Electrical Services, Grounding, and Bonding (Residential)

Flashcards covering terminology and compliance rules for residential electrical services, grounding, and bonding according to the Canadian Electrical Code.

What are the three distinct parts of a residential service?

The supply service, the consumer's service, and the service box.

What is a combination panelboard in a single dwelling installation?

An enclosure that incorporates both a service box and a panelboard, with the two separated by a metal barrier.

What does the term "readily accessible" mean?

Being capable of being reached quickly for operation, renewal, or inspection without the need to climb over obstacles or use portable tools like ladders or chairs.

What is the function of a service head (weatherhead)?

A waterproof cap located on the upper portion of a conduit or tubing that prevents the ingress of moisture.

What is the definition of bonding?

A low impedance path obtained by permanently joining all non-current-carrying metal parts to ensure electrical continuity and the capacity to safely conduct fault current.

What is the maximum permitted horizontal distance from the service head to the point of attachment on an overhead service?

$$600\,mm$$

According to Rule $6-112$, what is the maximum height of the point of attachment for supply service conductors?

$$9\,m$$

What is the minimum clearance between exposed service conductors and doors, windows, or porches?

$$1\,m$$

What is the minimum emergence length of conductors from the consumer's service head above the support attachment for the overhead conductors?

$$150\,mm$$

What is USEB90 cable?

Underground service entrance cable with a bare neutral conductor, commonly used for residential underground services.

What is the minimum burial depth for a PVC raceway in a pedestrian traffic area?

$$450\,mm$$

What is the minimum burial depth for a PVC raceway located under a driveway?

$$600\,mm$$

Under what conditions is metering equipment permitted on the supply side of a service box?

The supply must be AC, not exceed $300\,V$ between conductors, and the rating must not exceed $200\,A$ (or $320\,A$ if equipped with a bypass).

What is the minimum length for metering loops left inside an enclosure according to Rule $6-402$?

$$450\,mm$$

What is the minimum size for a copper grounding conductor connected to a grounding electrode conforming to Rule $10-102$?

$$No.\,6\,AWG$$

How many ground rods are required for a single dwelling installation, and what is their minimum spacing?

A minimum of two rod electrodes must be driven to their full length and spaced at least $3\,m$ apart.

What is the minimum burial depth for a plate style grounding electrode in direct contact with soil?

$$600\,mm$$

What defines an "in situ" grounding electrode?

Something "already in place" that functions as an electrode, such as a copper water service pipe, steel well casing, or metallic reinforcing bars.

What is "touch potential"?

The voltage that might exist between any two conductive objects that can be contacted simultaneously, such as hand-to-hand or hand-to-shoulder.

What is the intent of equipotentiality?

To minimize the likelihood of a touch potential between two conductive objects by ensuring they are at a substantially equal electric potential.

What is the minimum size for a copper bonding conductor used for interior metallic gas piping?

$$No.\,6\,AWG$$

What is the purpose of a system bonding jumper according to Section 10?

To provide a connection between the point of an electrical system to be solidly grounded and the non-current-carrying conductive parts of that system.

What defines a separately derived system?

An electrical system in which circuit conductors have no direct connection to the supply authority system's circuit conductors, excluding grounding and bonding connections.

What is the minimum clearance for overhead service conductors run over a residential driveway?

$$4.0\,m$$

How far above grade must a rigid conduit extend when used to protect cables rising from an underground service?

At least $2\,m$