Single-Phase Meter Installation

Transcription

1 Single-Phase Meter Installation S T U D E N T M A N U A L March 31, 2005

2 2 STUDENT TRAINING MANUAL Prerequisites: None Objectives: From memory, you will be able to explain single-phase meter test procedures, calculate consumption costs, as well as perform pre and post meter installation checks. Rationale: The installation of a meter to the customer is the last phase in the construction process. It is important to do this correctly so proper metering is provided to the customer and accurate consumption and billing is provided to the utility. Learning Objectives Describe the application and permit requirements for meter installations. Explain the pre-installation checks required for single-phase meters. Explain the post-installation checks required for single-phase meters. Calculate the consumption and demand costs of a single-phase meter. Demonstrate the procedure used to perform an accuracy test. Explain the procedure used to process a dispute test. Learning Methods Self-learning + On-the-job Self-learning + On-the-job Self-learning + On-the-job Self-learning + On-the-job On-the-Job Demonstration and Practice Self-learning + On-the-job EVALUATION METHODS Written test Written test

3 SINGLE-PHASE METER INSTALLATION 3 Written test Written test On-the-Job Evaluation Written test STUDENT RESOURCES Learning Steps Electric Service Guide Revenue Metering Connection Diagrams 1. Read the Learning Guide. 2. Follow the steps outlined in the Learning Guide. 3. Clarify any questions or concerns you may have. 4. Complete the Practice and Feedback.

4 4 STUDENT TRAINING MANUAL Lesson 1: Application and Permit Requirements for Meter Installations Learning Objective:Describe the application and permit requirements for meter installations. Learning Method:Self-learning + On-the-job Evaluation Method:Written test Application for Service Permits The application for service should be made at the local utility office and should include the following information: Type of service Overhead or underground Single-phase and/or three-phase Supply voltage preferred Site plan, including location of service entrance Date the service is required Connected load and anticipated demand, both single-phase and three-phase Motor schedule Switch gear requirements Special load characteristics - voltage sensitive, motor starting characteristics, computer operations, etc. Applications involving customer owned substations and non-utility generators require additional information as outlined in the Electric Service Guide Any work being completed on a service requires a form. This ensures safety to the home owner, the electrical contractor, and, of course, the utility. There are three forms and a disconnection order which must be considered: Electrical Permit (previously Form J) Form K Form G Electric Service Disconnection Order

5 SINGLE-PHASE METER INSTALLATION 5 Electrical Permit An Electrical Permit is issued by the SaskPower inspection division to electrical contractors or others responsible for permanent or temporary wiring installations, alterations, repair or extensions. Conversions of farm yard distribution from overhead to underground are included. This permit is also required for reconnection of services that have been disconnected for more than one year or disconnected due to fire or flood. This form is an authorization for the utility to provide service to a customer and ensures an inspection of the installation by the SaskPower inspection division. A copy of the Electrical Permit must be sent to the local SaskPower office. The service will be connected once a copy of the Electrical Permit is received from the licensed contractor with the appropriate fees paid. The service must meet proper grounding practices and clearance standards, and must be deemed free of short circuits and other defects.! CAUTION The main switch is to be left open on services requiring connection. An Electrical Permit is required prior to the connection of a temporary service. A separate or additional Electrical Permit is required when transferring the service from temporary to permanent. This form states that everything is intact and the service is ready to be energized. ---Note--- Temporary services must be disconnected after the permanent service is connected. Form K Form G A Form K is a written notice issued by the electrical inspector informing the electrical contractor to make changes to a new service in order to comply with the electrical code. A Form G is a written notice issued by the electrical inspector informing

6 6 STUDENT TRAINING MANUAL the electrical contractor to make changes to an existing service in order to comply with the electrical code. Electric Service Disconnection Order When orders to correct defects or hazards are not complied with, the chief electrical inspector can issue an electrical service disconnection order to cut off the service on a specific date. The utility will disconnect the service on the date specified unless arrangements have been made with the electrical inspection division. Reconnection of the service is made only with the consent of, or instructions from, the chief electrical inspector. All appropriate paper work must be in place.

7 SINGLE-PHASE METER INSTALLATION 7 Lesson 2: Pre-Installation Checks for Single- Phase Meters Learning Objective:Explain the pre-installation checks required for single-phase meters. Learning Method:Self-learning + On-the-job Evaluation Method:Written test Introduction Prior to installing a meter at a new service location, be aware of the following: Final meter height from the finished grade is to be 1.7m Type of meter required (A-base meter, socket meter, demand meter) Measurements Canada seal is intact on the meter (if the seal is broken, the meter must not be used) Secure mounting of the meter socket Electrical Permit in possession Live incoming wires are connected to the line side terminals of the meter socket and customer wires are connected to the load side terminals of the meter socket Loose connections on the line and load side terminals Proper ground connections in the meter socket and at the external ground rod Reference For further information, refer to the Construction Standards manual or the Electric Service Guide.

8 8 STUDENT TRAINING MANUAL Lesson 3: Post-Installation Checks for Single- Phase Meters Learning Objective:Explain the post-installation checks required for single-phase meters. Learning Method:Self-learning + On-the-job Evaluation Method:Written test Introduction Disc Rotation Once a meter is installed, there are three precautionary checks to complete: Disc rotation Light load starting Meter creep Ensure the disc turns in the same direction as the arrow indicates. A reversed rotation indicates the line and load leads in the meter socket are reversed. Light Load Starting A meter that is working properly should start rotating with as little as 15 watts connected to it. To check this, disconnect the service load and connect a 15 watt bulb to the load side of the meter, first on one side of the circuit, then on the other.! CAUTION Ensure that only 120V is provided to the light. Do not hook it up phase-to-phase.

9 SINGLE-PHASE METER INSTALLATION 9 Meter Creep ---Note--- If the meter is to be used, it must start rotating at this point. Meter creep is when a meter turns under no-load conditions. A kwh meter is said to be creeping when the disc makes more than one complete revolution after the load has been removed. ---Note--- If creeping occurs, it is usually in a forward motion and can be mistaken for light load. The following steps should be followed if a meter is suspected of creeping: Turn the main breaker to the Off position or disconnect the load wires from the terminals. If the creeping stops, it is assumed there is a wiring defect in the customer s load. Notify the customer. If the creeping continues, the meter is defective and should be changed immediately. The meter should be sent to the meter repair shop and clearly marked creeping meter. Causes of Meter Creep Incorrect meter adjustment Vibration Supply voltage is too high Magnets (brakes) in the meter are out of line Short circuit in current coils Current leakage in the customer s wiring Stray magnetic forces

10 10 STUDENT TRAINING MANUAL Lesson 4: Consumption and Demand Costs Learning Objective:Calculate the consumption and demand costs of a single-phase meter. Learning Method:Self-learning + On-the-job Evaluation Method:Written test Introduction The amount of energy used, in turn, becomes a cost to the customer. In order to charge the correct amount, we need to know how to read a meter correctly for kilowatt-hour consumption. How to Read a Meter There are four or five dials which are read to get the kilowatt-hour consumption of the period. A meter is read in the following way: Extreme right-hand dial measures the single units Second dial from the right measures the tens (10s) Third dial from the right measures the hundreds (100s) Fourth dial from the right measures the thousands (1000s)

11 SINGLE-PHASE METER INSTALLATION 11 Fifth dial, if any, would read ten thousands (10,000s) ---Note--- There is also a test dial on the meter which is for test purposes only. Cost of Consumption Using the previous diagram, we can calculate the amount of energy the customer has used since the meter was last read, and by multiplying the cost per kwh, we can determine the amount the customer will be charged. Example: The previous read was By the diagram, we can see that this read is The total amount of energy used is: 7250kWh kWh = 2568kWh If the energy rate is 5.85 cents per kwh, we can determine the cost of consumption. Cost = 2568kWh x 5.85 cents/kwh Cost = cents divided by 100 Cost = $ Therefore, a sum of $ would be applied to this customer s next bill to cover their consumption.

12 12 STUDENT TRAINING MANUAL Rates for Metered Customers Reference There are a number of different rates for energy costs, depending on the type of customer. For further information on rates, refer to the Rates and Policies manual. Demand Energy Meters A demand energy meter is in actual fact, two meters in one body. It is a kilowatt-hour or watt-hour meter which measures energy and a demand meter which measures kva. The demand portion of the meter measures and registers the load on the service installation at any given time. This is necessary to determine what kind of load the customer is inflicting upon the apparatus. For example, if a customer normally draws a load of 50kVA, but requires 200kVA for one hour per day, we have no choice but to supply

13 SINGLE-PHASE METER INSTALLATION 13 Billing Multiplier him with a 200kVA service. To pay for this extra service, the customer is billed an extra amount based on the demand reading of the meter. The demand portion of the meter is constructed so that a pointer advances along a scale to record the present kva demand. A second pointer is integrated into the meter and performs the same function as that of the first pointer. However, the maximum value reached will be retained, and can only be reset by the proper authorities (meter reader, district operator). The maximum value recorded by the demand needle is the value in which the customer is billed. The demand reading is multiplied by the billing multiplier to calculate the total demand. This demand can then be multiplied by the cost per kva. Example: A customer has a demand reading of 800VA on the meter and the billing multiplier for the service is 80. Calculate the demand charge if the customer must pay $13.01 per kva on consumption above 50kVA. Total Demand = Read x Billing Multiplier Total Demand = 800 x 80 Total Demand = 64,000VA or 64kVA Cost = (64-50) x $13.01 Cost = 14 x $13.01 Cost = $ Note--- When reading meters, never forget to reset the demand or peak demand needle as the customer may not reach that maximum level during the next billing period.

14 14 STUDENT TRAINING MANUAL Meter Accuracy In many instances, a customer may believe the meter to be faulty or inaccurate, usually due to high electrical bills. The customer may possibly have a reason for concern; however, most times the problem does not lie with the accuracy of the meter. The following are some possible reasons for high meter readings: Customer load may have increased Faulty equipment such as electric water heaters may draw abnormally high amperages Errors in the meter reading Present reading was read too high Previous reading was read too low If you cannot satisfy the customer as to the explanation of a high power bill, they have the option of disputing the meter through an accuracy test or dispute test. ---Note--- The standards division requires that all meters be calibrated to ensure that an error in registration does not exceed +/- 2% or +/- 1% for electronic meters. A meter involved in a customer initiated dispute must be within +/- 3%. Meters sent to the meter repair shop are tested to an accuracy of +/-.5%. Accuracy Test An accuracy test can be done on site to check the accuracy of a singlephase meter. By performing this test, there is a good possibility of reassuring the customer that the meter is correct and avoiding a dispute test.

15 SINGLE-PHASE METER INSTALLATION 15 Load Check Perform a load check on the service being metered. Calculate the metered load. Check the kh factor of the meter. Simultaneously start counting time (in seconds) and the number of disc revolutions.! CAUTION To ensure consistent accuracy, there must be a minimum of ten disc revolutions over a period of at least 90 seconds (minimum time). Calculate the load recorded on the meter. Meter Accuracy The above calculation will indicate the meter accuracy in percent. A positive number indicates an error in favor of the utility and a negative number indicates an error in favor of the customer. If the meter accuracy test fails to convince the customer that there is not a problem with the meter, the meter can be put through a government dispute test.

16 16 STUDENT TRAINING MANUAL Lesson 5: Perform an Accuracy Test Learning Objective:Demonstrate the procedure used to perform an accuracy test. Learning Method:On-the-Job Demonstration and Practice Evaluation Method:On-the-Job Evaluation

17 SINGLE-PHASE METER INSTALLATION 17 Skills Practice 1. Demonstrate the procedure used to perform an accuracy test. 0. Check all wiring and connections. 0. Ensure the load is constant and purely resistive. 1. Check and record the voltage. 2. Check and record the amps on both legs. 3. Start timing and counting simultaneously. 4. Record the number of disk revolutions (minimum of 10). 5. Record the number of seconds (minimum of 90). 6. Record the kilowatt-hour value. 7. kva calculations completed correctly. 8. kw calculations completed correctly. 9. Accuracy calculations completed correctly.

18 18 STUDENT TRAINING MANUAL Lesson 6: Dispute Test Procedure Learning Objective:Explain the procedure used to process a dispute test. Learning Method:Self-learning + On-the-job Evaluation Method:Written test Introduction If a customer requests a dispute test, collect the specified fee. In the event that the meter fails the dispute test, the fee will be returned, as well as any money resulting from the billing adjustment due to the faulty meter. If the meter tests within + or - 3%, SaskPower keeps the fee as payment for the test. Proceed to change the meter and fill out the necessary paper work. Tag the meter accordingly (dispute test meter) and mail the meter to the meter repair shop. After the dispute meter is received at the meter shop, it is sent to Measurements Canada to be tested. This is a federal government department. Once the meter is tested, the results are sent with one copy going to the metering department and one copy to the customer. The metering department will send a copy to the region office and customer accounts for billing adjustments.

19 SINGLE-PHASE METER INSTALLATION 19 Summary To summarize this module, you have learned: The application and permit requirements for meter installations. The pre-installation checks required for single-phase meters. The post-installation checks required for single-phase meters. To calculate the consumption and demand costs of a single-phase meter. To perform an accuracy test. To process a dispute test. Practice Feedback Review the lesson, ask any questions and complete the self-test. Evaluation When you are ready, complete the final test. You are expected to achieve 100%.

20 20 STUDENT TRAINING MANUAL Review Questions 1. An application for service must be made through SaskPower. 2. An application must include a site plan with the location of the service entrance. 3. A written notice to make alterations to a new installation is a: (a) Form K. (b) Form G. (c) Electric Permit. (d) Electric Service Disconnect Order. 4. Authorization to provide service to a customer following an inspection of the installation is a: (a) Form K. (b) Form G. (c) Electric Permit. (d) Electric Service Disconnect Order. 5. Written notice to make alterations to existing wiring is a: (a) Form K. (b) Form G. (c) Electric Permit. (d) Electric Service Disconnect Order. 6. A requirement for reconnection of services which have been disconnected for over one year is a: (a) Form K. (b) Form G. (c) Electric Permit. (d) Electric Service Disconnect Order. 7. A document issued when an order to correct a defect or hazard has not been complied with is a: (a) Form K. (b) Form G.

21 SINGLE-PHASE METER INSTALLATION 21 (c) (d) Electric Permit. Electric Service Disconnect Order. 8. Ensure the meter socket is secure before installing the meter. 9. Verify a Form K has been issued prior to a meter installation. 10. Ensure the Measurements Canada seal has been removed prior to the meter installation. 11. An inspection of the ground connections in the meter socket and ground rod should be completed prior to the meter installation. 12. The final meter height from the finished grade is to be 1.7m. 13. The final meter height from the finished grade is to be 2.0m. 14. Ensure live incoming wires are connected to the load side terminals of the meter socket and the customer wires are connected to the line side terminals of the meter socket. 15. Three items to check after a meter installation are: (a) Proper grounding, proper voltage, and meter creep. (b) Disc rotation, light load starting, and meter creep. (c) Vibration (d) Final grade, Form G, and light load starting. 16. When a meter turns under no load conditions, it is called: (a) Disc rotation. (b) Demand. (c) Meter creep. (d) An energy meter. 17. A meter that is working properly should start rotating with as little as 15 watts connected to it.

22 22 STUDENT TRAINING MANUAL 18. A meter that is working properly should start rotating with as little as 0 watts connected to it. 19. A reversed rotation on the meter disc indicates meter creep. 20. On a five dial meter, the middle dial reads kilowatt-hours by: (a) Tens. (b) Twenties. (c) Hundreds. (d) Thousands. 21. A customer who is metered by a demand meter is billed by a demand reading only. 22. A consumption meter or kilowatt hour meter measures the amount of energy used. 23. A consumption meter or kilowatt hour meter measures the amount of kva used. 24. A demand meter measures the kva required. 25. A demand meter measures the energy required. 26. The standards division requires that all meters be calibrated to ensure that an error in registration does not exceed +/- 2% or +/- 1% for electronic meters. 27. A meter which is involved in a customer initiated dispute must be accurate to within plus or minus: (a).5%. (b) 2%. (c) 3%. (d) 5%. 28. A customer initiated dispute may originate from the use of faulty equipment. 29. A dispute test can be completed with the meter left in its original location.

23 SINGLE-PHASE METER INSTALLATION If a dispute test is required, the meter is sent to the meter repair shop where it is tested and inspected.

24 24 STUDENT TRAINING MANUAL Review Question Solutions 1. T 2. T 3. Form K. 4. Electric Permit. 5. Form G. 6. Electric Permit. 7. Electric Service Disconnect Order. 8. T 9. F 10. F 11. T 12. T 13. F 14. F 15. Disc rotation, light load starting, and meter creep. 16. Meter creep. 17. T 18. F 19. F 20. Hundreds. 21. F 22. T

25 SINGLE-PHASE METER INSTALLATION F 24. T 25. F 26. T 27. 3%. 28. T 29. F 30. F