Learning Objectives

Notes

10.1
To know the basic properties of alternating current, to understand the differences between AC and DC circuits and to be able to state the advantages of AC over DC for commercial electrical distribution.

The teacher may once again wish to refer to the Electrical and Electronics 10, 20, 30 and Physics 30, curricula for ideas and guidance. Students could conduct web or library searches to develop basic knowledge, then interview local experts such as physics teachers, commercial or industrial electricians, or SaskPower personnel, to fill in the gaps.

Students could add new terminology to their glossary, if they began one in Module 9.

10.2
To be familiar with the voltages carried, visual appearance, location and total number of kilometres, for the various sizes of transmission lines in the Saskatchewan power grid.

Students could use the Internet, print or CD-ROM materials from local libraries or SaskPower offices to find the location, appearance, size and capacity of the transmission lines and towers in the province. Using graphs or tables, comparisons could be made with neighbouring jurisdictions, on both a total and a per capita basis.

Students could do a survey of transmission lines and switching stations in the area. Diagrams and models of different line structures and their components could be made. Theories about the need for and use of different components could be formulated and checked with resource people or reference materials.

10.3
To describe the control systems that regulate the SaskPower grid and identify the role of electrical substations in the power grid, including the purpose and function of step-up and step-down transformers.

Some information on control systems is available from the SaskPower website; exposure through a guided tour, or at least a film or video, would be preferable.

Students could visit a local substation under the guidance of a SaskPower employee and prepare a display or diagram of the facility.

Students could perform simple mathematical calculations on coil sizes and voltage ratios in transformers.

10.4
To describe and explain the process by which electricity is distributed from local transformers to residences, businesses and public buildings.

Students should be familiar with the appearance and characteristics of common types of transformers that convert 25KV or 14.4KV to 110/220VAC and be able to trace the path of the current from transformer to meter to service panel to outlets or appliances. Students should know the basis for selecting the size of electrical service panel required for a particular facility and be familiar with circuit load, conductor size and common methods of overload protection (including fuses, circuit breakers and GFI outlets). Students should understand the difference between two- and three-conductor circuits and the method by which 110VAC and 220VAC are obtained from the same service panel.

10.5
To recognize and read common types of electrical utility meters and calculate service fees based on meter readings and fee schedules.

Based on the information in the Customer Services section of the SaskPower website, the teacher or students could develop sample user scenarios and meter readings and practise calculating billing charges

Students could visit commercial establishments with demand meters and compare and contrast demand metering with normal residential supply metering.

Students could be provided with sample utility bills to analyze and interpret.

10.6
To describe the characteristics of the interprovincial power grid and explain how power outages and demand overload are handled to minimize service disruption.

Students could interview, email, or write letters to SaskPower officials to obtain this information.

Students could explore the implications of SaskPower's proposed Open Access Transmission Tariff in the context of import, export and carrying electricity on behalf of other owners or producers both inside and outside the province.

The role of large industrial and institutional users, such as IPSCO, potash mines, the Canadian Light Source (Synchrotron) and their impact on the power grid could be investigated.

10.7
To demonstrate familiarity with the job classifications and skill requirements of the workers who design, construct, maintain and operate the SaskPower grid.

Students could explore the Training Programs link on the SaskPower website to become familiar with the kinds of jobs, specific skill requirements and safety training features. In particular, the details of the Lineman Apprentice Program might provide useful information.

Much of the content of this objective overlaps that of Module 11; the difference is mainly one of emphasis. In the present module the focus is on operation of the system, while Module 11 looks at careers, training and safety requirements. The teacher may nevertheless wish to combine the relevant learning objectives into a single student activity.

10.8
To be familiar with the basis for assessing future electrical transmission needs for Saskatchewan and with the steps that must be taken before a new transmission line is constructed.

Students could contact their local MLA and/or SaskPower managers to become familiar with government and corporate priorities, planning and policy. Who determines whether new power lines and substations are needed? Who pays? Who has a say in determining location? Who makes the final decisions? Students could report their findings to the rest of the class.

Students could conduct a "Town Hall Meeting" dealing with a proposed power line or substation, in which they play the roles of various interest groups, e.g., homeowners, cottage owners, farmers, wildlife/environmental organizations, business interests, First Nations. Planning could include a local MLA, civic official, or SaskPower official as moderator or keynote presenter. See also L.O. 11.5.