys fees, expenses, or losses alleged to be a consequence of damage due to failure of, or defect in any product including, but not limited to, any claims for loss of profits. 17

18 Register now at to receive a 60-day extension to your warranty. RETURN FOR REPAIR POLICY Every effort has been made to provide you with a reliable product of superior quality. However, in the event your instrument requires repair, please contact our Customer Service to obtain an RGA (Return Goods Authorization) number before forwarding the unit via prepaid freight to the attention of our Service Center at this address: General Tools & Instruments 80 White Street New York, NY Remember to include a copy of your proof of purchase, your return address, and your phone number and/or address. 18

19 NOTES 19

20 GENERAL TOOLS & INSTRUMENTS 80 White Street New York, NY PHONE (212) FAX (212) TOLL FREE (800) DMM45 User s Manual Specifications subject to change without notice 2013 GENERAL TOOLS & INSTRUMENTS NOTICE - WE ARE NOT RESPONSIBLE FOR TYPOGRAPHICAL ERRORS. MAN# DMM45 10/03/13