Megger 835140 Instruction Manual
  1. Manuals
  2. Brands
  3. Megger Manuals
  4. Measuring Instruments
  5. 835140
  6. Instruction manual
Megger 835140 Instruction Manual

Megger 835140 Instruction Manual

Battery ground fault locator
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
Instruction Manual AVTM835140 
Battery Ground Fault Locator 
No. 835140 and 835140‐1
High Voltage Equipment 
Read the entire manual before operating. 
Aparato de Alto Voltaje 
Antes de operar este producto lea este manual enteramente. 
for 
 
 
 
 
 
 
 
 
 
M
400 Opportunity Way
Phoenixville, PA 19460 U.S.A.
Tel.: 610-676-8500
www.megger.com
AVTM835140 
Rev 4 
August 2022 

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the 835140 and is the answer not in the manual?

Questions and answers

Subscribe to Our Youtube Channel

Related Manuals for Megger 835140

Summary of Contents for Megger 835140

  • Page 1 AVTM835140  Rev 4  August 2022  Instruction Manual AVTM835140  for  Battery Ground Fault Locator  No. 835140 and 835140‐1 High Voltage Equipment  Read the entire manual before operating.  Aparato de Alto Voltaje  Antes de operar este producto lea este manual enteramente.                    400 Opportunity Way Phoenixville, PA 19460 U.S.A. Tel.: 610-676-8500 www.megger.com...
  • Page 2    ...
  • Page 3 Instruction Manual AVTM835140  for  Battery Ground Fault Locator  No. 835140 and 835140‐1...
  • Page 4 The information presented in this manual is believed to be adequate for the intended use of the product. If the product or its individual instruments are used for purposes other than those specified herein, confirmation of their validity and suitability must be obtained from Megger. Specifications are subject to change without notice.
  • Page 5 400 Opportunity Way Phoenixville, PA 19460 U.S.A. Tel.: 610-676-8500 www.megger.com...

  • Page 7: Table Of Contents

    TABLE OF CONTENTS  OPERATOR SAFETY ........................... 1 1.1 Description ............................1 1.2 Explanation Of Safety Symbols ......................1 1.3 Grounding ............................2 1.4 Power Cord And Fuses ........................2 GENERAL INFORMATION ........................ 3 2.1 Description ............................3 2.2 Features ............................. 3 2.3 Specifications ............................. 4 2.3.1 Test Signal Output ........................4 2.3.2 Withstand Capability .........................4 2.3.3 Loading ............................4...
  • Page 8 3.4 Repacking And Shipment ......................... 12 OPERATING INSTRUCTIONS ......................13 Panel Controls And Operating Functions ................... 13 4.2 Principle Of Operation ........................16 4.3 Safety Considerations ........................16 4.3.1 Output Lead Set ........................16 4.3.2 Input Sensor ..........................18 4.3.3 Recommended Operator Precautions ..................18 4.4 General Operating Procedure - Resistance &...
  • Page 9 Battery Ground Fault Locator  LIST OF FIGURES  Figure 4-1 – Panel Controls And Operating Functions ..............15 Figure 4-2 – Connection To A Battery System ................17 Figure 4-3 - Connection To Main Breaker Panel ................22 Figure 4-4 - Detecting The Total Resistance And Capacitance To Ground ........24 Figure 4-5 - Locating Ground Faults ....................28 Figure 4-6 - Locating Multiple Ground Faults ................30 Figure 4-7 - Battery System With Capacitive Loading ..............33...
  • Page 10 AVTM835140  Rev 4 (8/2022)  iv ...

  • Page 11: Operator Safety

    Refer to the following sections of this manual for operating specifications and procedures. 1.2   EXPLANATION OF SAFETY SYMBOLS  Megger uses, where applicable, the following IEC 417 symbols on its instruments: This symbol indicates that the operator of the instrument must refer to the instruction manual for further explanation and clarification.

  • Page 12: Grounding

    The power cord must be connected to a grounded supply system with proper electrical ratings, as indicated on the instrument. In the case of detachable power cords, only the cord supplied or specified by Megger should be used. WARNING  TO AVOID ELECTRIC SHOCK ALWAYS DISCONNECT THE POWER CORD FROM THE SUPPLY ...

  • Page 13: General Information

    2  GENERAL INFORMATION  2.1   DESCRIPTION  The Megger Battery Ground Fault Locator is a portable instrument used for detecting, tracing and locating ground faults on battery systems. The instrument’s operation is based on injecting a low frequency AC signal between the battery system and ground and then synchronously detecting the resulting current. The instrument is capable of tracing single or multiple ground faults on battery systems that are fully isolated, or resistance grounded.

  • Page 14: Specifications

    2.3   SPECIFICATIONS  2.3.1  TEST SIGNAL OUTPUT  60Hz Operation 50Hz Operation Shape: sinusoidal sinusoidal Frequency: 25Hz ±1Hz 21Hz ±1Hz Maximum Output Voltage: 3.5VAC (open circuit) 3.5VAC (open circuit) Maximum Output Current: 120mA (short circuit) 100mA (short circuit) Output Impedance for 25Hz: 66 ohms, nominal 78 ohms, nominal Equivalent D.C.

  • Page 15: Input Current Sensors

    Battery Ground Fault Locator  2.3.5  INPUT CURRENT SENSORS  For safety reasons only one of the following sensors should be used with this instrument.  STANDARD CLAMP-ON CURRENT SENSOR (835142) Maximum Physical Opening: 2.5 inches. Dielectric Strength: 1 kV AC. Maximum DC Bias: 25A. Maximum AC Ripple Current: 0.5A. MINI CLAMP-ON CURRENT SENSOR (OPTIONAL, 835146) Maximum Physical Opening: 1 inch. Dielectric Strength: 1 kV AC.

  • Page 16: Sensitivity

    The Battery Ground Fault Locator is capable of locating single or multiple faults, without subsequent troubleshooting, if output load impedance is higher than 66 ohms in 60Hz version (78 ohms for 835140-1). Below this value accuracy deteriorates. The capacitance to ground of the system affects sensitivity and accuracy.

  • Page 17: Instrument Power Supply

    Battery Ground Fault Locator  2.3.11  INSTRUMENT POWER SUPPLY  Internal, sealed, lead-acid rechargeable battery giving a minimum of 8 hours of continuous operation on full charge. Internally protected against charge exhaustion and overcharging by a temperature compensated charging circuit, 10 - 12 hour recharge time. Instrument may be operated while recharging through standard CEE three-pin line socket with built-in fuse and spare.

  • Page 18: Operation

    The customer shall prepay shipping charges for units returned to Megger, and Megger shall pay for the return of the required or replaced unit to the customer, repair or replace (at Megger’s option) the unit or subassembly...
  • Page 19 This warranty covers the cost of repairing or replacing faulty components at Megger’s option, but not the cost of travel and living expenses of service personnel for work completed in the field. Any field service trips will be subject to inspection of the Megger service representative.
  • Page 20 AVTM835140  Rev 4 (8/2022)  10 ...

  • Page 21: Installation

    3  INSTALLATION  3.1  UNPACKING AND INSPECTION  Prior to shipment this instrument was electrically tested and mechanically inspected and found to meet specifications and be free of mechanical defects. After unpacking the instrument, visually inspect the instrument and accessories for damage. If evidence of damage is present, YOU must contact the carrier who transported the unit and file a claim in writing.

  • Page 22: Repacking And Shipment

    3.4  REPACKING AND SHIPMENT  To insure proper shipment of this instrument it is recommended that the original reusable container and packing material be retained. If being returned for calibration or service, please attach a card to the instrument specifying the owner, model and serial number and service required. AVTM835140  Rev 4 (8/2022) ...

  • Page 23: Operating Instructions

    4  OPERATING INSTRUCTIONS  4.1  PANEL CONTROLS AND OPERATING FUNCTIONS  Refer to Figure 4-1. 1. Line Input Socket - Standard input for line cord. Fuse plus spare is located above socket. 2. AC Line - Illuminates when the input plug is connected to a live circuit. 3.
  • Page 24 15. Sensor Output - This is a replica of the current being sensed by the Current Sensor, after it has passed through a 25Hz (21Hz for 835140-1) notch filter. It allows the operator to monitor battery system current ripple using an oscilloscope or recorder.

  • Page 25: Figure 4-1: Panel Controls And Operating Functions

    Battery Ground Fault Locator  Figure 4-1: Panel Controls and Operating Functions AVTM835140  Rev 4 (8/2022)  15 ...

  • Page 26: Principle Of Operation

    4.2   PRINCIPLE OF OPERATION  The Megger Battery Ground Fault Locator measures ground fault resistance in battery systems by: 1. Injecting an AC voltage between station ground and battery system. 2. Measuring the resulting circulating current with a clamp-on C.T. used as the current sensor.

  • Page 27: Figure 4-2: Connection To A Battery System

    Battery Ground Fault Locator  Figure 4-2: Connection to a Battery System Connect to battery system as follows: Green clip to system ground. This is the safety case STEP 1. ground. STEP 2. Fused black clip to system ground. NOTE: This is output signal return. STEP 3.

  • Page 28: Input Sensor

    NOTE: Warning >30VDC red LED should turn off when discharge is complete. STEP 3. Remove fused black clip. STEP 4. Remove green clip. 4.3.2  INPUT SENSOR  Clamp-on current sensor is first connected to instrument. Iron core of sensor is electrically isolated from its output. Contact of iron core with live D.C. bus will not cause an electrical hazard.
  • Page 29 Battery Ground Fault Locator  If power switch is in 'on' position when commencing, the unit may have the 'auto-off' enabled. To reset, simply place the switch to 'off ' and then back to the 'on' position. 2. Connect "Current Sensor" and "Output Lead Set" to the instrument. 3.

  • Page 30: Led Measurement Status Indicators

    STEP 1. Disconnect red clip from battery bus bar and if "Warning > 30VDC" red LED illuminates, momentarily connect it to system ground to turn off this LED STEP 2. Disconnect black clip from battery ground. STEP 3. Disconnect green clip from station ground. 4.4.2   LED MEASUREMENT STATUS INDICATORS ...

  • Page 31: Measurement Of Capacitance

    Battery Ground Fault Locator  4.4.3  MEASUREMENT OF CAPACITANCE  Capacitance measurements are done in exactly the same manner as outlined in steps 1-10 with the exception of step 5; where the switch is set to 'capacitance'. Step 6 will give the operator total capacitance to ground for the battery system. This should be measured prior to doing resistance measurements to ensure all readings will be totally valid.

  • Page 32: Figure 4-3: Connection To Main Breaker Panel

    Figure 4-3: Connection to Main Breaker Panel AVTM835140  Rev 4 (8/2022)  22 ...

  • Page 33: Determining The Total Resistance Or Capacitance To Ground

    Battery Ground Fault Locator  4.5  DETERMINING THE TOTAL RESISTANCE OR CAPACITANCE TO GROUND  Refer to Figure 4-4 for further clarification of procedure. Most battery systems are equipped with detectors that will indicate the presence of a ground fault. If this indication is not available or if an operator wants to verify its proper operation, the following procedure should be used.

  • Page 34: Figure 4-4: Detecting The Total Resistance And Capacitance To Ground

    Figure 4-4: Detecting the Total Resistance and Capacitance to Ground AVTM835140  Rev 4 (8/2022)  24 ...

  • Page 35: Procedure For Locating Ground Faults

    Battery Ground Fault Locator  4.6   PROCEDURE FOR LOCATING GROUND FAULTS  Refer to Figure 4-5 for further clarification of procedure. 4.6.1  GENERAL  When attempting to find the location of a ground fault (or multiple faults), it is important to conduct the tests in a progressive and orderly manner. This means starting at a point closest to the battery (mains and mains breaker panel) and moving towards the individual loads.
  • Page 36 STEP 2 1. Clamp C.T. on positive battery lead. Indication on meter "> 100 Kohms", therefore, no serious fault on the positive side of battery system is present. STEP 3 1. Clamp C.T. on negative battery lead. Indication on meter "5 Kohms", therefore, a total resistance of 5 Kohms to ground exists on the negative battery lead between the C.T.
  • Page 37 Battery Ground Fault Locator  STEP 7 1. Clamp C.T. as per Figure 4-5. Indication on meter "5 Kohms", therefore, the total resistance found in step 3 is somewhere on this branch between this point and the connected load. STEP 8 - MOVE TO SECONDARY BREAKER PANEL 1.

  • Page 38: Figure 4-5: Locating Ground Faults

    Figure 4-5: Locating Ground Faults AVTM835140  Rev 4 (8/2022)  28 ...

  • Page 39: Multiple Faults

    Battery Ground Fault Locator  4.7   MULTIPLE FAULTS  Refer to Figure 4-6 for further explanation of procedure. 4.7.1  GENERAL  When dealing with older battery systems, it is very likely that more than one fault is present at any one time on the battery system. To locate multiple faults, it is important to note the exact values at each step and location.

  • Page 40: Figure 4-6: Locating Multiple Ground Faults

    The resistance between secondary breaker panel and main breaker panel is therefore 5 Kohms. Figure 4-6: Locating Multiple Ground Faults AVTM835140  Rev 4 (8/2022)  30 ...

  • Page 41: Battery Systems With Capacitive Loading (Transient Suppression)

            For a system where the capacitance to ground is 10µF and DF = 1% (0.01), the equivalent ground fault resistance will be, 835140   Kohms      ...
  • Page 42 From the results of this calculation, it can be seen that on its own, 10μF capacitance having a DF of 1% (0.01) will register on the Battery Ground Fault Locator. This may not always be the situation, as the DF of capacitors used for this application should be higher than 1%.

  • Page 43: Accuracy Vs Capacitive Loading

    Battery Ground Fault Locator  Figure 4-7: Battery System with Capacitive Loading 4.8.2  ACCURACY vs CAPACITIVE LOADING  The instrument's ability to resolve the resistive signal component deteriorates with an increase of capacitance in the measuring loop. This is mostly due to phase angle uncertainty in the instrument. Below is a table which can be used as a guideline when the operator wishes to determine the highest resistance value that can be measured with reasonable accuracy, in the presence of capacitance.

  • Page 44: Power Frequency And Harmonic Ripple

    The results of this interference will be a fluctuating meter on the BGL. The meter will swing back and forth in a cyclical manner. This erratic behavior will result in an inability to resolve resistive ground faults on this particular branch. The BGL is protected against many annunciator and switching load problems by way of a special "sample &...

  • Page 45: Sensor Output

    The "Sensor Output" provides a replica signal of the current sensed by the clamp- on sensor. Absent from this replica is DC, and the injected 25Hz (21Hz for 835140- 1) current components. This output should be examined in all situations when "INPUT OVERLOAD"...

  • Page 46: Service And Maintenance

    Field service and calibration requirements should be referred to the nearest Megger sales office. AVTM835140  Rev 4 (8/2022) ...
  • Page 47 Battery Ground Fault Locator  AVTM835140  Rev 4 (8/2022)  37 ...

  • Page 48: Documentation

    6  DOCUMENTATION  The following drawings are included at the end of this section for reference purposes only. DRAWING NUMBER TITLE C35140-102 Schematic, Chassis C35140-103 Block Diagram, Chassis A35145-101 Schematic, Fault Simulator AVTM835140  Rev 4 (8/2022)  38 ...
  • Page 49 Battery Ground Fault Locator  AVTM835140  Rev 4 (8/2022)  39 ...
  • Page 50 AVTM835140  Rev 4 (8/2022)  40 ...
  • Page 51 Battery Ground Fault Locator  AVTM835140  Rev 4 (8/2022)  41 ...

This manual is also suitable for:

835140-1

Table of Contents