Wire it right the first time.
Plain-language, code-aware how-tos for homeowners and DIYers — from swapping a receptacle to sizing a circuit — plus live calculators so you check the numbers before you touch a wire.
Educational reference only — not a substitute for your local Authority Having Jurisdiction (ESA in Ontario), a permit, or a licensed electrician where required.
Baseline copper ampacity, 60°C column, single 3-conductor NMD90 cable — no bundling, ambient-temperature, or run-length derating applied. Always verify against the current CEC and your local ESA amendments before sizing a real circuit.
Derating, permits, and inspections are exactly where DIY gets risky — Durham Region & the GTA.
Hire an Electrician →Step-by-step guides
Each guide covers tools, code requirements, and the exact steps — flagged by skill level.
See all guides →Plugs & Receptacles
Confirm the circuit is dead, match the device rating, and land the wires correctly — the most common first DIY job.
IntermediateLighting, Switches & Fixtures
Single-pole, 3-way, and 4-way switching, dimmers, smart-switch neutrals, fixture swaps, and ceiling fans.
BeginnerPanels & Breakers
Warning signs you've outgrown your panel, how to size a new service, and whether fuse panels are safe.
BeginnerKitchen & Bathroom Rules
Countertop circuit counts and spacing, split receptacles, GFCI radius, and switch clearance from a tub.
BeginnerSmoke & CO Alarms
Placement requirements, interconnection rules, and why alarms tie into a lighting circuit.
BeginnerTroubleshooting Common Problems
Flickering lights, tripping breakers, warm outlets, burning smells, and sudden bill spikes.
Reference GuideAFCI & GFCI: What Needs What
A panel diagram mapping which circuits need AFCI, GFCI, both, or typically neither.
Permit requiredDetached Garage, Shed & Gazebo Power
Direct burial depths by project, disconnects, bonding — and why pool equipment is a no-DIY zone.
The Riley Group Electrical
Licensed electricians serving Durham Region and the surrounding GTA. This site is the free how-to arm of our business — when a job goes past DIY, hire us directly.
Working calculators
Live tools that update as you type — the Ohm's Law solver above is the first. More are on the way.
See all calculators →Ohm's Law Solver
Enter any two of V, I, R — solves the rest plus wattage in real time.
Wire Gauge & Ampacity (NMD90)
Match conductor size to breaker rating — copper NMD90, CEC Table 2.
● LiveBreaker Size
Watts or amps in — minimum standard breaker out, with the 125% continuous-load rule built in.
● LiveVoltage Drop
Check run length against conductor size — flags anything over the 3%/5% guideline.
Panel Load Calculation
Estimate total demand load for a dwelling per CEC Section 8.
Klein NCVT-4IR Non-Contact Voltage Tester
Before touching any wire or outlet, verify it's dead. Beeps and lights up on contact — no probes needed. The one tool every homeowner should own.