Welcome!

Installation Rules Course

A comprehensive guide for Installation Rules P1 and P2 calculations for all 2022 - 2024 papers.

  • Videos: 18
  • Duration: 2h 45m
  • Updated: March 2025
Recent Updates:
Study Guide
26 May 2025

Apr 2025 P2 exam paper now referenced to the P2 study guide.

Past Papers
22 May 2025

Apr 2025 past papers added.

Notes
10 May 2025

Latest SANS 10142-1: 2024 Edition 3.2 added for reference.

Study Guide
28 Mar 2025

Apr 2025 P1 exam paper now referenced to the P1 study guide.

Videos P1


    This section on determining the size of the conductors appears in both Paper 1 and Paper 2 of the exam.

    Determining of Conduit Size Exam Questions Tracking (2015-2025)
    # Chapter Year Term Question Paper Notes
    1 Conductors in Conduit 2015 Aug Question 7 Paper 1 Calculations Memo is accurate
    2 Conductors in Conduit 2016 Aug Question 2 Paper 1 Calculations Status: ---
    3 Conductors in Conduit 2017 Apr Question 8 Paper 1 Calculations Memo is accurate.
    4 Conductors in Conduit Assignment 1 2018 Aug Question 3 Paper 1 Calculations Memo is accurate
    5 Conductors in Conduit Assignment 2 2019 Apr Question 7 Paper 1 Calculations Memo Errors:
    7.1.1: 5 × 14 should be = 70 and not 85
    7.2: Could be worded better: "How many 25mm conduits can you use for these circuits while leaving at least 15% (or more) space in each conduit?"
    6 Conductors in Conduit Assignment 3 2019 Nov Question 5 Paper 1 Calculations Memo Error:
    5.2: 3 × 6mm² + 6 × 1.5mm²
      = (3 × 22) + (6 × 10)
      = 126 (25mm conduit)
    7 Conductors in Conduit 2020 Nov Question 10 Paper 1 Calculations Comparison: Slightly similar to Apr 2019 Q7
    8 Conductors in Conduit 2022 Aug Question 10 Paper 2 Calculations Key Concept:
    • Minimum earthing conductor should not be more than 50% smaller than Live wire
    Rule: 2.5mm² is the smallest allowed
    Reference: See Video
    9 Conductors in Conduit 2023 Nov Question 9 Paper 2 Calculations Reference: See Video
    10 Conductors in Conduit 2024 Aug Question 7 Paper 1 Calculations Method: Use Table 6.27 (Maximum protection rating for nominal cross-sectional area of small conductors)
    Application: Get cable size from 25A circuit breaker
    11 Conductors in Conduit Assignment 4 2024 Nov Question 9 Paper 1 Calculations Comparison: Similar to Nov 2019 QP
    Memo Errors:
    9.2: Second part should be (2 × 3 × 10)
    9.3: Wrongly calculated, final answer should be 249
    #1
    2015 Aug
    Conductors in Conduit
    Question 7 Paper 1 Calculations

    Memo is accurate

    #2
    2016 Aug
    Conductors in Conduit
    Question 2 Paper 1 Calculations

    ----

    #3
    2017 Apr
    Conductors in Conduit
    Question 8 Paper 1 Calculations

    ---

    #4
    2018 Aug
    Conductors in Conduit Assignment 1
    Question 3 Paper 1 Calculations

    Memo is accurate

    #5
    2019 Apr
    Conductors in Conduit Assignment 2
    Question 7 Paper 1 Calculations

    Errors: 7.1.1: 5×14=70 not 85
    7.2: Could be worded better for clarity

    #6
    2019 Nov
    Conductors in Conduit Assignment 3
    Question 5 Paper 1 Calculations

    Error: 5.2 calculation wrong in memo

    #7
    2020 Nov
    Conductors in Conduit
    Question 10 Paper 1 Calculations

    Compare: Slightly similar to Apr 2019 Q7

    #8
    2022 Aug
    Conductors in Conduit
    Question 10 Paper 2 Calculations

    Rule: Earth conductor ≤50% smaller than Live wire
    Min: 2.5mm² smallest allowed

    #9
    2023 Nov
    Conductors in Conduit
    Question 9 Paper 2 Calculations

    Method: Use Table 6.27 for cable size from 25A CB

    #10
    2024 Aug
    Conductors in Conduit
    Question 9 Paper 1 Calculations

    Method: Use Table 6.27 for cable size from 25A CB

    #11
    2024 Nov
    Conductors in Conduit Assignment 4
    Question 9 Paper 1 Calculations

    Compare: Similar to Nov 2019
    Errors: 9.2: should be (2×3×10), 9.3: answer=249


    • Table 6.23 & 6.24
      Table 6.23 — Values of C for conductor nominal cross-sectional area
      Table 6.24 — Values of K for conduit diameter
      Page 148: SANS 10142-1 2024 Edition 3.2

    Determining of Conduit Size: SANS 10142-1
    Assignment 1

    Aug 2018 Q3

    Assignment 2

    Apr 2019 Q7

    Assignment 3

    Nov 2019 Q5

    Assignment 4

    Nov 2024 Q9


    Estimated Load Exam Questions Tracking (2015-2025)
    # Chapter Year Term Question Paper Notes
    1 Estimated Load 2015 Apr Question 3 Paper 1 Calculations Memo is accurate, not too different from posted videos
    2 Estimated Load 2015 Aug Question 6 Paper 1 Calculations Memo is accurate, not too different from posted videos
    3 Estimated Load 2015 Nov Question 3 Paper 1 Calculations Memo is unavailable, but this question is not too different from posted videos
    4 Estimated Load 2016 Aug Question 8 Paper 1 Calculations Memo Analysis: Accurate
    Key Concept: Spare capacity for lights is multiplied by 2 to convert back to connected load before applying diversity factors
    5 Estimated Load Assignment 1 2016 Nov Question 3 Paper 1 Calculations Memo Analysis: Accurate
    Key Concept: Spare capacity for lights is multiplied by 2 (or 0.5) to convert back to connected load before applying diversity factors
    6 Estimated Load Assignment 2 2017 Apr Question 3 Paper 1 Calculations 3.1: Typing error: 3900 W should be 2900 W
    3.2: Typing error: 3150 should be 2900
    Calculations:
    • IBalance = P/V = 2900/230 = 12.61 A
    • IHeaters = P/V = 2500/230 = 10.87 A
    • Ratio = 12.61/10.87 = 1.16
    7 Estimated Load Assignment 3 2018 Aug Question 2 Paper 1 Calculations Key Points:
    • Diversity factor for AC = 1 (not in SANS 10142-1 list)
    • Typing error: 23 V × 60 A should be 230 V × 60 A
    8 Estimated Load Assignment 4 2019 Nov Question 4 Paper 1 Calculations Memo Analysis:
    • Accurate application of estimated connected load
    • Correct use of diversity factors
    Rule: Multiply lights by 60W unless specified otherwise
    9 Estimated Load 2020 Nov Question 9 Paper 1 Calculations The memo is unavailable, but it looks fairly easy to solve.
    10 Estimated Load 2021 Aug Question 8 Paper 1 Calculations Issue: Requested "Connected load" but intended "Estimated load"
    Reference: Discussed in Apr 2025 Q8 video
    11 Estimated Load 2022 Nov Question 10 Paper 1 Calculations Note: Correct application of the Estimated Load calculation with diversity factors. See video
    12 Estimated Load 2023 Nov Question 8 Paper 1 Calculations Note: This is the correct application of the Estimated Load calculation with diversity factors. See video
    13 Estimated Load 2024 Apr Question 8 Paper 1 Calculations Repost clearer video... Note: Correct application of the Estimated Load calculation with diversity factors. See video
    14 Estimated Load 2024 Aug Question 8 Paper 1 Calculations Comparison:
    • Nov 2019 QP: Correctly asks for "estimated load" using diversity factors
    • This QP: Asks for "connected load" but still multiplies by DFs (incorrect)
    Reference: Issue discussed in Apr 2025 Q8 video
    15 Estimated Load Assignment 5 2024 Nov Question 8 Paper 1 Calculations Issues:
    • Wrong diversity factor for oil heater (heating)
    • Requested "Connected load" but intended "Estimated load"
    Reference: Discussed in Apr 2025 Q8 video
    16 Estimated Load 2025 Apr Question 8 Paper 1 Calculations Issues Identified:
    • Requested "Connected load" but intended "Estimated load"
    • Connected load amps too high for circuit breaker
    Geyser Error: QP states 4kW, memo uses 2kW
    Key Reminders:
      – 1 Horsepower = 750W
      – Discuss 60W changes in latest SANS
    #1
    2015 Apr
    Estimated Load
    Question 3 Paper 1 Calculations

    Memo is accurate, not too different from posted videos

    #2
    2015 Aug
    Estimated Load
    Question 6 Paper 1 Calculations

    Memo is accurate, not too different from posted videos

    #3
    2015 Nov
    Estimated Load
    Question 3 Paper 1 Calculations

    Memo is unavailable, but this question is not too different from posted videos

    #4
    2016 Aug
    Estimated Load
    Question 8 Paper 1 Calculations

    Memo is accurate. Note: Spare capacity for the lights is multiplied by 2 to bring it back to the connected load value before it is multiplied by the diversity factor to bring it to the estimated load value.

    #5
    2016 Nov
    Estimated Load Assignment 1
    Question 3 Paper 1 Calculations

    Memo is accurate. Note: Spare capacity for the lights is multiplied by 2 (or by 0.5 in this case) to bring it back to the connected load value before it is multiplied by the diversity factor to bring it to the estimated load value.

    #6
    2017 Apr
    Estimated Load Assignment 2
    Question 3 Paper 1 Calculations

    3.1: Typing error: 3900 W → 2900 W
    3.2: Typing error: 3150 → 2900
    Calc: IB=2900/230=12.61A, IH=2500/230=10.87A, Ratio=1.16

    #7
    2018 Aug
    Estimated Load Assignment 3
    Question 2 Paper 1 Calculations

    Key: AC diversity factor = 1 (not in SANS list)
    Error: 23 V × 60 A → 230 V × 60 A

    #8
    2019 Nov
    Estimated Load Assignment 4
    Question 4 Paper 1 Calculations

    Memo: Accurate application of estimated load
    Rule: Lights = 60W unless specified otherwise

    #9
    2020 Nov
    Estimated Load
    Question 9 Paper 1 Calculations

    The memo is unavailable, but it looks fairly easy to solve.

    #10
    2021 Aug
    Estimated Load
    Question 8 Paper 1 Calculations

    Issue: "Connected load" vs "Estimated load" confusion
    Ref: Apr 2025 Q8 video

    #11
    2022 Nov
    Estimated Load
    Question 10 Paper 1 Calculations

    Note: Correct application of the Estimated Load calculation with diversity factors. See video

    #12
    2023 Nov
    Estimated Load
    Question 8 Paper 1 Calculations

    Note: This is the correct application of the Estimated Load calculation with diversity factors. See video

    #13
    2024 Apr
    Estimated Load
    Question 8 Paper 1 Calculations

    Repost clearer video... Note: Correct application of the Estimated Load calculation with diversity factors. See video

    #14
    2024 Aug
    Estimated Load
    Question 8 Paper 1 Calculations

    Compare: Nov 2019 (correct) vs this QP (incorrect)
    Issue: "Connected load" but still uses DFs
    Ref: Apr 2025 Q8 video

    #15
    2024 Nov
    Estimated Load Assignment 5
    Question 8 Paper 1 Calculations

    Issues: Wrong DF for oil heater + "Connected" vs "Estimated"
    Ref: Apr 2025 Q8 video

    #16
    2025 Apr
    Estimated Load
    Question 8 Paper 1 Calculations

    Issues: "Connected" vs "Estimated" + CB too high + Geyser error (4kW vs 2kW)
    Key: 1 HP = 750W, discuss 60W changes


    • Annex C
      Example of assessing estimated load for residential type installations
      Page 284 : SANS 10142-1 2024 Edition 3.2
    • Diversity Factors
      The appropriate of the diversity factors can be applied to the connected load to assess the estimated load
      Page 285 : SANS 10142-1 2024 Edition 3.2

    Estimated and Connected Load: SANS 10142-1
    Assignment 1

    Nov 2016 Q3

    Assignment 2

    Apr 2017 Q3

    Assignment 3

    Aug 2018 Q2

    Assignment 4

    Nov 2019 Q4

    Assignment 5

    Nov 2024 Q8

Videos P2

Resources

Educational Resources