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Table of Contents
Related Manuals for AEMC 3711
Summary of Contents for AEMC 3711
- Page 1 Clamp-On Ground Resistance Tester Models 3711 and 3731 USER MANUAL Model 3711 Model 3731 ® ® GROUND TESTER GROUND TESTER I N S T R U M E N T S I N S T R U M E N T S...
- Page 2 Statement of Compliance ® ® Chauvin Arnoux , Inc. d.b.a. AEMC Instruments certifies that this instrument has been calibrated using standards and instruments traceable to international standards. We guarantee that at the time of shipping your instrument has met its published specifications.
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Page 3: Limited Warranty
Limited Warranty The Models 3711 and 3731 are warranted to the owner for a period of one year from the date of original purchase against defects in ® manufacture. This limited warranty is given by AEMC Instruments, not by the distributor from whom it was purchased. This warranty is void if the unit has been tampered with, abused or if the defect is related to ®... -
Page 4: Table Of Contents
Body Design ..................7 Electrical Specifications ................8 Ground Resistance................8 Ground or Leakage Current..............8 Mechanical Specifications.................8 Safety Specifications.................9 Model 3711 Controls ................10 Model 3731 Controls ................11 Digital Display Features ................12 Additional Features of the Model 3731..........13 Function Controls ..................14 On/Off ....................14 Auto-Off ....................15 Hold .....................15... - Page 5 Programming Summary ................21 Principle of Operation................22 Field Applications ..................24 Pole Ground Rods ................24 Service Entrance or Meter..............25 Pad Mounted Transformer..............25 Pad Mounted Transformer..............26 Transmission Towers ................27 Central Office Locations ..............27 Service Panel ..................28 Phone Pedestal ...................29 Above Telephone Space ..............31 General Measurement Notes ..............31 Operating Reference Card ..............32 Field Test Loop..................32...
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Page 6: Warning
Ground Resistance Tester Models 3711 and 3731 Warning These safety warnings are provided to ensure the safety of personnel and proper operation of the instrument. • The instrument must not be operated beyond its specified operating range. • Safety is the responsibility of the operator. -
Page 7: Definition Of Measurement Categories
Save the damaged packing container to substantiate your claim. Packaging The Model 3711 (Cat. #2117.60) and Model 3731 (Cat. #2117.61) are shipped with a hard carrying case, one 9V battery (not installed), a user manual with warranty registration and a field test loop. The manual, warranty card, and test loop are located behind the “egg crate”... -
Page 8: Description
Clamp-on ground resistance testers are used in multi-grounded systems without disconnecting the ground under test. The Models 3711 and 3731 simply clamp around the ground conductor or rod and measure the resistance to ground. By performing measurements on intact ground systems, the user also verifies the quality of the grounding connections and bonds. -
Page 9: Jaw Design
Ground Resistance Tester Models 3711 and 3731 Jaw Design The probe head, or jaw, is a key component in the measurement and overall product performance. Considerable research and development were dedicated to ensuring its performance, reliability and versatility. The large jaw has an inner opening diameter of 1.25" (32mm) permitting use on tight ground conductors on poles and in manholes. -
Page 10: Electrical Specifications
Ground Resistance Tester Models 3711 and 3731 Electrical Specifications Ground Resistance Measurement Range Range Resolution Accuracy* 0.1 to 1.00Ω 0.01Ω ± (2% R ± 0.02Ω) 1.0 to 50.0Ω 0.1Ω ± (1.5% R ± 0.1Ω) 50.0 to 100.0Ω 0.5Ω ± (2.0% R ± 0.5Ω) Autoranging 100 to 200Ω... -
Page 11: Safety Specifications
Ground Resistance Tester Models 3711 and 3731 ® Case Material: Lexan 920A (UL94V2) or equivalent Jaw Cover Material: ® Lexan with 10% fiberglass charge (UL94V0) or equivalent ® LCD Cover Material: Clear Lexan (UL94V1) or equivalent Color: Gray body, red jaws Jaw Window Diameter: 1.25”... -
Page 12: Model 3711 Controls
Ground Resistance Tester Models 3711 and 3731 Model 3711 Controls Model 3711 ® GROUND TESTER I N S T R U M E N T S NOISE – Ω Figure 1 1. Head Assembly: Consists of 4. ON/OFF: Power ON or OFF,... -
Page 13: Model 3731 Controls
Ground Resistance Tester Models 3711 and 3731 Model 3731 Controls 1. Head Assembly: Consists of two individually shielded magnetic cores. 2. Hold: Freezes last measured value on the display. 3. Display: 3000 count LCD, function indicators. 4. ON/OFF: Power ON or OFF, activates display self test at power-up. -
Page 14: Digital Display Features
Ground Resistance Tester Models 3711 and 3731 Digital Display Features NOISE R .1 HOLD – Figure 3 Displayed when the beeper is active. To turn the beeper On/Off, push ON & Ω together at power-up. The beeper is active when displayed. -
Page 15: Additional Features Of The Model 3731
Memory recall register. Displays the numbered value being recalled from memory (1-99). Note: Models 3711 and 3731 share the same LCD and display all segments at power-up. Functions not available on the 3711 are displayed at power-up. -
Page 16: Function Controls
Function Controls Ω Model 3711 and 3731 share common functions (On/Off, A, , Auto-off, Buzzer disable, Hold). Even though the Model 3711 is shown in the examples for these functions, the controls will respond identically for the Model 3731. On/Off The ON/OFF push-button, when pushed actuates power on or power off with an audible control tone. -
Page 17: Auto-Off
Ground Resistance Tester Models 3711 and 3731 Auto-Off The instrument will shut off automatically after five minutes of non-use. The instrument will issue a short beep 15 seconds prior to shutting down and the LCD flashes once per second. The odel 3711 ®... -
Page 18: Resistance
Upon initial power-on, the Ω function is chosen by default. Model 3711 ® G OUND TESTE I N S T U M E N T S The Models 3711 and 3731 will track down to 0.07Ω and indicate below 0.1Ω (Fig. 10). Accuracy defined below 0.1Ω. -
Page 19: Current
Ground Resistance Tester Models 3711 and 3731 Current Press A to enter the current function. True RMS current measurements are possible up to 30.00A (Fig. 12). Above 30Arms, OL will be displayed and the test must be discontinued. The beeper is also activated during OL. -
Page 20: Alarm
Ground Resistance Tester Models 3711 and 3731 Alarm Turn the Alarm on/off by pressing the AL odel 3731 ® GROUND TESTER button. The alarm feature provides a I N S T R U E N T S continuous audible warning (when beeper is active) and visual indications when a setpoint has been reached (Fig. -
Page 21: Changing The Alarm Trigger
Ground Resistance Tester Models 3711 and 3731 Changing the Alarm Trigger The Model 3731 alarm may be set to trigger above or below a setpoint. Follow the procedure below for setting the alarm trigger. 1. The instrument must be OFF and disconnected from any conductor. -
Page 22: Memory
Ground Resistance Tester Models 3711 and 3731 Memory To activate the Memory feature, press the A odel 3731 ® and ON buttons together at power-up (Fig. GROUND TESTER I N S T R U E N T S 16). MEM will be displayed. -
Page 23: Function Access Summary
Ground Resistance Tester Models 3711 and 3731 odel 3731 odel 3731 ® ® GROUND TESTER GROUND TESTER I N S T R U E N T S I N S T R U E N T S Ω Ω Figure 18... -
Page 24: Principle Of Operation
Ground Resistance Tester Models 3711 and 3731 Principle of Operation Typically grounded distribution system may be simulated by the basic circuit shown in Fig. 20 or an equivalent circuit, shown in Fig. 21. If voltage (V) is applied to any measured grounding electrode Rx through a... - Page 25 Ground Resistance Tester Models 3711 and 3731 Figure 20 Figure 21 - 23 -...
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Page 26: Field Applications
Ground Resistance Tester Models 3711 and 3731 Field Applications Pole Ground Rods Remove any molding covering the ground conductor, and provide sufficient room for the jaws of the clamp-on. The jaws must be able to close easily around the conductor. The jaws can be placed around the ground rod itself. -
Page 27: Service Entrance Or Meter
Ground Resistance Tester Models 3711 and 3731 Note: A high reading or OL indicates one or more of the following: A. Poor ground rod B. Open ground conductor C. High resistance bonds on the rod or splices on the conductor; watch for buried split butts, clamps, and hammer-on connections. -
Page 28: Pad Mounted Transformer
Ground Resistance Tester Models 3711 and 3731 Pad Mounted Transformer Observe all safety requirements - High voltage may be present! Locate and number all rods (usually only a single rod is present). If the ground rods are inside the enclosure, refer to Fig. 25 and if they are outside the enclosure, refer to Fig. -
Page 29: Transmission Towers
Ground Resistance Tester Models 3711 and 3731 Transmission Towers Observe all safety requirements - Dangerously high voltage may be present! Locate the ground conductor at the base of the tower. Many different configurations exist. Care should be taken when searching for the ground conductor. -
Page 30: Service Panel
The Electric Utility Neutral should be the principle conductor of the low- impedance signal return path required to test the resistance of this ground electrode with the Model 3711/3731. This can be verified by removing other ground connections, noting if any changes appear in the readings. -
Page 31: Phone Pedestal
After noting the ground current, select the ground resistance range “Ω” and measure the resistance directly. The reading you measure with the 3711/3731 indicates the resistance of not just the rod, but also the connection to the sheath ground and all bonding connections between the sheath bond and the rod. - Page 32 Ground Resistance Tester Models 3711 and 3731 Phone Pedestal round Bar Sheath Connection round level round Figure 29 Phone 1. Remove ground bar Pedestal connection to pedestal rod 2. Extend pedestal rod lead to the ground bar using a temporary jumper...
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Page 33: Above Telephone Space
Ground Resistance Tester Models 3711 and 3731 Above Telephone Space Select the current range “A.” Clamp onto the ground wire and measure the current (Fig. 31). The maximum current range is 30A. If the ground current exceeds 5A, resistance measurements are not possible. Do not proceed further with the measurement. -
Page 34: Operating Reference Card
Ground Resistance Tester Models 3711 and 3731 Operating Reference Card Included with the Model 3711 and 3731 you will find an operating reference card like the one shown here. This card summarizes all the features of the Model 3711 and 3731. -
Page 35: Commonly Asked Questions For
Ground Resistance Tester Models 3711 and 3731 Commonly Asked Questions for Clamp-on Ground Resistance Measurements Q. Can the Clamp-on method be used effectively on high tension towers despite the distance or spacing between them? A. Yes. Extended distances will not adversely affect the measurement results. -
Page 36: Maintenance
Ground Resistance Tester Models 3711 and 3731 Q. Can the clamp-on method be used for substation grid resistance testing? A. It depends. It can be used as long as the instrument can be clamped onto a point on the grounding system at a common point where it ties to the system neutral. -
Page 37: Battery Replacement Procedure
Ground Resistance Tester Models 3711 and 3731 Battery Replacement Procedure The Clamp-On Ground Resistance Testers are powered by a single 9V battery. The battery replacement indicator will display continuously when battery replacement is required. Recommended replacement type is Alkaline (IEC 6LF22, 6LR61 or NEDA 1604A). -
Page 38: Repair And Calibration
Ground Resistance Tester Models 3711 and 3731 Repair and Calibration To ensure that your instrument meets factory specifications, we recommend that it be submitted to our factory Service Center at one-year intervals for recalibration, or as required by other standards or internal procedures. - Page 40 ® ® Chauvin Arnoux , Inc. d.b.a AEMC Instruments 15 Faraday Drive • Dover, NH 03820 USA www.aemc.com 99-MAN 100218 v11 02/10...