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Megohmmeter Model 1000N (Catalog# 185.100) Repair and Calibration Manual

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Megohmmeter Model 1000N (Catalog# 185.100) Repair and Calibration Manual Rev. 8 3/04 MEGOHMMETER MODEL 1000N (CATALOG# 185.100) REPAIR AND CALIBRATION MANUAL MODEL 1000N REPAIR AND CALIBRATION MANUAL CAT. #185.100 TABLE OF CONTENTS Repair and Technical Services....................................................................................... 3 Introduction..................................................................................................................... 4 Specific Features............................................................................................................ 4 Principal Characteristics ................................................................................................. 4 Specifications ..................................................................................................................6 Operation........................................................................................................................ 7 Calibration .................................................................................................................... 11 Taking the Instrument Apart ......................................................................................... 14 Troubleshooting............................................................................................................ 17 Summary of Malfunctions ............................................................................................. 20 Component Parts List................................................................................................... 21 Mechanical Parts List ................................................................................................... 26 Test Points ................................................................................................................... 28 Power Board Schematic and Specifications ................................................................. 29 Main Board ................................................................................................................... 30 Measure Board............................................................................................................. 31 High Voltage Board ...................................................................................................... 32 Schematics........................................................................................................... 33 & 34 Revision Description Date Approved 1 Updated Specs May 21, 1996 JPM 2 Updated Specs July 17, 1997 JPM 3 Updated Specs September 23, 1998 JPM 4 Updated Specs June 8, 1999 JPM 5 Added Power Supply Schematic and Specs August 25, 2000 JPM 6 Added changes to schematics November 13, 2000 JPM 7 Modified Board Drawings June 7, 2002 JPM 8 Z4, Z7 and Z9 changed to OP07C March 13, 2004 JPM 2 REV. 7: March 13, 2004 FILE LOCATION: Manuals - Cal. Man - 1000MAN.DOC 4/21/2005 MODEL 1000N REPAIR AND CALIBRATION MANUAL CAT. #185.100 REPAIR AND CALIBRATION NOTE: Any attempts to repair and/or maintain this instrument, other than replacement of fuses and batteries, voids the warranty of the instrument. The presence of high voltages at certain locations requires servicing of this instrument by qualified personnel. It is recommended that the instrument be sent to an authorized service center. To guarantee that your instrument complies with the factory specifications, we recommend that the unit be submitted to our factory service center at one year intervals for recalibration, or as required by other standards. For instrument repair and/or calibration, please call our factory at (800) 945-AEMC. CHAUVIN ARNOUX®, Inc. d.b.a. AEMC® Instruments 15 Faraday Drive • Dover, NH 03820 USA (800) 945-2362 • (603) 749-6434 • Fax: (603) 742-2346 (Or contact your authorized distributor.) Estimates for repairs, normal recalibration, and calibration traceable to N.I.S.T. are available. All customers must call for an authorization number before returning any instrument. TECHNICAL AND SALES ASSISTANCE If you are experiencing any technical problems, or require any assistance with the proper use or application of this instrument, please call our technical hotline: CHAUVIN ARNOUX®, Inc. d.b.a. AEMC® Instruments (800) 343-1391 • (508) 698-2115 • Fax: (508) 698-2118 www.aemc.com 3 REV. 7: March 13, 2004 FILE LOCATION: Manuals - Cal. Man - 1000MAN.DOC 4/21/2005 MODEL 1000N REPAIR AND CALIBRATION MANUAL CAT. #185.100 INTRODUCTION The Model 1000N Megohmmeter is a portable instrument which is essentially intended for performing insulation tests upon various components of electrical systems and equipment. The instrument allows completion of measurements according to multiple voltage levels (step voltage method), making it possible for the user to evaluate insulation quality and to plan preventive maintenance accordingly (especially for motors). SPECIFIC FEATURES: • If a linear response were to be adopted for resistance and conductance, a high number of scales would be required on account of the extent of the measuring range which must be cover in practice, from 1 MΩ to 1000 GΩ. The use of logarithmic response circuitry reduces the number of scales to two. Each scale covering three decades. The accuracy is typically on the order of ± 5% over the entire range. • Selection of the test voltages does not cause the measuring range to change. It is very easy to determine the influence of voltage upon insulation. • An additional range is provided to cover from 1 kΩ to 1 MΩ. This range uses a constant current source (1 mA) to perform the measurement. The maximum open voltage is limited to approximately 1100 V. • A voltmeter range covering from 0 to 600 V AC or DC allows the user to verify whether or not the circuit where the insulation must be tested is energized. • Insulation testing and voltmeter functions are accompanied by a continuity test range from 0.1Ω to 100Ω. The logarithmic scale provides excellent accuracy between 0.1Ω to 1Ω. A fuse is used for overload protection in case of incorrect measuring procedures. PRINCIPAL FEATURES: Insulation Testing: • Test voltages - The rotary selector switch allows the choice of five voltages: 50 V, 100 V, 250 V, 500 V, 1000 V. • Ranges for each test voltage MΩ: 1 MΩ to 1000 MΩ (typical accuracy: ± 5% of reading, max: ± 10% of reading) GΩ: 1 GΩ to 1000 GΩ (typical accuracy: ± 5% of reading, max: ± 10% of reading) KΩ: 1 KΩ to 1000 KΩ (typical accuracy: ± 5% of reading, max: ± 10% of reading) NOTE: From 100 GΩ to 1000 GΩ, the typical accuracy is ± 10% and max. is ± 20% of reading on the 50 V range. 4 REV. 7: March 13, 2004 FILE LOCATION: Manuals - Cal. Man - 1000MAN.DOC 4/21/2005 MODEL 1000N REPAIR AND CALIBRATION MANUAL CAT. #185.100 Continuity Testing: 0.1Ω to 100Ω (typical accuracy: ± 5% of reading, max: ± 10% of reading or 5 mΩ) The logarithmic scale is the same for the Ω and KΩ range. The 0.1Ω is calibrated at the output terminal of the instrument. You need to subtract the resistance value of the leads from your measurement if you need the accuracy under 10Ωs. DC or AC Voltage Measurements: In order to ensure that the system under test is not energized, the instrument functions as a voltmeter as soon as it is connected, provided the push-to-measure button has not yet been pressed. This is the case for every range selected. Scale: 0 to 600V AC or DC: accuracy: 3% of full scale Time Constant: K M G Charging time (R reading) x (C reading) 0.04 Sec / µF 4 Sec / µF Discharging time 0.1 Sec / µF or 0.3 Sec / µF to decrease below 50 V Safety Features: • This instrument is capable of withstanding overloads of up to 600 V for any selected function. • The continuity range is protected by a fuse inserted in the "G" (Guard) terminal and is accessible when the battery compartment is removed. Influence: • Temperature: Twice the accuracy per 10° C variation Supply voltage: Half the accuracy for battery voltages between 9 and 13 Volts • Humidity: No significant influence up to 40° C and up to 70% relative humidity Dielectric Strength: • 4000V RMS at 50 Hz for 1 minute between all input terminals and any accessible metal portions of the instrument. • Model with AC power supply accessory: Add test at 4000V RMS at 60 Hz for 1 minute between the AC outlet and any accessible metal portions of the instrument. 5 REV. 7: March 13, 2004 FILE LOCATION: Manuals - Cal. Man - 1000MAN.DOC 4/21/2005 MODEL 1000N REPAIR AND CALIBRATION MANUAL CAT. #185.100 SPECIFICATIONS: VOLTAGE TESTS (SAFETY CHECK) ELECTRICAL VOLTAGE RANGE: 0 to 600 V DC INSULATION TESTS ACCURACY: 3% of full scale DC TEST VOLTAGE: 50, 100, 250, 500, 1000 V GENERAL SPECIFICATIONS MEGOHM RANGE: AUDIBLE TEST SIGNAL: Ten beeps per minute for For each test voltage two direct reading ranges insulation and resistance tests; continuous tone for 1 to 1000 MΩ continuity test reading ≤ 200Ω 1 to 1000 GΩ (1,000,000 MΩ) POWER SUPPLY: Eight 1.5 V "AA" alkaline batteries SHORT CIRCUIT CURRENT: 5 mA (max) (NEDA 15A). Typical battery life: 350 one-minute tests; power consumed only when test button is 5% of reading typical ACCURACY: depressed; built-in battery check by green LED. 15 % of reading between 100 MΩ to 1000 GΩ on the 50V range OPTION: 110/220 V selectable, 47 to 400 Hz AC supply module 1000 MΩ range: 0.3 s/µF CHARGING TIME: 4000 V AC, 60 Hz, 1 min 1000 GΩ range: 4 s/µF DIELETRIC TEST: METER MOVEMENT: Rugged taut band suspension DISCHARGE TIME: Automatic discharge when test button is released; 0.1 DIMENSIONS: 7.7 X 5.2 X 3.75" (196 X 132 X 95 mm) s/µF WEIGHT: 2.2 lbs (1 kg) SCALE: Two large overlapping scales: 4.7" (119 mm) for
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