Alberta Master Electrician exam, Part 2: CEC Calculations practice questions.

Ten free practice questions on Canadian Electrical Code calculations, for Part 2 (Canadian Electrical Code) of Alberta's Master Electrician exam, which the Safety Codes Council runs. We group the exam's two parts into four study units of our own, and this is Unit D. These are original questions written by TicketPrep from the documents in the Council's 2024 Exam Kit and the rule numbers of the Canadian Electrical Code, not questions from the exam. Each has four options and one correct answer, as every question in our bank does. Answer each one before opening the explanation. No account, no email.

01The questions

1. Calculation · Objective D-1

   A 64 m² apartment unit has a 12 kW range, 6 kW of baseboard heat with room thermostats, a 5 kW dryer and a 30 A EVSE (7200 W at 240 V) supplied from the unit's own panel; there is no air conditioning or EVEMS, and hot water is central. What is the calculated load of the 120/240 V feeder to this unit, to 0.1 A?

   1. 76.0 A
   2. 106.0 A
   3. 113.5 A
   4. 131.0 A
   Show the answer

   B. Correct. Rule 8-202 1) a): 3500 W for the first 45 m² + 1500 W for the second 45 m² = 5000 W; heating 6000 W (within the first 10 kW of Rule 62-118 3)); range 6000 W; dryer at 25 % = 1250 W; unit-panel EVSE at 100 % = 7200 W. Total 25 450 W / 240 V = 106.0 A, above the 60 A minimum. STANDATA 24-ECB-008 likewise takes suite EVSE at 100 % on suite feeders.

   Why not the others

   A. This leaves the EVSE out, as Rule 8-202 3) a) does when units are combined for a building service. For the unit's own feeder, Rule 8-202 1) a) vii) adds EVSE supplied from the unit's panelboard at 100 %: 25 450 W, 106.0 A.

   C. This adds a further 25 % to the EVSE as if the feeder had to carry it as a continuous load. Rule 86-302 makes only the EVSE branch circuit continuous; Rule 8-202 1) adds the EVSE once at 100 %, and Rule 8-202 2) keeps the unit load non-continuous: 106.0 A.

   D. This adds the range at its 12 kW rating. Rule 8-202 1) a) v) allows 6000 W for a single range of 12 kW or less, so the total is 25 450 W: 106.0 A.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 8-202; STANDATA 24-ECB-008

2. Procedural · Objective D-2

   A 20 A, 120 V branch circuit in a retail store, on a breaker marked for continuous operation at 80 %, will feed 22 duplex receptacles for a display-lighting system whose connected load is known to be 14.5 A. Under Rule 8-304, may the circuit serve these 22 outlets?

   1. Yes, since the known 14.5 A is within the breaker's 16 A limit
   2. No, since an 80 %-marked 20 A circuit is limited to 16 outlets
   3. No, since a known load still allows at most 20 outlets on 20 A
   4. Yes, but only with a breaker marked for 100 % operation
   Show the answer

   A. Correct. Rule 8-304 3) lets the outlet count exceed the Subrule 1) maximum where the connected load is known, provided the load current stays within the continuous operation marking of the breaker: 80 % of 20 A = 16 A, and 14.5 A is within it.

   Why not the others

   B. Sixteen outlets is the Rule 8-304 1) count for this circuit when the load is not known. With a known load, Rule 8-304 3) allows more outlets so long as the current stays within the breaker's 80 % marking (16 A).

   C. Twenty outlets is the count for a 20 A circuit on a 100 %-marked breaker. Rule 8-304 3) sets no outlet ceiling for a known load; it limits the current to the breaker's continuous marking.

   D. A 100 %-marked breaker raises the unknown-load count to 20 outlets, still short of 22. With the load known, the 80 %-marked breaker is enough because 14.5 A is within its 16 A continuous limit.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 8-304

3. Recall · Objective D-3

   An ME sizes a direct-buried 600 V feeder from Table D8A, whose values are based on a 90 °C conductor temperature, and terminates it on switchgear marked for 75 °C conductors. What does Rule 4-006 require?

   1. The whole run must be resized to the 75 °C column of Table 2 over its length
   2. Nothing more; the Table D8A values already allow for 75 °C terminations
   3. Nothing more; Rule 4-006 applies only to ampacities taken from Tables 1 to 4
   4. Its termination limit still governs the first 1.2 m from each terminal
   Show the answer

   D. Correct. Rule 4-006 6) applies the termination-temperature rule even where ampacity comes from Tables D8A to D11B, D17A to D17N or 12E, and Rule 4-006 4) confines it to the first 1.2 m from the terminal. The Appendix B note to 4-004 makes the same point: the D tables are 90 °C values, and 75 °C equipment may limit the size.

   Why not the others

   A. Rule 4-006 4) limits the termination rule to the first 1.2 m of conductor from the terminal; beyond that the underground ampacity from Table D8A stands.

   B. The D tables are calculated for a 90 °C conductor and say nothing about equipment terminals; Rule 4-006 6) expressly applies the termination limits to them.

   C. Rule 4-006 6) extends Subrules 1) and 2) to ampacities from Tables D8A to D11B, D17A to D17N and 12E, so the 75 °C terminations still govern near the switchgear.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rules 4-006, 4-004

4. Procedural · Objective D-4

   Under Rule 8-102 3), a dwelling's branch-circuit wiring may be accepted without a voltage-drop calculation when the conductor length is within the Table 68 value. In a new house, which circuit may be accepted that way?

   1. A 20 A, 120 V split circuit to kitchen counter receptacles
   2. A 15 A, 120 V circuit to bedroom and hallway receptacles
   3. A 15 A, 120 V circuit to the refrigerator receptacle
   4. A 40 A, 240 V circuit to the electric range
   Show the answer

   B. Correct. Rule 8-102 3) accepts a dwelling unit's general-use branch circuits rated no higher than 120 V or 20 A when the conductor run, from the service's supply side out to the farthest outlet, is within Table 68. The Appendix B note sets aside appliance, kitchen counter, heating and cooking, and dedicated medical-device circuits, which are calculated under 8-102 1).

   Why not the others

   A. The Appendix B note to Rule 8-102 3) sets kitchen counter receptacle circuits (Rule 26-656 d)) aside; they are checked under 8-102 1) with Table D3, on the connected load or one load of 80 % of the device rating at the far end.

   C. A refrigerator receptacle is a household-appliance circuit (Rule 26-654), which the Appendix B note to 8-102 3) leaves to the 8-102 1) calculation with Table D3.

   D. A range circuit is a cooking-appliance circuit rated above what Rule 8-102 3) covers; the Appendix B note sends it to the 8-102 1) calculation.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 8-102

5. Calculation · Objective D-5

   In an older school, the ME finds an existing conduit of an unlisted type whose internal diameter measures 40.0 mm, and Rule 12-910 lets its area be taken from the measured dimensions. With Table 8 allowing 40 % fill for three or more conductors, how many 1/0 AWG RW90 conductors (Table 6A: 119 mm² each) may it hold?

   1. 4 conductors
   2. 5 conductors
   3. 10 conductors
   4. 16 conductors
   Show the answer

   A. Correct. Rule 12-910 4) b) allows the interior area to be derived from measured internal dimensions: π × (40.0 / 2)² = 1257 mm². Table 8 allows 40 %: 0.40 × 1257 = 503 mm², and 503 / 119 = 4.2, so 4 conductors fit; a fifth would exceed the fill.

   Why not the others

   B. 4.2 rounded up gives 5, but five conductors occupy 595 mm², more than the 503 mm² that 40 % of the measured area allows; the count rounds down to 4.

   C. 10 conductors (1190 mm²) nearly fill the whole 1257 mm² area; Rule 12-910 4) holds the fill to the Table 8 percentage, 40 %, which allows 4.

   D. 16 comes from taking the area as π × 40.0², using the diameter where the radius belongs. The area is π × 20.0² = 1257 mm², and 40 % of it holds 4 conductors.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 12-910

6. Procedural · Objective D-6

   A small exhaust-fan motor at a car wash has a nameplate FLC of 4.2 A and full-voltage starting. Table 29 allows 250 % of FLC for an inverse-time breaker, which is 10.5 A. The ME plans a 15 A inverse-time breaker for its branch circuit. Under Rule 28-200, is that acceptable?

   1. No; the breaker may not exceed 10.5 A, so a 10 A device is the largest
   2. Yes; a 15 A device is allowed even where it exceeds the Table 29 value
   3. Only if the motor first fails to start on a smaller device, under Rule 28-200 4)
   4. Only if the motor is grouped with others on the circuit, under Rule 28-206 a)
   Show the answer

   B. Correct. Rule 28-200 3) a) holds the branch device to the Table 29 percentage but always allows a device rated or set at 15 A, even above that percentage. 250 % of 4.2 A is only 10.5 A, yet the 15 A breaker complies.

   Why not the others

   A. Table 29 sets the limit for larger motors, but Rule 28-200 3) a) adds a 15 A minimum that is always permitted. The 15 A breaker complies even though 250 % of FLC is 10.5 A.

   C. Rule 28-200 4) is the starting-relief step for a device that will not let the motor start. The 15 A allowance of Rule 28-200 3) a) needs no failed start; it applies directly.

   D. Rule 28-206 a) is the 15 A condition for grouping several motors on one branch circuit. For a single motor, Rule 28-200 3) a) already allows the 15 A breaker.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rules 28-200, 28-206

7. Calculation · Objective D-7

   A feeder of No. 10 AWG aluminum conductors will supply a small panelboard in a farm's well house. Unless another Rule allows more, what is the largest overcurrent device Rule 14-104 2) permits for these conductors?

   1. 15 A
   2. 20 A
   3. 25 A
   4. 30 A
   Show the answer

   C. Correct. Unless another Rule allows more, Rule 14-104 2) caps small conductors: No. 14 Cu at 15 A, No. 12 Cu at 20 A, No. 10 Cu at 30 A, No. 12 Al at 15 A and No. 10 Al at 25 A.

   Why not the others

   A. 15 A is the Rule 14-104 2) limit for No. 12 aluminum (and No. 14 copper). No. 10 aluminum may be protected at up to 25 A.

   B. 20 A is the Rule 14-104 2) limit for No. 12 copper. No. 10 aluminum may be protected at up to 25 A.

   D. 30 A is the Rule 14-104 2) limit for No. 10 copper. Aluminum of the same gauge carries less, and No. 10 aluminum is capped at 25 A.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 14-104

8. Calculation · Objective D-7

   A 150 kVA dry-type transformer, 600 V to 120/208 V three-phase, at a community hall is protected on the primary only. Using Table 13's rating column as the standard sizes, what is the largest primary breaker Rule 26-254 permits?

   1. 150 A
   2. 175 A
   3. 200 A
   4. 225 A
   Show the answer

   C. Correct. Rated primary current is 150 000 VA ÷ (1.732 × 600 V) = 144.3 A (physics). Rule 26-254 1) limits the primary device to 125 %, 180.4 A, and Rule 26-254 3) permits the next higher standard rating when that is not standard: 200 A.

   Why not the others

   A. This is the first standard rating above the 144.3 A rated primary current, a 100 % habit. Rule 26-254 allows 125 % (180.4 A) and then the next higher standard rating: 200 A.

   B. This rounds 125 % of rated primary current (180.4 A) down. Rule 26-254 3) permits the next higher standard rating where 125 % is not a standard rating: 200 A.

   D. This uses the 150 % limit of Rule 26-252 for transformers other than dry-type (216.5 A, then 225 A). A dry-type transformer is held to 125 % plus the next higher rating: 200 A.

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rules 26-254, 26-252

9. Procedural · Objective D-8

   At a 347/600 V service for a school, the service disconnect is an 800 A fusible switch fitted with 600 A fuses, and the service conductors have an ampacity of 840 A. The manufacturer's bonding strap is missing, so the ME will field-install the system bonding jumper. Table 16 gives copper No. 1 AWG for over 500 A up to 600 A and 1/0 AWG for over 600 A up to 800 A. What minimum copper jumper does Rule 10-616 1) require?

   1. No. 6 AWG
   2. 2/0 AWG
   3. 1/0 AWG
   4. No. 1 AWG
   Show the answer

   D. Correct. Rule 10-616 1) sizes a field-installed system bonding jumper from Table 16 on the ampere rating of the overcurrent device protecting the ungrounded conductors. Here that device is the 600 A fuse, not the 800 A switch that holds it: No. 1 AWG copper. If larger fuses are fitted later, the jumper must be re-checked.

   Why not the others

   A. No. 6 copper is the Rule 10-114 grounding-conductor minimum. A field-installed system bonding jumper is sized from Table 16 on the overcurrent device: No. 1 AWG for 600 A fuses.

   B. This enters Table 16 with the 840 A conductor ampacity (2/0 AWG for over 800 A up to 1000 A), the basis Rule 10-616 2) uses for a bonding conductor at service equipment. The system bonding jumper of 10-616 1) uses the 600 A fuses: No. 1 AWG.

   C. This sizes the jumper on the 800 A switch. A switch does not open by itself on overload or short circuit, so under the Section 0 definition the overcurrent device protecting the ungrounded conductors is the fuse, and the 600 A fuses fitted give No. 1 AWG under Rule 10-616 1).

   Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rules 10-616, 10-114, 10-210

10. Calculation · Objective D-9

    A 100 kVA single-phase transformer, 600 V to 120/240 V, with 2.5 % impedance, supplies a curling rink. Assuming an unlimited primary source and a bolted line-to-line fault at the 240 V secondary terminals, what is the estimated available fault current?

    1. 6.7 kA
    2. 9.6 kA
    3. 16.7 kA
    4. 33.3 kA
    Show the answer

    C. Correct. Full-load secondary current is 100 000 VA ÷ 240 V = 416.7 A, and with an unlimited source the fault current is that divided by the per-unit impedance: 416.7 ÷ 0.025 = 16.7 kA. This is physics; the CEC rule it feeds is Rule 14-012 a), which requires interrupting ratings at least this high.

    Why not the others

    A. This divides by the 600 V primary voltage (100 000 ÷ 600 ÷ 0.025). The fault is on the 240 V side: 416.7 A ÷ 0.025 = 16.7 kA.

    B. This inserts 1.732 as if the transformer were three-phase. Single-phase full-load current is 100 000 ÷ 240 = 416.7 A, and 416.7 ÷ 0.025 = 16.7 kA.

    D. This uses 120 V, the line-to-neutral voltage, for a line-to-line fault on the 240 V winding. At 240 V the estimate is 416.7 ÷ 0.025 = 16.7 kA.

    Source: SCC exam Part 2: Canadian Electrical Code (our Unit D); CEC Rule 14-012

02Answer key

03What Unit D covers

Unit D is the arithmetic half of Part 2, the Canadian Electrical Code part of the Safety Codes Council's exam. The Council publishes Part 2 as 70 questions on the CEC, Part I, 26th edition (2024), with no split between rules and calculations; Unit D is our own grouping of the calculation questions. They cover Section 8 service and feeder loads for dwellings, apartments and other occupancies, continuous loads and circuit limits, conductor ampacity, correction factors and termination temperatures, voltage drop with the Table D3 method, conduit, box and pull-box fill, motor, transformer and capacitor protection, bonding conductor sizing, and fault current, power factor and three-phase arithmetic. Every question gives the Rule it rests on and works the numbers in the explanation; where a step is plain physics rather than a Code rule, the explanation says so.

The Council publishes the two parts and their question counts, 50 and 70, and lists the documents the exam covers, but it does not say how many questions each document or topic gets. Unit D and Unit C together make up Part 2; the split between them, the nine objectives below and the right-hand column are TicketPrep's own. The column is how many questions our bank holds on each objective, Standard and Advanced together, not a count from the exam.

04What the questions turn on

A load calculation follows the Rule's order

Rule 8-202 builds an apartment unit's load from its floor area, then adds heating, the range, the dryer and any EVSE fed from the unit's own panel, each at its own demand factor, and compares the result with the Rule's minimum. Most wrong answers apply a demand factor to the wrong load or leave out the EVSE, which STANDATA 24-ECB-008 also takes at full rating on a suite feeder.

Continuous markings cap the load you may put on a circuit

A breaker marked for continuous operation at 80 per cent limits the known load on its circuit to 80 per cent of its rating. That decides whether a retail receptacle circuit may serve more outlets than the usual count (Rule 8-304) and how many baseboard heaters share one heating circuit (Rule 62-114).

Overcurrent sizing has floors and ceilings

Rule 14-104 2) caps the overcurrent device on small copper and aluminum conductors unless another Rule allows more, while Rule 28-200 always allows a 15 A device on a motor branch circuit even when the Table 29 percentage works out lower. A transformer protected on the primary only is held to 125 per cent of its rated primary current, moving up to the next standard rating where that figure is not one (Rule 26-254).

Size from the right number

A field-installed system bonding jumper is sized from Table 16 on the rating of the overcurrent device protecting the ungrounded conductors: the fuse in the switch, not the switch (Rule 10-616). An available fault current comes from physics, the transformer's full-load current divided by its per-unit impedance, and then Rule 14-012 asks whether the equipment is rated for it.

05The other units

To pass the Master Electrician exam you need at least 60 per cent on each of the two parts and a 75 per cent average of the two part scores, so a weak part fails the exam even when the average is high. Each of our units has its own page of free questions:

The Alberta Master Electrician practice test page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it. TicketPrep is not affiliated with the Safety Codes Council or CSA Group, and no CEC text is reproduced here: the questions cite Rule numbers and explain the requirement in their own words.