Electrical Power & Distribution

Mech/Elec

Conduit Bending & Installation

Item	Value
EMT deduct ¾"	6" (stub-up)
EMT deduct 1"	8" (stub-up)
30° offset multiplier	2× depth; shrink ¼"/in
22.5° offset multiplier	2.6× depth; shrink 3/16"/in
3-point saddle	45° centre + two 22.5° returns
EMT support spacing	1.5 m max; within 1.5 m of box
Rigid support spacing	Up to 3 m (size-dependent)
Expansion fittings	Every 30 m & at bldg exp. joints

Conduit Fill (OESC)

1 conductor	53% max
2 conductors	31% max
3+ conductors	40% max (target 30% for runs >15 m)

Conduit Selection

Rigid (RMC): Service entrance, direct burial, severe damage areas
IMC: Exposed mech rooms, rooftop, exterior wall-mount
EMT: Concealed runs, above ceiling, interior exposed

Conductor Colour Coding (OESC)

System	A / B / C	Neutral	Ground
120/208V	Blk / Red / Blue	White	Green/bare
347/600V	Org / Brn / Yel	Wht w/ stripe	Green
Isolated gnd	—	—	Green/yellow

Voltage Drop (OESC 8-102)

Total (service to outlet)	5% max
Branch circuit	3% max

Termination Torque Values

Connection	Torque
15A/20A receptacles & switches	1.6–2.0 N·m (14–18 in-lb)
Branch breaker terminals	2.5–5.0 N·m (per mfr.)
Large lugs (100A+)	30–50 N·m (per mfr.)

Aluminum: Anti-oxidant compound required on all terminations.

Panels & Distribution

Panelboard: 42-circuit 208/120V 3φ typical for mid-size church
Switchboard: Where service > 400A or multiple sub-panels
One-line diagram: Must be posted at main switchgear
Panel clearance: 1 m min. working space in front (OESC)
Panel schedules: Complete, accurate, legible — typed, not handwritten
AV system: Dedicated panel with isolated-ground circuits

Emergency & Exit Lighting

Exit signs: min. 1 lux at floor (OBC 3.2.7); green running-man pictogram
Emergency lighting: 30-min or 2-hr battery backup per OBC
Monthly 30-sec test; annual 30-min (or 2-hr) full discharge test
Generator: auto transfer within 10 sec; weekly no-load test + monthly load test

Grounding & Bonding

System grounding electrode: per OESC Rule 10
Equipment bonding: all metallic raceways, boxes, enclosures
Ground rod: min. 3 m copper-clad, driven full depth
Grounding conductor: sized per OESC Table 16
Bonding jumper at water meter (metallic water pipe system)
Isolated ground for AV/sound: separate conductor back to panel

Underground Electrical

Min. burial depth: 600 mm (rigid); 450 mm (PVC under concrete)
PVC conduit: Schedule 40 above grade transition, DB2 below grade
Warning tape: 300 mm above all buried conduit
Sand bedding: 75 mm above and below conduit

Code References

OESC (CSA C22.1): Ontario Electrical Safety Code — all electrical work
ESA: Electrical Safety Authority — inspections & enforcement
CSA Z462: Workplace Electrical Safety — arc flash, LOTO, PPE
CSA S832: Seismic restraint of non-structural components
OBC 3.2.7: Emergency lighting & exit signage
OESC Table 2: Conductor ampacities
OESC Table 5A–5C: Derating factors
OESC Rule 8-102: Voltage drop limits

Safety — Do Not Forget

Compulsory trade: Licensed electrician; ESA inspection required.
Arc flash (CSA Z462): Risk assessment on all panels ≥208V. Arc-rated PPE mandatory near energized equipment.
LOTO: De-energize, lock out, tag out, verify zero energy before any work. No exceptions.
Torque all terminations with calibrated tools — loose connections cause arcing and fire.
Never use petroleum-based wire lubricant — degrades insulation.
Firestopping: ULC-listed system at every fire-rated penetration.

Pro Tips

Pull a spare string through every conduit run for future circuit additions.
Bend offsets in pairs: Lay two sticks side-by-side, mark identically, bend together.
Oversize conduit by one trade size on long runs — cheap insurance for future capacity.
Label both ends of every conductor during wire pull — saves hours at termination.
Fibreglass fish tape only near energized circuits.