CIC Grade A Electrical Trade Test flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Grade A scope

Covers general-use electrical work up to 600 V plus special high-voltage work up to 7,000 V for certain installations; Grade B is limited to 600 V or less general-use work.

Insulation resistance limit

A 300 V or less circuit must read 0.1 MΩ or more with a 500 V insulation tester; 300 V to 750 V circuits require 0.2 MΩ or more.

Voltage drop single-phase

e = 2 × L × I × r, where L is one-way length in meters, I is current, and r is conductor resistance per meter; keep branch drop within 2%.

Conduit fill 40% rule

For three or more conductors, total conductor cross-sectional area must not exceed 40% of the conduit internal area; two conductors 33%, one conductor 53%.

Three-way switch wiring

A 3-way switch has a common terminal and two traveler terminals; the common connects to the source or load, and travelers run between the two switches.

Grounding classes A C D

A-class grounding applies to 400 V circuits and requires 10 Ω or less; C-class 100 Ω or less for 200 V; D-class 500 Ω or less for low-current 300 V circuits.

Leakage breaker sensitivity

Select 30 mA or less sensitivity for human protection on wet-location and outdoor circuits, and 200 mA or less for fire protection of circuits.

Cable derating factors

Multiply the base ampacity by the ambient temperature correction factor and the grouping factor for the number of circuits in the same raceway; never add them.

Practical exam time limits

The practical exam allows 40 minutes for the standard problem and 60 minutes for the composite problem; unfinished work is scored as incomplete.

VVF cable ampacity

A 2.0 mm² VVF cable in conduit carries about 24 A at 30 °C; a 1.6 mm² cable carries about 17 A; apply derating for higher ambient and grouping.

Pilot lamp connection

Connect the pilot lamp in parallel with the load so it indicates whether the load is energized; never connect it in series with the load.

Firestop penetration rule

Seal every penetration of a fire-rated wall or floor with a material rated for the same fire resistance as the wall or floor.

Power factor correction formula

Required capacitor kvar = P × (tan θ1 − tan θ2), where θ1 is the original angle and θ2 is the target angle.

Cable bending radius

For fixed low-voltage cable, keep the inner radius at 6 times the cable diameter or more; for movable or flexible cable, 4 times or more.

Single-phase load current

I = P / (V × power factor); for a 100 V, 1 kW load at unity power factor, the current is 10 A.

Cable support spacing

Support VVF cable at intervals of 2 m or less, and within 1 m of each box or fitting; in a vertical shaft, support at every floor.

Grounding conductor sizing

The grounding conductor must be at least the phase conductor up to 16 mm², and at least half the phase conductor for larger sizes, per the 内線規程.

Switch height residential

In Japanese residential practice, switches are about 1,200 mm above floor, outlets about 300 mm, and kitchen counter outlets about 1,000 mm above the counter.

Three-phase load current

I = P / (√3 × V × power factor); for a 200 V, 5 kW load at 0.8 power factor, the current is about 18 A.

Conduit bend limit

The total bend between pull points must not exceed 360 degrees, and every bend must be made with a bender to avoid kinking.

Neutral and ground bars

In a subpanel, the neutral bar and ground bar must be separate; they are bonded only at the main service panel.

Cable tray fill limits

The total cable cross-section must not exceed 40% of the tray's usable cross-section for power cables, and 50% for control cables.

Transformer efficiency

η = output / input × 100%; losses are copper loss, proportional to current squared, plus iron loss, which is constant.

Emergency lighting duration

Emergency lighting must maintain 30 minutes of illumination at 1 lx or more on the floor of the evacuation route, per the 消防法.

Cable stripping lengths

Strip about 15 mm for a ring sleeve and 10 mm for a push-in connector; exposed copper strands after termination are a defect.

Switchboard working space

Maintain at least 1.2 m of working space in front of a switchboard, and 0.8 m at the sides and rear where access is required.

Motor overload relay setting

A thermal overload relay in a magnetic contactor provides overload protection; set it to the motor's rated current.

Grounding resistance measurement

Use the fall-of-potential method with two auxiliary electrodes spaced at least 20 m apart for accurate results.

Illuminance targets

Required illuminance is about 100 lx for a living room, about 300 lx for a kitchen, and about 500 lx for an office.

Cable color code

In a three-phase system, black, red, and blue are the three phases, white is neutral, and green is ground; green is never a live conductor.

Breaker coordination rule

The breaker rating must be less than or equal to the cable's allowable current after derating, and greater than the load current.

Insulation test voltage

Use 500 V for 300 V or less circuits and 1000 V for 300 V to 750 V circuits; never use a higher voltage than the circuit rating.