Transcript
S&C BankGuard Plus® Controls
For Substation Capacitor Banks and Shunt Reactors
Specifications Conditions of Sale STANDARD: Seller’s standard conditions of sale set forth in Price Sheet 150 apply, except as modified by the “SPE CIAL WARRANTY PROVISIONS,” and “WARRANTY QUAL IFICATIONS” sections in this specification bulletin.
SPECIAL TO THIS PRODUCT: INCLUSIONS: The S&C BankGuard Plus Control protects substation shunt capacitor banks from overvoltage stress and pro vides turn-to-turn winding fault protection for shunt reac tors. The BankGuard Plus has the sensitivity to detect and alarm on the loss of individual capacitor units or develop ing winding faults. With the capability to detect and alarm upon the loss of the first failed capacitor unit in a bank, the BankGuard Plus offers users a major advantage: The failed unit can be replaced at a convenient, planned time. . . not on an urgent basis, after subsequent capacitor units have failed and the bank has been locked out. An adjustable time delay is uti lized to avoid false alarms due to transient disturbances. Nuisance alarms and lockouts due to the induction of high voltages during routine bank de-energi zation are also eliminated. The BankGuard Plus can detect—and compensate for—system voltage and capacitor-bank or reactor unbal ance resulting from manufacturing-tolerance variations among the individual capacitor units and reactor phase windings.f In large-size capacitor banks, such unbalance voltages can introduce significant errors in, or even over power, the voltage signal created by the loss of individual capacitor units. The BankGuard Plus includes filtering to attenuate spurious transients and harmonics. The BankGuard Plus further includes gross-overvoltage logic which bypasses the lockout-level and timing-control logic to achieve fast capacitor-bank or reactor isolation in the event of a flashover of a series group in the bank or flashover of a significant portion of a phase winding. The BankGuard Plus is suitable for standard 19-inch relay rack mounting. An optional bezel is available for flush mounting in a switchboard or control console. The BankGuard Plus is a direct replacement for S&C Auto matic Control Devices—Types UP, GP, and UPR. Terminal strip connections are identical with those of the Type UP and all connections for Types GP and UPR are accommo dated.
October 29, 2012© S&C Electric Company
Protection of Ungrounded, Wye-Connected Shunt Capacitor Banks, Including Double-Wye Banksl In these applications, the BankGuard Plus monitors the voltage between the neutral (common) connection of the capacitor bank and ground with a 15-volt-ampere S&C Potential Device. As successive individual capacitor units in a series group of the bank are isolated by their respective fuses, the surviving capacitor units in the group are protected against cascading voltage overstress by the BankGuard Plus, which isolates and locks out the entire bank when a predetermined neutral-to-ground voltage value is exceeded. Protection of Grounded, Wye-Connected Shunt Capacitor Banks Consisting of Two or More Series Groups per Phase In these applications, the BankGuard Plus monitors, for each phase of the capacitor bank, the voltage between an intermediate tap point and ground with a 30-volt-ampere S&C Potential Device. As successive individual capacitor units in a series group of the bank are isolated by their respective fuses, the surviving capacitor units in the group are protected against cascading voltage overstress by the BankGuard Plus, which isolates and locks out the entire bank when a predetermined tap point-to-ground voltage value is exceeded. Protection of Ungrounded, Wye-Connected Shunt Reactorsl In these applications, the BankGuard Plus monitors the voltage between the neutral (common) connection of the reactor and ground with a 15-volt-ampere S&C Potential Device. If a turn-to-turn fault develops in a phase winding, the BankGuard Plus isolates and locks out the entire reactor when a predetermined neutral-to-ground voltage value is exceeded. f For proper unbalance compensation, the system-derived voltages monitored by the BankGuard Plus must be obtained by means of 30-volt-ampere S&C Potential Devices—or voltage transformers—con nected to the segment of station bus to which the capacitor bank or reactor is tapped. Connecting circuits from the potential devices or voltage transformers to the BankGuard Plus must be free of variable loads, variable voltage drops, and ground loops so that the voltages monitored accurately represent the magnitude and phase angle of the bus voltages.
l For applications where the source is a delta-connected tertiary trans former winding, a grounded-wye broken-delta voltage-transformer “bank” with shunt resistor—referred to as a high-impedance grounding trans former (normally required for ground-fault detection)—is required to maintain the stability of phase-to-ground voltage relationships for all but fault conditions. Otherwise spurious signal voltages could appear at the neutral of, and result in isolation of, the capacitor bank or reactor. The BankGuard Plus includes an unbalance compensation function that detects and compensates for up to 10% error voltage appearing between the neutral and ground.
Specification Bulletin 1011-31
S&C BankGuard Plus® Controls Conditions of Sale —Continued SPECIFICATION NOTES: S&C BankGuard Plus Con trols have been tested to verify their capability to with stand, without misoperation or damage, surge-voltage tests as follows: 1. The ANSI Surge Withstand Capability Test (ANSI Stan dard C37.90a, 1974). The specified surges are applied at all control device terminals. 2. A 5-kV, 3.75-joule capacitive-discharge test with surge applied at all control device terminals. This additional test represents a surge level well in excess of those nor mally encountered in control wiring in utility envi ronments. To prevent damage to the control device in the event that surges which exceed factory-tested levels are encoun tered, S&C’s control-circuit fusing recommendations must be followed. The required fuse blocks and fuses are fur nished with the control devices. If frequent surges in excess of factory-tested levels are anticipated, S&C should be advised as to the severity of the surges so that special recommendations can be made. For all grounded-wye capacitor-bank installations the following steps must be taken to ensure that the control device is not subjected to surges in excess of the level defined in ANSI Standard C37.90a: 1. Adequate shielding must be provided for control-circuit wiring. 2. For installations involving two or more grounded-wye capacitor banks in the same station, their neutrals must be interconnected and grounded at a single point only. Additionally, it is recommended (although not required) that the capacitor-bank switching devices be equipped with pre-insertion impedances for reduction of inrush current and transient voltage disturbances associated with capacitor-switching applications. EXCLUSIONS: BankGuard Plus Controls do not include voltage-monitoring devices. Refer to Specification Bulletin 581-31 for information on S&C Potential Devices. SPECIFICATION DEVIATIONS: Refer to “Options” table on page 4. SPECIAL WARRANTY PROVISIONS: The standard warranty contained in seller’s standard conditions of sale, as set forth in Price Sheet 150, applies to BankGuard Plus Controls, except that the first paragraph of said warranty is replaced by the following:
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(1) General: Seller warrants to immediate purchaser or end user for a period of 10 years from the date of ship ment that the equipment delivered will be of the kind and quality specified in the contract description and will be free of defects of workmanship and material. Should any failure to conform to this warranty appear under proper and normal use within ten years after the date of shipment the seller agrees, upon prompt notification thereof and confirmation that the equip ment has been stored, installed, operated, inspected, and maintained in accordance with recommendations of the seller and standard industry practice, to correct the nonconformity either by repairing any damaged or defective parts of the equipment or (at seller’s option) by shipment of necessary replacement parts. The seller’s warranty does not apply to any equipment that has been disassembled, repaired, or altered by anyone other than the seller. This limited warranty is granted only to the immediate purchaser or, if the equipment is purchased by a third party for installation in third-party equipment, the end user of the equipment. The seller’s duty to perform under any warranty may be delayed, at the seller’s sole option, until the seller has been paid in full for all goods purchased by the immediate purchaser. No such delay shall extend the warranty period. Replacement parts provided by seller or repairs per formed by seller under the warranty for the original equipment will be covered by the above special war ranty provision for its duration. Replacement parts purchased separately will be covered by the above special warranty provision. WARRANTY QUALIFICATIONS: Warranty of Bank Guard Plus Controls is contingent upon the installation, configuration, and use of the control or software in accor dance with S&C’s applicable instruction sheets. This war ranty does not apply to major components not of S&C manufacture, such as batteries, communication devices, and remote terminal units. However, S&C will assign to immediate purchaser or end user all manufacturers’ war ranties that apply to such major components. END USER LICENSE AGREEMENT: End user is granted a nontransferable, non-sublicensable, nonexclu sive license to use the IntelliLink® Remote Setup Software and/or other Software furnished with S&C BankGuard Plus® Controls only upon acceptance of all the terms and conditions of the seller’s end user license agreement set forth in Price Sheet 155.
S&C BankGuard Plus® Controls How to Order 1. Control a. Select the catalog number of the desired control from the table on page 4. b. Add Suffix “-B” to the catalog number if the optional bezel is desired. See the “Options” table on page 4. c. For calibration purposes, include information on the neutral-, tap-, and/or system-voltage sensing devices used, i.e., catalog number of S&C Potential Device(s), or primary voltage rating and turns ratio of voltage transformer(s) Plus nominal voltage of voltage-trans former secondary circuit.m
2. Example For an S&C BankGuard Plus Control for application on an ungrounded capacitor bank connected to a system rated 138 kV nominal, specify: “Catalog Number 238062, for use with one S&C 15-volt-ampere S&C Potential Device, Catalog Number 81576R1, and, for unbalance compensation, three 30-volt-ampere S&C Potential Devices, Catalog Number 81349R6-T (or three voltage transformers with a primary rating of 80,500 volts, turns ratio of 1200:1, and secondary circuit rated 67.08 volts), for application on a system rated 138 kV nominal.” m If no information on the neutral-, tap-, and/or system-voltage sensing devices is specified, the device will be shipped marked “for field calibration.”
S&C Specification Bulletin 1011-31 3
S&C BankGuard Plus® Controls Bankguard Plus Controls Diagram
Control ControlSource Voltage
Application1 Switch Operator
For protection of ungrounded, wyeconnected and double-wye-connected shunt capacitor banks2
Optional sensing for unbalance compensation function
For protection of grounded, wyeconnected shunt capacitor banks
Optional sensing for unbalance compensation function
For protection of ungrounded, wyeconnected shunt reactors2
Optional sensing for unbalance compensation function
2 For applications where the source is a delta-connected tertiary trans former winding, a grounded-wye broken-delta voltage-transformer “bank” with shunt resistor—referred to as a high-impedance grounding trans former (normally required for ground-fault detection)—is required to maintain the stability of phase-to-ground voltage relationships for all but fault conditions. Otherwise spurious signal voltages could appear at the neutral of, and result in isolation of, the capacitor bank or reactor. S&C BankGuard Plus Controls include an unbalance compensation function that detects and compensates for up to 10% error voltage appearing between the neutral and ground. n S&C Potential Device rated 15 volt-amperes having a system voltage rating as follows: below 23
23
34.5
46
69
23
23
23
23
34.5
115 138 161 230 69
48 to 250 Vdc or 120 to 240 Vac, 50 or 60 Hz
238062
5
11 (4.95)
nearest S&C Sales Office.
S&C Potential Device System Voltage Rating, kV, Nom.
Page Reference for Net Wt., Dimensional Lbs. (Kg.) Information
1 For installations in the vicinity of 345-kV or 500-kV circuits, refer to the
Nominal Source Voltage, kV
BankGuard Plus Control
Potential Device
Catalog Number
69
138 138
The 15-VA Potential Device is recommended. If a 30-VA Potential Device is used for neutral-to-ground sensing it must either be equipped with factory-adjusted calibration device, Catalog Number Suffix “-T,” or a locally installed 480-ohm, 50-watt resistor may be used to terminate the secondary output of the 30-VA Potential Device.
l S&C Potential Device rated 30 volt-amperes equipped with factoryadjusted calibration device, Catalog Number Suffix “-T.” The minimum
system voltage rating of the potential device is derived by calculating the voltage appearing between the intermediate tap points and ground and multiplying this value by 3. Since S&C Potential Devices are not of instrument-class accuracy, their performance in intermediate-tap-point voltage-monitoring applications on very-large-sized grounded, wye-connected shunt capacitor banks may not be entirely satisfactory, especially if it is desired to obtain an alarm signal upon the loss of a single capacitor unit. Specifically, this alarm sig nal setting on banks consisting of more than 150 capacitor units or more than 5 series groups per phase (often the case where system voltage is higher than 138 kV) may possibly lead to nuisance alarms under severe rainfall conditions. In cases where such false operations are of especial concern, higher-accuracy devices such as voltage transformers or capaci tor-coupled voltage transformers are recommended. The minimum sys tem voltage rating of these devices is derived by calculating the voltage appearing between the intermediate tap points and ground and multiply ing this value by 3. Adequate damping resistance must be connected across each voltage-transformer secondary circuit; viz., a resistance load equal to at least 2% of the transformer thermal rating. w S&C Potential Device rated 30 volt-amperes (or voltage transformer) having a system voltage rating equal to the voltage of the system to which the capacitor bank or reactor is connected. If capacitor-unit or reactor phase-winding manufacturing tolerance variations are of specific concern, a single potential device or voltage transformer is required. If system voltage unbalance is also of concern in ungrounded capacitor bank or reactor applications, three potential devices or voltage transformers are required.
Options Item
Mounting Bezel for Flush Mounting of BankGuard Plus Control, 220 W 80 H Z\v0 D
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Suffix to be Added to Control Catalog Number
-B
S&C BankGuard Plus® Controls BankGuard Plus Dimensions in inches (mm) 17.13 (435)
14.68 (372.9)
5.25 (133.4)
13.97 (354.8)
19.00 (482.6) 18.13 (460.5) 1.50 (38.1) 5.25 (133.4)
2.25 (57.2)
UNBALANCE COMPENSATION
LOCKOUT LEVEL
PUSH TO SET
PUSH TO READ
4.97 (126.2) PUSH TO RESET
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