CUSTOMER REQUIREMENTS AT POWER SUBSTATIONS

Transcription

1 CUSTOMER REQUIREMENTS AT POWER SUBSTATIONS Customer Handout Date Aug 2, 2010 Version 1.0 File Name Customer Requirements At Power Substations Document Id Outside Plant Engineering 1

2 Table Of Contents 1.0 GENERAL OBJECTIVES SCOPE PERIODIC INSPECTIONS STANDARDS SERVICE PROVISIONING OPTIONS SERVICE PERFORMANCE OBJECTIVES (SPO) SERVICE TYPES TARIFFS LOCATION OF THE DEMARCATION POINT PROVISIONING OPTIONS EXISTING LOCATIONS CUSTOMER REQUIREMENTS IN THE POWER STATION TECHNICAL DATA LIST OF ACRONYMS

3 1.0 GENERAL 1.1 OBJECTIVES As a service provider, FairPoint, working with customer-provided technical data, is responsible for determining requirements for proper methods of protection to achieve industry electrical protection standards while providing customer-specified service performance objectives. Protection at power stations is necessary to: 1.2 SCOPE i) ensure the safety of personnel either using or working on the telecommunications facilities. ii) minimize damage to equipment and facilities. iii) provide the degree of service integrity and reliability requested by the power utility. NOTE: FairPoint reserves the right to suspend or deny all service without adequate High Voltage Protection until adequate protection is provided. This document is applicable to: i) Telecommunication cables with metallic members providing service to power stations, generating plants, and windmill generating plants. ii) All types of service into a power station including POTS (Plain Old Telephone Service i.e. dial tone), coin telephones, special service circuits and private line services. NOTE: This document is not applicable when fully dielectric fiber optic cables are used into the high voltage locations. 1.3 PERIODIC INSPECTIONS Periodic inspections by representatives of FairPoint and the power utility are useful in determining if the protection measures are still effective. The inspections will verify that the high voltage protector is still wired properly, that no connections are loose or faulty and that the grounding scheme has not been defeated. These inspections will ensure that safety is not compromised. Bonding and grounding procedures are requirements to ensure the effectiveness of the protection equipment. Inspections should also be conducted during additions, rearrangements, repair and any other maintenance activity. FairPoint employees must contact the power company s representatives before performing any work inside the power station or its surrounding facilities. 3

4 1.4 STANDARDS FairPoint procedures are in agreement with the following IEEE Standards: a) IEEE Recommended Practice for the Protection of Wire-Line Communication Facilities Serving Electric Supply Locations. b) IEEE Recommended Practice for the Electrical Protection of Optical Fiber Communication Facilities Serving, or Connected to, Electrical Supply Locations. 4

5 2.0 SERVICE PROVISIONING OPTIONS Selecting a service option involves determining two conditions before initiating a service request. These conditions are the Service Performance Objectives (SPO) and the Service types. The customer must determine the service options needed / wanted when requesting telecommunication services to a power station location. Before a protection scheme for the telecommunications service is selected, the customer must identify the importance of the service requested. 2.1 SERVICE PERFORMANCE OBJECTIVES (SPO) Interruptions or outages of telecommunication circuits due to the effects of power system faults can be minimized through the use of High Voltage Protection (HVP) equipment. Because of the customers need for service continuity during power system faults on some types of telecommunications services provided to power stations, Service Performance Objectives (SPO) have been established for the purpose of permitting the customer to specify the performance objectives for the services provided to power stations. The SPOs are related to service interruptions or outages due to the effects of power system faults. The three categories of SPO, as defined in IEEE Standard 487, are: Class A. A non-interruptible service performance that operates before, during, and after a power fault condition. Class A requires special design and circuit coordination between the Power Company and. Class B. An interruptible service performance that is self-restoring and must operate before and after a power fault condition, but not necessarily during a power fault condition. Class B requires special design and circuit coordination between and the power company. Class C. An interruptible service performance that can tolerate a station visit to restore service. NOTE: If a Class A or B service is required at a particular substation location, then Class C cannot be ordered. Therefore, all services must be coordinated according to the highest SPO class. The above SPO classifications are used only to indicate the customer s desired telecommunications service performance at times of power system faults Class A Class A is the most demanding type. It is service performance that cannot tolerate even a momentary service interruption before, during, or after a power system fault. The nontolerable service interruptions include both loss of dependability (failure to deliver a valid trip or control signal) and loss of security (delivery of a false trip or control signal). 5

6 To fully achieve SPO Class A the use of dual alternate routing should be considered. This means that critical operating circuits are duplicated, end-to-end, over two geographically separated routes so that an interruption on one route will not result in an interruption on the other. Special Construction Charges for alternate routing may apply. Examples of Class A circuits would be pilot-wire protective relaying, audio-tone protective relaying, and critical supervisory circuits that are used for remote control of a power network. The use of some digital services / equipment, such as HDSL, to provide Class A is not recommended due to synchronization issues that may preclude the circuit to operate before, during and after the fault Class B Class B is less demanding than Class A in that a service interruption can be tolerated for the duration of a power system fault but service continuity must be restored immediately after the fault without requiring any repair personnel activity. Examples of Class B services are emergency telephone, high priority data collection, supervisory control, and signal and alarm circuits that would be required to put a power network back into operation after a power fault Class C Class C is the least demanding in that an interruption or a service outage due to a power fault that requires a station visit to restore service can be tolerated. Examples of Class C services are POTS, non-critical telemetering and data, and some signal and alarm circuits that would not be used for network restoration. 6

7 2.2 SERVICE TYPES The requirements of the most common telecommunications circuits used by power utilities have been classified into the following major types: Type 1A: Service requiring either DC transmission or AC and DC transmission and used for basic exchange telephone service (POTS) or private-line and/or voice telephone service. Service Type 1A can have an SPO of B or C. Type 1B: Type 2: Type 3: Type 4: 2.3 TARIFFS Service requiring either dc transmission or AC and DC transmission and used for teletypewriter, telemetering, and noncritical supervisory control. All circuits are used for talking plus DC telemetering and telegraph. Service Type 1B can have an SPO of B or C. Is a private line service requiring AC or DC transmission (or both) used for pilot wire protective relaying or DC tripping. Type 2 is normally a metallic cable pair placed end-to-end, but it can be a DC telegraph channel. Service Type 2 is always an SPO of B. Is a private-line service requiring AC-only transmission used for telemetering, supervisory control, and data. Type 3 uses all tone signals (300 Hz to 5 MHz) and High Capacity Digital services. Service Type 3 can have an SPO of A or B. A private-line service requiring AC-only transmission used for audio tone protective relaying. Service Type 4 is always an SPO of A. The use of High Voltage Protection (HVP) equipment in the provisioning of service to Power Company locations is regulated by State Tariffs in most locations. When the customer selects to own the HVP equipment and there is no approved tariff, charges will be determined by using the Individual Case Basis (ICB) process. NOTE: reserves the right to suspend any service without adequate HVP until such protection is provided. 2.4 LOCATION OF THE DEMARCATION POINT The preferred location for terminating cable facilities and equipment is in the terminal room (or the telecommunication room) of each substation or HV location. A hut or cabinet located just outside the substation fence line (closer to the service entrance point) is also acceptable for cases when inadequate terminal space exists in the terminal room. 7

8 NOTE: Additional special grounding requirements are needed when the HV protector is located at the station fence line. (The station ground grid must be extended toward the cabinet. This is required for personnel safety purposes). The demarcation point (DP) is established on the customer side of the HVP at a termination block or loop-back device (i.e. smart-jack). CAUTION: Under NO circumstances is the demarcation point to be located between the station fence line (edge of the station grounding mat) and the edge of the Zone of Influence (ZOI). It is the responsibility of the customer to transport the service beyond the DP to the desired location. established hand-off is at the DP. Special Construction Charges may be applicable. These charges will be applied in accordance with the appropriate Tariff or through the ICB / Special Assembly Process. 2.5 PROVISIONING OPTIONS The two (2) options available for HVP provisioning are: 1. owns the HVP equipment. This option requires FairPoint to design, install, and maintain the HVP devices. 2. The power utility owns and maintains the HVP. This option requires the power utility to design, install, and maintain the HVP devices. This option must be supported by applicable Tariffs. The customer is responsible for equipment damage and service interruptions arising from the failure of the high voltage protector owned by them. NOTE: When the power utility chooses to furnish the HVP, this equipment must meet the technical requirements specified in the latest available issue of IEEE Standard 487. reserves the right to suspend any service without adequate HVP until such protection is provided. 2.6 EXISTING LOCATIONS Existing sites will be addressed as additional circuits or service is requested. Service activity at existing locations will initiate the communication process between FairPoint Communications and the customer and will act as the catalyst to begin the upgrade process. 8

9 3.0 CUSTOMER REQUIREMENTS 3.1 IN THE POWER STATION The following items should be provided by the power utility when the HVP equipment is to be located inside the power station: a) A plywood backboard (3/4 inch / 19 mm thick minimum) for mounting the HVP and the associated equipment. b) Adequate local power (24, 48 or 130 Volts DC, 115 Volts AC). A #6 AWG solid copper insulated ground conductor. The wire must extend no more than 20 feet (6 m) from the HVP equipment backboard to the power station ground connection point. This grounding conductor must be free of sharp bends. Any required bends must have at least 12 inches (305 mm) radius corners. Schedule 80 PVC conduit (suitable for cable pulling) from the HVP location to a point 10 feet (3 m) beyond the substation fence or ground grid. 3.2 TECHNICAL DATA The Power Company should provide the following (8) items of information on either the Power Company s letterhead or the Power Station Request for Telecommunications Service Form (see Exhibit 1 titled Power Station Data on page 12). 1. Power Station Name & Location (Address) 2. Ground Mat / Grid Size (or Area) Sq. Ft. This is the area of the station ground grid. 3. Total Expected Fault Current (Line To Ground) A rms Fault current is the total current produced by the fault. The fault current returns to the power station through metallic paths, such as overhead ground wires, neutrals, etc, and the earth. 4. Power Station Ground Impedance The Power station impedance to remote earth includes the contribution of the ground grid and all other lines that connect to the power station. This value is used in calculating Ground Potential Rise (GPR). Specify if measured or calculated. 5. Power Station X/R The X/R ratio gives an indication of the time required for the DC transient to decay and of the volt-time area contributed by the transient term. 9

10 6. Earth Return Current A rms Earth return current is the portion of the fault current (% earth return) that returns to the power station through the earth. Earth return current is the current that causes GPR, since this is the current that flows through the power station grounding impedance. 7. Earth Resistivity Ohm-meters This is the electrical property of the earth at the site given in either the "Uniform" type or the "Two- Layer" model format. Specify if measured or calculated. 8. Remote Earth Point The calculated distance to the 300-volt point. NOTE: A Licensed Engineer (P.E.) should sign Data provided by the Power Company. The data should be on Power Company letterhead if FairPoint Communication s forms are not used. 10

11 4.0 LIST OF ACRONYMS AWG Average Weight Gauge DP Demarcation Point GPR Ground Potential Rise HDSL High bit rate Digital Subscriber Line HV High Voltage HVP High Voltage Protection ICB Individual Case Basis IEEE Institute of Electrical and Electronics Engineers POTS Plain Old Telephone Service SPO Service Performance Objectives ZOI Zone of Influence 11

12 Table 1 Exhibit 1 POWER STATION DATA Power Station Name/Address GROUND MAT / GRID SIZE(SQUARE FOOT AREA) TOTAL EXPECTED FAULT CURRENT(line-to-ground)Specify Amps rms or Amps peak: GRID IMPEDANCE to Remote Earth(in ohms): Specify Measured or calculated X/R Ratio: Earth Return Current(% earth return)in Amps Peak Ground Potential Rise: Remote Earth Point(300 V) Distance from Substation Grid: Fairpoint Contact: NAME: ADDRESS: TELEPHONE: FACSIMILE: Power Company Contact: NAME: ADDRESS: TELEPHONE: FACSIMILE: Signature: Date: 12