Question 1

Is the power off at the breaker, and is it safe right now?

Accepted Answer

If you smell burning or see sparks, kill the breaker for that circuit (or the main if you're not sure which one) and tell the electrician what happened.

Question 2

Has a breaker tripped, or are you fully without power?

Accepted Answer

A single tripped breaker usually points to a circuit issue. Whole-house outage may be an incoming-supply or panel problem — useful info for the pro.

Question 3

How old is your electrical panel?

Accepted Answer

If your panel is 25+ years old or aluminium-wiring era, mention it. Some repairs require a panel upgrade first.

Question 4

Did anything happen right before the issue started?

Accepted Answer

A storm, water leak, or new appliance install often triggers electrical faults. Context narrows down the diagnosis.

Question 5

Are there pets or kids you need the pro to know about?

Accepted Answer

Open panels and exposed wiring are dangerous. Tell the electrician so they can plan workspace around little hands and curious noses.

Question 6

How much does an electrician cost in San Francisco?

Accepted Answer

Electrician rates in San Francisco, CA depend on the job. Compare local local electricians on HireLocal, see real rates and reviews, and get free quotes.

Question 7

How do I find a licensed electrician in CA?

Accepted Answer

HireLocal lists local electrician. Browse electricians in San Francisco, CA to see local, reviewed pros and get free quotes.

Question 8

When should I call an electrician vs doing it myself in San Francisco?

Accepted Answer

Any work beyond changing a light bulb or resetting a breaker should be done by a licensed electrician. In CA, electrical permits are required for most wiring changes. On HireLocal you can get free quotes from local electricians in San Francisco before deciding.

Question 9

What is a Master electrician?

Accepted Answer

An electrician who has met additional experience and exam requirements beyond the journeyman level. Masters can pull permits, run contracting businesses, and supervise journeymen and apprentices. Requirements vary by state.

Question 10

What is a Journeyman electrician?

Accepted Answer

An electrician who has completed an apprenticeship (typically 4–5 years) and passed the journeyman exam. They can work independently on most electrical work; requirements vary by state.

Question 11

What is a NEC code?

Accepted Answer

The National Electrical Code (NEC) is the U.S. standard for safe electrical installation. Electricians must follow NEC and local amendments. Updates are published every three years.

Question 12

What is a GFCI?

Accepted Answer

Ground fault circuit interrupter. A safety device that shuts off power when it detects current flowing to ground (e.g. through a person). Required in wet areas: kitchens, bathrooms, outdoors.

Question 13

What is a Electrical panel upgrade?

Accepted Answer

Replacing an outdated breaker panel (often 100-amp) with a higher-capacity panel (typically 200-amp) to safely support modern appliances, EV chargers, and HVAC systems. Required by code when total load exceeds panel capacity.

Question 14

What is a Arc-fault circuit interrupter (AFCI)?

Accepted Answer

A circuit breaker that detects dangerous electrical arcs caused by damaged or deteriorated wiring and shuts off power to prevent fires. The NEC requires AFCI protection in bedrooms, living rooms, and most habitable rooms in new construction.

Question 15

What is a Whole-house surge protector?

Accepted Answer

A device installed at the main electrical panel that diverts voltage spikes from lightning strikes, utility switching, or large appliance cycling, protecting electronics and appliances throughout the home.

Question 16

What is a EV charger installation?

Accepted Answer

Installing a Level 2 (240V) electric vehicle charging station at home. Requires a dedicated circuit (typically 40–50 amps), may trigger a panel upgrade in older homes, and must comply with local electrical codes. A licensed electrician should handle permitting and installation.

Question 17

What is a GFCI outlet?

Accepted Answer

A ground-fault circuit interrupter (GFCI) outlet monitors the electrical current flowing through it and cuts power within milliseconds if it detects current leaking to ground — preventing electrocution. GFCI outlets are required by NEC code in bathrooms, kitchens, garages, outdoor areas, laundry rooms, and anywhere within 6 feet of a water source. They're recognizable by their Test and Reset buttons. GFCI outlets should be tested monthly and replaced if the test function fails. Installation costs $100–$250 per outlet by a licensed electrician.

Question 18

What is a Dimmer switch?

Accepted Answer

An electrical switch that controls the brightness of a light fixture by reducing the voltage delivered to the bulb. Modern LED-compatible dimmers use trailing-edge technology and require LED-rated bulbs to avoid flickering or buzzing. Types include single-pole (one switch controls the light), three-way (two switches control the same light), and smart dimmers (Wi-Fi or Zigbee connected for app and voice control). A dimmer switch costs $15–$80 for the part and $50–$150 per switch for professional installation by a licensed electrician. Dimmers save energy, extend bulb life, and let you set the right mood in any room.

Question 19

What is a Low-voltage wiring?

Accepted Answer

Electrical wiring that carries 50 volts or less, as opposed to standard household 120V/240V line-voltage circuits. Common low-voltage systems in homes include doorbell wiring (16–24V), thermostat wiring (24V), landscape lighting (12V), security camera and alarm wiring, Ethernet and structured cabling (Cat5e/Cat6), speaker wire, and garage door opener controls. Low-voltage wiring is generally safer — it can't deliver a lethal shock under normal conditions — and in most jurisdictions doesn't require an electrical permit or a licensed electrician, though local codes vary. However, low-voltage wires still need to be kept separate from line-voltage wires (typically 2" minimum separation in walls) to prevent interference and code violations. An electrician is recommended when low-voltage work intersects with line-voltage systems (e.g., adding a smart thermostat that needs a C-wire pulled from the furnace), when running cable through fire-rated walls or ceilings, or when local code requires a permit.

Question 20

What is a Transfer switch?

Accepted Answer

An electrical device that safely switches a home's power source between the utility grid and a backup generator. Transfer switches are critical because they prevent back-feeding — sending generator power back into utility lines, which can electrocute line workers and damage equipment. There are two main types: manual transfer switches (MTS), where the homeowner physically flips a lever to switch power sources ($500–$1,500 installed), and automatic transfer switches (ATS), which detect a power outage and switch to generator power within seconds without human intervention ($1,500–$4,000 installed). NEC code requires a transfer switch for any permanently installed generator. Even portable generators should use a transfer switch or interlock kit rather than back-feeding through a dryer outlet (which is a code violation and fire hazard). A licensed electrician must install transfer switches because they connect directly to the main electrical panel.

Question 21

What is a Junction box?

Accepted Answer

A metal or plastic enclosure where electrical wires are spliced or connected. The National Electrical Code (NEC) requires every wire splice to be contained inside a junction box — exposed splices are a fire hazard and a code violation. Junction boxes must remain accessible (never buried behind drywall without a cover plate), and the box size must be large enough for the number and gauge of wires it holds (calculated by NEC Article 314.16). Common types: 4" square boxes, octagonal ceiling boxes, and single-gang switch/outlet boxes. A missing cover plate or an overstuffed box with too many wires is a common finding in home inspections. Cost for adding or replacing a junction box: $50–$150 for a standard box; $150–$300 if drywall cutting and patching is needed.

Question 22

What is a Wire gauge?

Accepted Answer

Wire gauge refers to the standardized measurement of electrical wire diameter, expressed in the American Wire Gauge (AWG) system used throughout North America. The AWG scale is counterintuitive: smaller numbers indicate thicker wires with greater current-carrying capacity, while larger numbers indicate thinner wires. For example, 14 AWG wire (commonly used for 15-amp lighting circuits) has a diameter of about 1.63 mm, while 10 AWG wire (used for 30-amp dryer or AC circuits) is approximately 2.59 mm thick. Selecting the correct wire gauge is critical for electrical safety — undersized wire overheats under load, melting insulation and creating a serious fire hazard. The National Electrical Code (NEC) specifies minimum wire gauges for each circuit amperage: 14 AWG for 15-amp circuits, 12 AWG for 20-amp circuits, 10 AWG for 30-amp circuits, 8 AWG for 40-amp circuits, and 6 AWG for 50-amp circuits (such as electric ranges and EV chargers). Wire gauge also affects voltage drop: on long runs (over 50 feet), electricians often upsize the wire by one gauge to keep voltage drop below the recommended 3 percent maximum. Residential wiring overwhelmingly uses copper wire, though aluminum wire (which requires upsizing by two gauge numbers for equivalent ampacity) is still used for large feeder cables and service entrance wiring because it costs 40 to 60 percent less than copper. Wire cost varies by gauge: 14/2 NM-B (Romex) runs about $0.25 to $0.40 per foot, while 6/3 NM-B costs $2.50 to $4.00 per foot. A licensed electrician will calculate the required wire gauge based on circuit amperage, wire length, ambient temperature, and conduit fill when designing or modifying electrical circuits. Using the wrong gauge is a code violation that will fail inspection and, more importantly, can cause overheating, tripped breakers, or electrical fires.

Question 23

What is a Smart home wiring?

Accepted Answer

Smart home wiring refers to the structured cabling and electrical infrastructure needed to support connected devices — smart thermostats, video doorbells, security cameras, automated lighting, and whole-home audio. While many smart devices use Wi-Fi, reliable installations often require dedicated low-voltage wiring (Cat6/Cat6a Ethernet, coaxial, or speaker wire) run to specific locations. Key considerations include a central wiring closet or panel, adequate electrical circuits for PoE (Power over Ethernet) switches, and neutral wires in switch boxes for smart switches (many older homes lack these). An electrician experienced in low-voltage work can plan the cable runs, install structured wiring during a remodel, or retrofit cables in existing walls. Costs range from $500–$2,000 for basic setups (smart thermostat + a few cameras) to $5,000–$15,000+ for whole-home pre-wiring in new construction.

Question 24

What is a Whole-house generator?

Accepted Answer

A whole-house generator (also called a standby generator) is a permanently installed, fuel-powered unit that automatically provides electricity to an entire home when utility power fails. Unlike portable generators that require manual setup and extension cords, standby generators connect directly to the electrical panel through an automatic transfer switch (ATS) that detects the outage and switches to generator power within 10–30 seconds. They run on natural gas or propane (liquid propane models are common where gas service is unavailable) and range from 14 kW for essential circuits to 22–26 kW for powering an entire home including HVAC. Installation costs $7,000–$15,000 for a mid-range unit including the generator ($3,000–$6,000), transfer switch ($500–$1,500), concrete pad, gas line extension, and licensed electrician labor. Annual maintenance — oil change, filter, spark plugs, battery test — runs $200–$500. Key brands include Generac, Kohler, and Briggs & Stratton. A licensed electrician performs the installation and handles the required building permit and utility notification.

Question 25

What is a Romex wire (NM-B cable)?

Accepted Answer

Romex is the popular brand name for NM-B (non-metallic sheathed) cable, the standard wiring used in residential construction throughout North America. It consists of two or more insulated copper conductors plus a bare ground wire, all wrapped in a flat plastic jacket. The jacket is color-coded by wire gauge: white for 14 AWG (15-amp circuits — lighting, general outlets), yellow for 12 AWG (20-amp circuits — kitchen, bathroom, garage outlets), and orange for 10 AWG (30-amp circuits — dryers, water heaters). Romex can be used in dry, interior locations — it is not rated for outdoor, underground, or wet locations (use UF-B cable instead) and cannot be run through conduit in most jurisdictions. NEC code requires Romex to be stapled within 12 inches of every box and every 4.5 feet along its run. Cost is $0.30–$1.00 per foot depending on gauge. Only a licensed electrician should install new Romex runs, as improper installation is a leading cause of residential electrical fires.

Question 26

What is a Wire nut?

Accepted Answer

A twist-on wire connector used to join two or more electrical conductors inside a junction box. Wire nuts consist of a plastic insulating shell with a tapered, threaded metal insert (or spring) that grips the bare wire ends when twisted clockwise. They are color-coded by size: gray (smallest, for #22–#16 wires), blue (#22–#14), orange (#22–#14, fewer conductors), yellow (#18–#12, up to 4 wires), and red (#18–#10, up to 5 wires). Proper technique: strip 5/8 to 3/4 inch of insulation from each wire, hold the stripped ends parallel, and twist the wire nut clockwise until it's snug and no bare copper is visible below the shell. A light tug confirms the connection is secure. Common mistakes that cause electrical fires: using the wrong size (too large = loose connection), reusing old wire nuts, not stripping enough insulation, or twisting counterclockwise. While DIY-friendly for simple connections, any work inside a panel or for new circuits requires a licensed electrician.

Question 27

What is a Level 2 EV charger?

Accepted Answer

A 240-volt electric vehicle charging station that delivers 16–80 amps (typically 32–48A for residential) and adds 20–40 miles of range per hour of charging — roughly 8–12× faster than a standard 120V Level 1 outlet. Most residential Level 2 chargers require a dedicated 40–60 amp circuit on a 240V breaker, using 6-gauge or 8-gauge wiring depending on amperage. Installation costs $500–$2,500 total: the charger unit itself runs $300–$700 (hardwired or NEMA 14-50 plug-in), and the electrical work — running a new circuit from the panel, potentially upgrading the panel if it lacks capacity — adds $200–$1,800. Key considerations: panel capacity (many older homes need a panel upgrade or a smart load-management device), wire run distance (longer runs = thicker gauge = higher cost), outdoor vs. garage placement (outdoor requires a NEMA 4 rated unit and weatherproof outlet), and local permit requirements. Popular brands include ChargePoint, JuiceBox, Grizzl-E, and Tesla Wall Connector. A licensed electrician should handle installation to meet NEC Article 625 requirements and qualify for any utility rebates.

Question 28

What is a Electrical grounding?

Accepted Answer

A safety system that provides a low-resistance path from all metal parts of an electrical installation (outlets, fixtures, appliance frames, panel enclosure) to the earth, so that fault current flows harmlessly into the ground rather than through a person. The NEC requires all 120V and 240V circuits to include an equipment grounding conductor (the bare copper or green wire) connected to a grounding electrode system — typically a copper-clad ground rod (8 feet long, driven into the earth near the panel) bonded to the water pipe where it enters the house. Proper grounding is essential for GFCI and AFCI breakers to function correctly. Signs of grounding problems: tingling when touching metal appliances, GFCI outlets that won't reset, frequent tripped breakers, and a 3-prong outlet tester showing 'open ground.' Upgrading an ungrounded older home (common in pre-1960s houses with two-prong outlets) to full grounding costs $1,500–$4,000 for a typical single-family home — one of the highest-ROI electrical upgrades for both safety and home value.

Households	362,650
Owner-occupied share	39 %
Jobs per year (electrician)	67,588
Pros the market supports	2,171
listed on HireLocal	19
Coverage	0.9 %
Score	100 / 100

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