Instruction Manual - Davis Instruments
Contents
1. If the mains switch is opened and the motor also has a motor starter then the starter must be held in the ON position With the mains switch opened the measured resistance will include the resistance of the motor wire and all other components between the motor and the main switch If a weakness is indicated the motor and other components should be checked individually If the motor is disconnected at the motor terminals connect one meter lead to the grounded motor housing and the other lead to one of the motor leads Refer to diagram at below Line The STARTER must be in the ON position during the test 2 The motor to meter connection must be made to the motor housing ground 3 The meter to main switch connection must be to the motor side of the main switch as shown 8 Model 380363 Version 2 0 J uly 2005 Testing DC Motors i 2 Disconnect the motor from the line To test the brush rigging field coils and armature connect one meter lead to the grounded motor housing and the other lead to the brush on the commutator If the resistance measurement indicates a weakness raise the brushes off of the commutator and separately test the armature field coils and brush rigging one at a time Leave one lead connected to the grounded motor housing while testing the motor components This also applies to DC Generators Testing Cables 1 2 Disconnect the cable under test from the line Discon2. Test ranges Resistance 4MQ 40M9 400M9 4000MQ 10GQ Test Voltages 250V 500V 1000V AC DC Voltage range 999V Resistance range 99990 Lo Resistance range 400 Over range indicator OL displayed when measurement exceeds range Zero adjust Automatic Memory Nine 9 data records Low battery indicator BT symbol displayed when battery voltage is low Power source Six 6 1 5 AA batteries Power consumption 20 to 95mA depending upon function Fuse protection 0 5A 600V fast blow fuse Operating conditions 32 to 122 F 0 to 50 C 80 RH Dimensions 9 3 x 4 6 x 2 1 235 x 116 x 54mm Weight 1 15 Ibs 520g Safety ratings Pollution degree 2 indoor use CE marked Meets IEC 61010 1 and IEC 61557 standards Category Rating CAT III 1000V 2 Model 380363 Version 2 0 J uly 2005 Range Specifications MEGOHMMETER RANGES Range Test Voltages Resolution Accuracy amo eens 3 5 lt 1000M 40MQ 250V 30 0 0 01MQ 500V 30 0 5 t 5 gt 1000M 400MO 1000V 30 0 oMa 4000MQ 1MQ reading digits at 23 C 5 C lt 80 RH 10GQ 00 01GQ Analog Bar Graph 0 to 10GO Nominal Current 2 1mA Circuit Protection Test inhibited if input 2 30V AC or DC AC VOLTAGE 40Hz 500Hz Range Res A
3. instrument to be free of defects in parts and workmanship for one year from date of shipment a six month limited warranty applies on sensors and cables If it should become necessary to return the instrument for service during or beyond the warranty period contact the Customer Service Department at 781 890 7440 ext 210 for authorization or visit our website at www extech com click on Contact Extech and go to Service Department to request an RA number A Return Authorization RA number must be issued before any product is returned to Extech The sender is responsible for shipping charges freight insurance and proper packaging to prevent damage in transit This warranty does not apply to defects resulting from action of the user such as misuse improper wiring operation outside of specification improper maintenance or repair or unauthorized modification Extech specifically disclaims any implied warranties or merchantability or fitness for a specific purpose and will not be liable for any direct indirect incidental or consequential damages Extech s total liability is limited to repair or replacement of the product The warranty set forth above is inclusive and no other warranty whether written or oral is expressed or implied Copyright 2005 Extech Instruments Corporation All rights reserved including the right of reproduction in whole or in part in any form 10 Model 380363 Version 2 0 J uly 2005
4. User Guide EXTECH INSTRUMENTS Model 380363 Insulation Tester Megohmmeter EXTECH 330363 wo f0i2 HOLD O OH 0 o Mo 250v OFF Loo Auto Discharge Introduction Congratulations on your purchase of Extech s Insulation Tester Megohmmeter The Model 380363 provides three test ranges plus continuity and AC DC voltage measurement Manual datalogging stores up to 9 data sets This professional meter with proper care will provide years of reliable service Safety 1 Circuits under test must be de energized and isolated before connections are made except for voltage measurements 2 Circuit connections must not be touched during a test Use extreme caution when working near bare conductors and bus bars Accidental contact with conductors could result in electrical shock 3 Use caution when working near voltages above 60VDC or 30VACrms After insulation tests capacitors must be discharged 5 Test leads including alligator clips must be in good working order clean and without broken or cracked insulation 6 When servicing use only specified replacement parts International Safety Symbols A Caution refer to this manual before using this meter AN Dangerous Voltages O Meter is protected throughout by double or reinforced insulation Specifications General specifications Display 3 3 4 digit 4000 count LCD Sampling rate 1 reading per second
5. ccuracy Input impedance Overload Protection 999VAC 1V 2 2d 9MQ 1000Vrms DC VOLTAGE Range Res Accuracy Input impedance Overload Protection 999VDC 1V 1 2d 9MQ 1000Vrms RESISTANCE amp CONTINUITY Range Res Accuracy Max open circuit Overload Volt Protect Resistance 999 90 0 10 1 3d 3V 1000Vrms Continuity 1009 809 LOW RESISTANCE Q Range Res Accuracy Max open Overload circuit Volt Protection 409 0 010 2 2d 6V gt 30V AC DC 3 Model 380363 Version 2 0 J uly 2005 Meter Description The tilt stand and battery compartment are located at the rear of the instrument LCD Display LOCK button MEMORY control button UP arrow key TEST button Rotary switch DOWN arrow key READ memory button ZERO adjust button 0O 0 Ot O EG IS 10 Input terminals Waming Ensure that the circuit under test does not include components that can be damaged by 1000VDC such devices include power factor correction capacitors low voltage mineral insulated cables electronic light dimmers and ballasts starters for fluorescent lamps Operation Co nnecting Test Leads For all measurements connect the red test lead to the VQ input terminal and the black test lead to the COM input terminal Test Lead Check 1 2 3 4 5 Set the rotary switch to the Q 773 range Touch the test lead tips together Resistance should read less than 0 5Q and the audio tone should sound With the leads
6. display shows 0 volts Test Lock Function For hands free operation use the TEST LOCK feature 1 With the test leads connected to the equipment under test press the LOCK key to enter the LOCK mode The LOCK icon a will appear on the display 2 Press the TEST key to start the test A beeper will sound every 2 seconds to indicate that the meter is in Lock mode 3 Press LOCK or TEST to disable the Lock function and end the test Notes on IR Megohmeter testing 1 The maximum measurement range for the 380363 is 10GQ Frequently insulation resistance will exceed this value and the meter will show the overload display symbol OL indicating that the insulation under test is good 2 If the device being tested is highly capacitive the display will indicate an increasing resistance value over time Allow the reading to stabilize before ending a test Manual Data Store and Read Mode To Clear Memory 1 Turn the meter off 2 Press and hold down the MEM key and turn the meter on 3 The display will show MEMO in the upper left hand corner indicating that the memory has been erased Entering data into memory 1 Press the MEM key to enter the displayed data into memory a beep will sound 2 The display will show MEM and the memory address number in the upper left hand corner Total memory size is 9 sets 3 When memory is full the meter will sound two quick beeps Reading memory data 1 Press the READ key to ent
7. ep and the flashing high voltage symbol f will be displayed if the voltage is over 30V Remove the voltage before proceeding to the next step Press and hold the TEST key until a stable reading is displayed Release the TEST key The upper right hand display will hold the reading until a new test is started or a different function is selected Swap the red and black probes to reverse the polarity of the test current The reading should remain the same This test is useful to detect corroded connections which can cause different readings in both polarities 6 Model 380363 Version 2 0 J uly 2005 Using the LOCK Function to measure resistance The Lock function can be used to make several resistance measurements in succession without the need to push and hold the TEST key for each measurement 1 Press the LOCK key to enter the LOCK mode and then press the TEST key 2 Zero out the test lead resistance 3 Connect the probes to the test locations in succession 4 Press the LOCK key to disable the lock function Note The meter cannot indicate if the circuit is live in this mode Ensure that the circuit is de energized before connecting the test leads or the fuse may blow Auto Power Off To conserve battery life the meter will automatically turn off after 15 minutes of non use To turn the meter back on turn the rotary switch to OFF then to the desired function Analog Bar Graph The analog bar graph displays resistance on a l
8. er Read Mode The display will show the READ icon and the memory address number in the upper left hand corner 2 Usethe a and arrow keys to scroll through the stored readings 3 Press the READ key again to exit this mode 5 Model 380363 Version 2 0 J uly 2005 AC DC Voltage Measurement Set the Rotary switch to the V position Connect the red test lead to the VQ terminal and the black test lead to the COM terminal Connect the test leads to the circuit under test Read the voltage value on the LCD The meter shows DC voltage in the upper right and AC voltage on the main display Resistance Measurement and Audible Continuity Test WARNING Do not run this test unless ACV 0 Do not use this mode to check diodes POON o gt Set the Rotary switch to the Q position Connect the red test lead to the VQ terminal and the black lead to the COM terminal Connect the tips of the test leads to the circuit under test Read the resistance value on the display When the resistance of a circuit is less than approx 100Q 80Q the audible tone will sound LOQ Low Resistance Measurement 1 2 Set the Rotary switch to the LoQ position Connect the red test lead to the VQ terminal and the black lead to the COM terminal a Touch the test leads together and press the Zero key to zero the display Connect the probes to the ciruit under test If there is a voltage present it will be displayed A repetitive be
9. nect the opposite end of the cable to avoid errors as a result of leakage from other equipment Check each conductor to ground and or lead sheath by connecting one meter lead to ground and or lead sheath and the other meter lead to each of the conductors in turn Check insulation resistance between conductors by connecting meter leads to conductors in pairs Refer to diagram In the diagram note that the 3 conductor cable has two wires shorted to the ground shield This two wire shield connection is then connected to one side of the meter The remaining conductor is connected to the other side of the meter ma sw OFF lon 9 Model 380363 Version 2 0 J uly 2005 Repair and Calibration Extech offers repair and calibration services for the products we sell Extech also provides NIST certification for most products Call the Customer Service Department for information on calibration services available for this product Extech recommends that annual calibrations be performed to verify meter performance and accuracy T Support line 781 890 7440 Technical support Extension 200 E mail support extech com Repair amp Returns Extension 210 E mail repair extech com Product specifications subject to change without notice For the latest version of this User s Guide Software updates and other up to the minute product information visit our website www extech com Warranty EXTECH INSTRUMENTS CORPORATION warrants this
10. not touching the display should read OL indicating over range Readings displayed other than the readings described above are evidence of a problem and the test leads must be replaced before using the meter Failure to do so could result in damage to equipment and electrical shock If replacing the test leads does not solve the problem return the instrument for repair 4 Model 380363 Version 2 0 J uly 2005 Insulation Resistance Measurements Megohmmeter Tests Waming Do not perform Insulation Resistance measurements if AC Voltage is present on the device under test 1 Connect the red test lead to the VQ input terminal black lead to the COM terminal Set the function switch to the desired MQ test voltage position Connect the tips of the test leads to the equipment under test If there is a voltage present it will be displayed A repetitive beep and the flashing high voltage symbol 4 will be displayed if the voltage is over 30V 4 The display will show until the TEST button is pushed Press and hold the TEST button The upper right display shows the test voltage applied The main display shows the resistance If the display reads OL the measurement is beyond the range of the instrument 5 Keep the test leads connected to the equipment under test and release the TEST button The circuit will discharge through the meter Keep the test leads connected until the circuit is completely discharged and the upper right
11. ogarithmic scale and voltage on a linear scale The value always tracks the main display Maintenance Battery Replacement When the low battery symbol appears BT on the LCD the six 1 5V AA batteries must be replaced 1 Turn the meter off and remove the test leads Remove the four 4 Phillips head screws on the rear of the meter Remove the meter s rear cover Replace the batteries observing polarity ec Affix the rear cover and secure the rear screws Fuse Replacement If the meter turns ON but does not measure correctly check the internal fuse 1 Turn the meter off and remove the test leads 2 Remove the four 4 Phillips head screws on the rear of the meter 3 Remove the meter s rear cover 4 Check and replace the fuse if necessary 0 5A 600V fast blow 5 Affix the rear cover and secure the rear screws Cleaning Periodically wipe the case with a dry cloth Do not use solvents or abrasives to clean this instrument 7 Model 380363 Version 2 0 J uly 2005 Applications Measuring Power Tools and Small Appliances This section applies to any device under test that uses a line cord For double insulated power tools the meter s leads should be connected to the device s housing chuck blade etc and to the lines of the power cord Refer to the diagram Testing AC Motors Disconnect the motor from the line by disconnecting the wires from the motor terminals or opening the mains switch
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