309A Study Guide 2026
Everything you need to pass the 309A exam in one place: the exam format, every topic to study, real practice questions with explanations, flashcards, and full-length practice tests. Free, no sign-up needed.
📋 309A Exam Format at a Glance
📚 309A Topics to Study (39)
✍️ Sample 309A Questions & Answers
1. What type of cable is designated TECK90 used for in Canadian electrical installations?
TECK90 cable is an armoured cable widely used in Canadian industrial installations. It can be used in wet or dry locations, exposed or concealed, and its interlocking armour provides mechanical protection.
2. What is the maximum ambient temperature rating for standard NMD90 cable insulation?
NMD90 cable insulation is rated for a maximum temperature of 90°C, as indicated by the '90' in its designation. However, ampacity is typically limited to 60°C terminal ratings.
3. What does a motor's nameplate 'code letter' indicate?
The NEMA code letter on a motor nameplate indicates the locked-rotor kVA per horsepower, which determines the inrush current when the motor starts. Higher code letters indicate higher inrush.
4. According to the CEC, what is the minimum size of a copper grounding electrode conductor for a 100 A service?
CEC Table 17 specifies a minimum No. 6 AWG copper grounding electrode conductor for services up to 100 A, ensuring adequate capacity to carry fault current to the grounding electrode.
5. What is the maximum permitted ground resistance for a single ground rod according to the CEC?
CEC Rule 10-702 requires a maximum ground resistance of 25 Ω for a single grounding electrode. If this cannot be achieved, additional electrodes must be installed.
6. According to CEC Rule 26-710, what type of receptacle is required in a bathroom within 1 m of a sink?
CEC Rule 26-710 mandates GFCI protection for receptacles installed within 1.5 m of sinks and in bathrooms to protect against electric shock in wet locations.