Biddle 246100_UG 电路图.pdf

AVTM246100B Revision B June 2003 Instruction Manual AVTM246100B for Battery Ground Fault Tracer Patent No. 4,546,309 HIGH-VOLTAGE EQUIPMENT Read this entire manual before operating. APARATO DE ALTO VOLTAJE Ante de operar este producto lea este manual enteramente. M Valley Forge Corporate Center 2621 Van Buren Avenue Norristown, PA 19403 U.S.A. 610-676-8500 (Telephone) 610-676-8610 (Fax) RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 Battery Ground Fault Tracer Instruction Manual RadioFans.CN 收音机爱 好者资料库 Copyright 2003 by Megger. All rights reserved. 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. Refer to the warranty information below. Specifications are subject to change without notice. WARRANTY Products supplied by Megger are warranted against defects in material and workmanship for a period of one year following shipment. Our liability is specifically limited to replacing or repairing, at our option, defective equipment. Equipment returned to the factory for repair must be shipped prepaid and insured. Contact your Megger representative for instructions and a return authorization (RA) number. Please indicate all pertinent information, including problem symptoms. Also specify the serial number and the catalog number of the unit. This warranty does not include batteries, lamps or other expendable items, where the original manufacturers warranty shall apply. We make no other warranty. The warranty is void in the event of abuse (failure to follow recommended operating procedures) or failure by the customer to perform specific maintenance as indicated in this manual. M Valley Forge Corporate Center 2621 Van Buren Avenue Norristown, PA 19403 U.S.A. 610-676-8500 (Telephone) 610-676-8610 (Fax) i Contents 1 INTRODUCTION.1 About the BGFT.1 How the BGFT Works.2 Applications for the BGFT.2 Upon Receipt of the BGFT.3 Safety First.4 How to Use This Manual.4 Typographic Conventions.4 2 SAFETY.5 Overview.5 Connection to Power Source.6 Fuse Replacement.7 3 CONTROLS, INDICATORS AND CONNECTORS.9 Overview.9 Transmitter (Figure 2).10 Receiver (Figure 4).12 Current Probe.13 4 OPERATION.15 General.15 Transmitter Connections.16 Applying Transmitter Power.17 Applying Transmitter Test Voltage.18 Receiver Connections and Applying Power.19 Defining The Fault.20 Bridge Operation.21 Tracing The Fault.22 Instrument Shutdown Procedure.22 5 APPLICATION NOTES.23 6 MAINTENANCE the other items are housed in a separate accessories bag. The Battery Ground Fault Tracer locates ground faults in ungrounded dc battery systems. Various standards require action when the impedance between any battery polarity and earth ground falls below a specified limit. In the case of nuclear-fueled plants, the Nuclear Regulatory Commission (NRC) requires audits and appropriate action when this impedance is deemed unsafe. Other facilities come under the guidelines of the National Electric Code, NFPA, IEEE standards, and OSHA requirements for safe operation of dc battery systems in an ungrounded environment. M 2 AVTM246100B Rev B June 2003 How the BGFT Works The Battery Ground Fault Tracer applies a 20 Hz signal between the battery bus and station ground. This is accomplished by connecting the transmitter via the source leads to an accessible battery bus and to a ground bus located in a distribution cabinet. A two-step process then begins to identify both the magnitude and location of the fault. First, suspect feeder cables are identified by measuring the flow of fault current to ground on all the output circuits from the cabinet, and then a bridge balance measurement is performed to determine the value of capacitance and resistance of the suspected ground fault. The resistance and capacitance bridge located on the transmitter is used to determine the value of the fault impedance in real and imaginary terms (resistance and capacitive reactance) while the amplitude of the signal current injected into the suspect feeder cable is monitored with the receiver. Three stages of amplification can be selected to identify and find faults to 399 k. The red feedback wire (supplied) is used as a canceling feature for the injected signal as compared with the bridge selected impedance. Isolating the fault to a specific location may require moving the equipment downstream in a distribution system. Once a fault resistance is quantified, the bridge and feedback portion of the procedure can be dismissed and the fault can be tracked by evaluating feeder lines of a subpanel. If the current value decreases after several steady or increasing readings, then the location is in the opposite direction. Applications for the BGFT The BGFT, Battery Ground Fault Tracer, can find ground faults in ungrounded battery systems in: ? Substations ? Generating Stations ? UPS Systems ? Any other ungrounded dc system For information about other installations that might benefit from impedance testing, contact Megger. INTRODUCTION 3 AVTM246100B Rev B June 2003 Upon Receipt of the BGFT Check the equipment received against the packing list to ensure that all materials are present. Notify Megger of any shortage. Telephone (610) 676-8500. Examine the instrument for damage received in transit. If any damage is discovered, file a claim with the carrier at once and notify Megger or its nearest authorized sales representative, giving a detailed description of the damage. This instrument has been thoroughly tested and inspected to meet rigid specifications before being shipped. It is ready for use when set up as indicated in this manual. The BGFT instrument is shown in Figure 1. The BGFT includes the following components and accessories. ? transmitter ? receiver with 9-volt battery ? current source leads ? clamp-on current sensor (CT) ? feedback loop ? line cord ? instruction manual Figure 1: Battery Ground Fault Tracer and Accessories M 4 AVTM246100B Rev B June 2003 Safety First Be sure to read the safety information in Section 2 thoroughly and observe all safety precautions and recommendations. How to Use This Manual Typographic Conventions Figures and tables are numbered in sequence by section. Numbered lists show procedural steps. Bullets list items and options. Buttons represent elements on the BGFT control panel. Cautions alert you to possible damage to equipment. G G CAUTION Never allow water to enter the case of the BGFT. Warnings alert you to conditions that are potentially hazardous to people. F F WARNING Always power off and disconnect the BGFT before cleaning it. Notes provide important information. NOTE: Very high impedances exhibit low resolution readings on the receiver. To obtain better resolution, wrap an additional turn around the clamp-on jaws of the current probe thereby doubling the fault current. Remember to divide the bridge capacitance by the number of turns and to multiply the bridge resistance by the number of turns to identify the fault impedance. Margin notes offer extra information and assistance. M 5 AVTM246100B Rev B June 2003 2 SAFETY Overview The BGFT and its recommended operating procedures have been designed with careful attention to safety. However, it is not possible to eliminate all hazards from electrical test equipment or to foresee every possible hazard that may occur. The user not only must follow the safety precautions contained in this manual, but also must carefully consider all safety aspects of the operation before proceeding. It should be understood that any use of electricity inherently involves some degree of safety hazard. While every effort has been made by Megger to reduce the hazard, the user must assume responsibility for his own safety. Any work on large batteries is hazardous and requires constant attention to safety; particularly guard against the possibility of acid spills, explosion, and electrical shock. The responsibility of the user is not limited to his/her own safety; he/she must also be responsible for all persons in the vicinity. The distribution system to which the Battery Ground Fault Tracer is connected can be extensive and therefore the user must be aware of the consequences of applying up to 50 Vac to the dc system and the effect on the operation and safety of the entire system. The BGFT has been designed to the IEC-1010-1 safety standards. Observe all industry standard safety rules for tracing ground faults. ? The Battery Ground Fault Tracer is designed for connection to energized systems. Keep the power on/off switch set to 0 (off) when making connections or disconnections at the battery. The output of the Battery Ground Fault Tracer and the system to which it is connected are sources of high voltage. Always wear rubber gloves during these operations. ? Safety is the responsibility of the user. ? The purpose of this equipment is limited to use as described in this manual. Do not use the equipment or its accessories for any purpose other than specifically described. ? Do not operate in an explosive atmosphere. Explosive gases can be present around batteries. A properly vented battery environment is considered safe, but it is the responsibility of M 6 AVTM246100B Rev B June 2003 the user to verify conditions prior to using the Battery Ground Fault Tracer. ? Wear protective clothing and eye protection to guard against skin and eye damage from battery acid. ? Ensure that test leads and probes are in good condition, clean and free of broken or cracked insulation. Observe the following cautions marked on the transmitter panel. 1. For use on ungrounded systems only. 2. Set power switch to off prior to connecting or disconnecting output leads to battery. 3. Connect output leads to J3 before connecting to battery system. 4. Ensure output ground connection is made to system earth ground. 5. Adhere to all industry standards for testing battery systems. This instrument is only to be used by suitably trained personnel who are familiar with the hazards involved in testing high-voltage dc systems. G G CAUTION Refer fuse replacement to qualified service personnel only. To prevent electric shock and fire hazard, use only the fuse specified in the parts list which is identical in respect to type, voltage rating, and current rating. Connection to Power Source The power input plug must be inserted only into a mating receptacle with a ground contact. Do not bypass the grounding connection. Any interruption of the grounding connection can create an electric shock hazard. Make sure that the receptacle is properly wired before inserting the plug. The test set is supplied with a brown, blue and green/yellow supply cord, the brown cord lead must be connected to the live pole and the white or blue cord lead must be connected to the neutral