Do You Need a Permit for Solar Panels?
Short answer: yes, in 99% of US jurisdictions. Solar installations require building + electrical permits (plus sometimes structural), and a separate utility interconnection agreement. This guide covers SolarAPP+ fast-track permitting, NEC 690 and 706, fire setbacks, battery storage rules, and the 28 states with HOA solar access protection.
The Short Answer
You need a building permit (structural load, fire setbacks), an electrical permit (NEC 690), and — separately from the building permit — a utility interconnection agreement. Battery storage adds NEC 706 and its own permit. SolarAPP+ fast-tracks approval in 150+ jurisdictions. 28 states have HOA solar access laws that prevent HOAs from banning rooftop solar.
When You DO Need a Solar Permit
Any Rooftop PV System
Every grid-tied rooftop PV system requires a building permit (for the structural attachment and fire setbacks) and an electrical permit (for the wiring, inverter, and disconnect). This applies whether the system is 2 kW or 15 kW, and whether installed by a contractor or DIY.
Any Ground-Mount System
Ground-mount systems need a building permit for the racking foundation (concrete footings or driven piles), an electrical permit for the conduit run to the house, and often an accessory structure permit. Setback rules apply.
Battery Storage Systems
Any battery (Tesla Powerwall, Enphase, LG, etc.) requires a separate permit under NEC Article 706. This is in addition to the PV permit. Location, clearances, and ventilation are strictly regulated.
Off-Grid PV Systems
Off-grid systems still need building and electrical permits. Some jurisdictions waive the interconnection agreement since there is no grid tie, but the NEC and IRC requirements still apply.
System Expansion / Panel Additions
Adding panels to an existing system usually triggers a new permit. The updated system may require a different inverter, new rapid shutdown equipment, or updated structural calculations.
Inverter Replacement
Replacing an inverter — especially swapping a string inverter for microinverters or adding power optimizers — is an electrical modification requiring a permit.
Roof-Integrated Solar (BIPV / Solar Shingles)
Solar shingles (Tesla Solar Roof, GAF Energy, etc.) require building and electrical permits for both the roof replacement and the solar portion. May require structural review because the solar becomes part of the roof load.
When You DON'T Need a Solar Permit
The exemption list is extremely narrow:
Very small portable/plug-in solar panels for charging devices or small battery banks
Solar-powered landscape lighting (no grid connection, no permanent wiring)
Solar chargers / trickle chargers not tied to building electrical
Temporary event solar (portable generators, RV setups)
Solar Permit Requirements by State (2026)
All 50 states require permits for grid-tied solar. The key differentiator is HOA solar access protection — 28 states have statutes preventing HOAs from banning rooftop solar.
| State | Permit Required | HOA Solar Protection | Typical Fee |
|---|---|---|---|
| Alabama | Yes | No | $200–$600 |
| Alaska | Yes | No | $250–$700 |
| Arizona | Yes | Yes (ARS 33-1816) | $250–$700 |
| Arkansas | Yes | No | $150–$500 |
| California | Yes | Yes (Civil Code 714) | $300–$1,000 |
| Colorado | Yes | Yes (CRS 38-30-168) | $200–$700 |
| Connecticut | Yes | Yes (Gen Stat 47-280) | $250–$700 |
| Delaware | Yes | Yes (25 Del C § 318) | $200–$600 |
| Florida | Yes | Yes (FS 163.04) | $250–$800 |
| Georgia | Yes | No | $200–$600 |
| Hawaii | Yes | Yes (HRS 196-8.5) | $300–$800 |
| Idaho | Yes | No | $200–$600 |
| Illinois | Yes | Yes (765 ILCS 165) | $250–$700 |
| Indiana | Yes | No | $200–$600 |
| Iowa | Yes | No | $200–$600 |
| Kansas | Yes | No | $200–$500 |
| Kentucky | Yes | No | $200–$600 |
| Louisiana | Yes | Yes (La RS 9:1255) | $250–$700 |
| Maine | Yes | Yes (33 MRS § 1422) | $200–$600 |
| Maryland | Yes | Yes (RP § 2-119) | $250–$700 |
| Massachusetts | Yes | Yes (MGL c.184) | $250–$800 |
| Michigan | Yes | No | $200–$600 |
| Minnesota | Yes | Yes (Stat 500.30) | $250–$700 |
| Mississippi | Yes | No | $200–$500 |
| Missouri | Yes | Yes (Rev Stat 442.404) | $200–$600 |
| Montana | Yes | No | $200–$500 |
| Nebraska | Yes | No | $200–$500 |
| Nevada | Yes | Yes (NRS 116.2055) | $250–$700 |
| New Hampshire | Yes | No | $200–$600 |
| New Jersey | Yes | Yes (NJSA 45:22A-48.2) | $300–$800 |
| New Mexico | Yes | Yes (NMSA 47-3-12) | $200–$600 |
| New York | Yes | Yes (Real Prop Law 335-b) | $300–$1,000 |
| North Carolina | Yes | Yes (GS 22B-20) | $200–$700 |
| North Dakota | Yes | No | $200–$500 |
| Ohio | Yes | No | $200–$600 |
| Oklahoma | Yes | No | $200–$500 |
| Oregon | Yes | Yes (ORS 105.880) | $250–$700 |
| Pennsylvania | Yes | No | $200–$600 |
| Rhode Island | Yes | Yes (RIGL 34-36.1-5) | $200–$600 |
| South Carolina | Yes | No | $200–$600 |
| South Dakota | Yes | No | $200–$500 |
| Tennessee | Yes | No | $200–$600 |
| Texas | Yes | Yes (Prop Code 202.010) | $200–$800 |
| Utah | Yes | No | $200–$600 |
| Vermont | Yes | Yes (27 VSA § 544) | $200–$600 |
| Virginia | Yes | Yes (VA Code 67-701) | $250–$700 |
| Washington | Yes | Yes (RCW 64.38.055) | $250–$700 |
| West Virginia | Yes | No | $200–$500 |
| Wisconsin | Yes | Yes (Stat 236.292) | $200–$600 |
| Wyoming | Yes | No | $200–$500 |
Alabama
Building + electrical permits required. No statewide HOA solar access law.
Alaska
Solar uncommon due to latitude but permitted where installed.
Arizona
ARS 33-1816 prohibits HOAs from banning solar. SolarAPP+ available in Phoenix, Tucson.
Arkansas
Building + electrical permits required; no HOA solar rights law.
California
Title 24 solar mandate on new homes. SolarAPP+ adoption leader. Fire setbacks per CBC Chapter 11B-3111.
Colorado
SolarAPP+ in Denver metro. HOA solar access protected by statute.
Connecticut
HOA solar protections; each of 169 towns permits separately.
Delaware
HOA solar access protected by statute.
Florida
FS 163.04 prohibits HOA solar bans. SolarAPP+ in several FL jurisdictions. Wind zone review critical.
Georgia
No statewide HOA solar protection. Atlanta and suburbs enforce IRC/NEC.
Sources: State solar rights statutes, NREL SolarAPP+ adoption database, IRC R324, NEC 690/705/706. Accessed April 2026.
SolarAPP+ Fast-Track Permitting
SolarAPP+ (Solar Automated Permit Processing Plus) is a free online permitting tool developed by the National Renewable Energy Laboratory (NREL) and funded by the US Department of Energy. It automates the residential solar permit process by running code-compliance checks in real time.
Instant Permit Issuance
For code-compliant systems, SolarAPP+ issues a valid permit within minutes — not weeks. The tool checks system size, structural requirements, electrical design, and fire setbacks automatically.
150+ Adopting Jurisdictions (2026)
Major adopters include much of Arizona (Phoenix, Tucson, Scottsdale), California (Fresno, Pleasant Hill, Stockton), Colorado (Denver metro), Washington (Seattle, Tacoma), and parts of Florida, Texas, and New York. New jurisdictions are added monthly.
What SolarAPP+ Covers
Residential rooftop PV systems up to 38.4 kW (AC), with or without battery storage, using UL-listed equipment from an approved database. Does not cover ground-mount, commercial, or non-standard installations.
Contractor-Only Portal
SolarAPP+ is designed for contractors to use on behalf of homeowners. It streamlines but does not eliminate the need for a licensed installer in most jurisdictions. Fees are paid through the jurisdiction's portal at application.
What It Does NOT Replace
SolarAPP+ does NOT replace the utility interconnection agreement — that is still a separate process with your utility. It also does not replace HOA approval where required.
Interconnection vs. Building Permit
One of the most commonly misunderstood parts of solar permitting: the utility interconnection agreement is a separate approval from the city building permit. You need BOTH.
Building / Electrical Permit
Issued by: City or County Building Department
- • Structural load review
- • Fire setbacks (IRC R324)
- • NEC 690 electrical compliance
- • Rapid shutdown equipment
- • Inverter and disconnect location
- • Grounding and bonding
Interconnection Agreement
Issued by: Your Utility Company
- • Net metering eligibility
- • Anti-islanding protection (IEEE 1547)
- • Bi-directional meter install
- • Utility-side service upgrades
- • Production cap compliance
- • Permission to Operate (PTO)
You cannot legally turn on your solar system until BOTH approvals are complete. Many homeowners are surprised when their panels are installed and wired but the system remains off for weeks awaiting Permission to Operate (PTO) from the utility. The average PTO wait is 2–8 weeks after installation, though some utilities take 3+ months.
NEC Article 690 — Solar PV Systems
NEC Article 690 is the main electrical code section for residential and commercial solar. Key 2020/2023 NEC requirements:
NEC 690.12 — Rapid Shutdown
All rooftop PV systems must have a rapid shutdown system that de-energizes conductors in the array within 30 seconds of activation. Inside-array conductors must drop to 30V or less within 30 seconds. Protects firefighters responding to a house fire.
NEC 690.13 — PV System Disconnect
A disconnect must be readily accessible — typically on the outside of the building near the service entrance or on the inverter. Must be clearly labeled.
NEC 690.31 — Wiring Methods
Covers allowable conductors, conduit, and cable types. Most residential installs use THWN-2 in EMT or MC cable. PV wire (USE-2) allowed within the array area.
NEC 690.41 — Grounding
PV modules and racking must be grounded. Most modern racking systems are UL 2703 listed and provide integrated grounding.
NEC 690.47 — Grounding Electrode System
The PV system must tie into the existing building grounding electrode system.
NEC 705 — Interconnected Electric Power Production Sources
Governs the connection point of the PV system to the home's electrical service. The "120% rule" (NEC 705.12) limits how much PV can be back-fed into a panel based on main breaker size.
Labeling
NEC requires extensive labeling at the inverter, disconnect, main panel, and meter — warning labels, system information labels, and emergency shutdown labels. Missing labels is one of the most common inspection failures.
Structural Load Review
Solar panels add about 3–5 pounds per square foot of distributed dead load to the roof. For most roofs built in the last 30 years, this is well within the design margin. For older roofs or high-snow areas, a structural review may be required.
Load Calculations
Installer calculates added dead load from panels + racking, combined with existing roof dead load, snow load (per ASCE 7), and wind load. Must verify the existing roof framing can support the combined load per IRC R802.
When a PE Stamp is Required
California requires PE stamps on any install where the existing roof load capacity cannot be clearly verified. New York City, Boston, and many other major cities require stamps for all residential solar. Older roofs (pre-1970) or unusual framing also typically require review.
Point Load vs Distributed Load
The panel mount points (typically every 48") create point loads on individual rafters. Engineers verify that each rafter can handle both the shared distributed load and the concentrated point loads at the mounts.
Wind Uplift
Wind can create uplift forces that try to lift panels off the roof. IRC R301.2 design wind speeds determine how much uplift the racking must resist. Hurricane zones (Florida, Gulf Coast, Atlantic coast) have the most stringent requirements.
Snow Load
In heavy-snow areas (Northeast, Upper Midwest, Rocky Mountains), panels can accumulate snow just like the roof. ASCE 7 snow load must be verified for the combined roof + panel assembly.
Roof-Mount vs. Ground-Mount
Roof-Mount
- • Building + electrical permits
- • Structural load review
- • IRC R324 fire setback compliance
- • Typical permit fee: $200–$600
- • SolarAPP+ eligible
- • Roof flashing and waterproofing
Ground-Mount
- • Building + electrical + accessory permits
- • Foundation/footing inspection
- • Zoning setbacks apply
- • Typical permit fee: $300–$1,000
- • NOT SolarAPP+ eligible
- • Conduit burial depth (NEC 300.5)
- • May need conditional use permit if large
Battery Storage Permits (NEC 706)
Adding a battery (Tesla Powerwall, Enphase IQ Battery, LG Chem, FranklinWH, etc.) adds an entire new permit scope under NEC Article 706 — Energy Storage Systems.
Installation Location
Batteries can be installed in a garage (with proper fire separation), outdoors in a weather-rated enclosure, or in a dedicated room. NOT typically allowed in bedrooms, living rooms, kitchens, or closets. Must be accessible for maintenance.
Clearances
Minimum 3 ft clearance in front of the battery for maintenance access. Setback from doors and windows per NFPA 855 and local fire code (varies — typically 3 ft from operable openings).
UL 9540 / UL 9540A Listing
All residential battery systems must be UL 9540 listed. UL 9540A thermal runaway testing is increasingly required in California and other wildfire-prone areas.
Total kWh Limits
NFPA 855 and local fire codes limit total residential battery storage — typically 20 kWh per zone without additional safeguards, up to 80 kWh total with separation. California Title 24 has additional residential limits.
Fire Detection
Some jurisdictions require a dedicated smoke detector or heat detector near the battery, interfaced with the home alarm system. Lithium-ion thermal runaway events produce characteristic smoke patterns that dedicated sensors can detect.
Ventilation
Lithium-ion batteries don't typically require active ventilation (unlike older lead-acid), but the installation area must meet minimum air volume requirements and not be "hot-boxed" (ambient temperature above 105–110°F).
Fire Setbacks (IRC R324 / CA Title 24)
IRC R324 (2018 and later) and California Title 24 require minimum roof pathways for firefighter access. These setbacks significantly reduce usable roof area.
Ridge Pathway
Minimum 36" pathway along the ridge, free of panels. Allows firefighters to ventilate the attic during a fire.
Eave-to-Ridge Pathway
At least one 36" pathway from the eave to the ridge on each roof plane, unless the plane is too small.
Hip and Valley Setbacks
Panels must be set back 18 inches from hips and valleys in many jurisdictions (36" in California single-family).
Smoke Ventilation Area
California requires a smoke ventilation zone at the top of each roof plane for fire department access.
Small Roof Exemption
Roofs smaller than certain thresholds (e.g., less than 600 sq ft of roof plane) may be exempt from the pathway requirements. Check local amendments.
Impact on System Size
Fire setbacks typically reduce usable roof area by 15–30%, sometimes making the difference between whether a home can host a meaningful system. Some installers add panels on secondary roof planes to compensate.
HOA Solar Access Laws (28 States)
28 states have statutes that prevent HOAs from banning rooftop solar outright. In these states, HOAs can still regulate aesthetics (color, placement, screening) but cannot prohibit solar or impose restrictions that significantly reduce system efficiency or increase cost.
States With HOA Solar Access Protection
Arizona, California, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Louisiana, Maine, Maryland, Massachusetts, Minnesota, Missouri, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Rhode Island, Texas, Vermont, Virginia, Washington, Wisconsin, plus a few others with narrower protections.
Example statutes: CA Civil Code 714, AZ ARS 33-1816, FL FS 163.04, TX Prop Code 202.010, CO CRS 38-30-168.
States Without HOA Solar Protection
Alabama, Alaska, Arkansas, Georgia, Idaho, Indiana, Iowa, Kansas, Kentucky, Michigan, Mississippi, Montana, Nebraska, New Hampshire, North Dakota, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Utah, West Virginia, Wyoming.
In these states, HOAs can ban rooftop solar entirely if their CC&Rs allow it. Always check HOA documents before signing a solar contract.
Typical Solar Permit Costs
$0–$100
SolarAPP+ jurisdictions
(fast-track)
$200–$500
Standard rooftop
(building + elec)
$400–$800
Rooftop + battery
$600–$1,500
Ground-mount or
CA/NY/NJ
How to Get a Solar Permit
Choose a licensed solar contractor
Most jurisdictions require a licensed C-46/C-10 solar contractor (or equivalent) to pull solar permits. DIY is permitted in very few places. The contractor handles the entire permit package.
Site assessment and system design
Contractor surveys your roof, runs shading analysis, sizes the system based on usage, and creates structural and electrical drawings.
Check SolarAPP+ availability
If your jurisdiction is on the SolarAPP+ list, your contractor can submit through that portal for near-instant approval.
Submit building + electrical permit
Includes site plan, structural calculations, electrical one-line diagram, equipment spec sheets, and fire setback diagram. Typical fee: $200–$800.
Apply for utility interconnection
Submit the interconnection application to your utility (separate from the building permit). This step can take 2–8 weeks for review.
Installation after both approvals
Building permit must be approved before work begins. Utility approval (Authorization to Construct) must also be received.
Building inspection + utility PTO
The building department inspects the completed install. After passing, the utility issues Permission to Operate (PTO), which is when you can legally turn the system on.
Key Code References
NEC 2023 Article 690 — Solar Photovoltaic (PV) Systems
The primary electrical code for solar. Covers wiring, disconnects, grounding, rapid shutdown (690.12), and labeling.
NEC 2023 Article 705 — Interconnected Electric Power Production Sources
Governs how the PV system connects to the utility grid. Contains the "120% rule" (705.12) for back-feeding main panels.
NEC 2023 Article 706 — Energy Storage Systems
Governs battery storage systems. Installation location, disconnects, clearances, and fire safety.
IRC 2021 Section R324 — Solar Energy Systems
Building code section for residential solar. Covers structural, fire setback, and rooftop pathway requirements.
CA Title 24 / CBC Chapter 11B-3111
California-specific solar requirements: fire setbacks, structural review, and the 2020 residential solar mandate on new homes.
IEEE 1547-2018 — Interconnection Standard
The utility interconnection standard. Covers anti-islanding, voltage/frequency ride-through, and grid support functions.
NFPA 855 — Standard for Installation of Stationary Energy Storage Systems
Fire code standard for residential and commercial battery storage. Location, separation, and quantity limits.
UL 9540 / UL 9540A
Safety listing standards for energy storage systems and thermal runaway fire testing.
Consequences of Skipping the Permit
No Utility Interconnection
Utilities will not allow grid connection without an approved building permit. An unpermitted system cannot legally back-feed power or participate in net metering.
Lost State Incentives and Utility Rebates
State tax credits, utility rebates, and net metering programs almost universally require a permitted, interconnected system. An unpermitted install disqualifies you from these — often a $2,000–$8,000 swing depending on your state (the residential federal Section 25D credit itself expired 12/31/2025, so that specific loss no longer applies in 2026).
Fines: $500–$10,000+
Solar-related code violations carry significant fines. Retroactive permits cost 2–3x normal fees and may require partial system removal to verify compliance.
Fire Risk + Insurance Denial
Improper solar installs are a leading cause of rooftop fires. Insurance companies routinely deny fire claims on unpermitted solar installations.
Home Sale Complications
Unpermitted solar is a major flag during home sales. Buyers, inspectors, and lenders all scrutinize solar systems, and unpermitted systems often kill sales or require expensive remediation.
Firefighter Safety Risk
Without inspected rapid shutdown and fire setbacks, responders face electrocution hazards during a structure fire. This is one of the most serious safety issues in residential solar.
Frequently Asked Questions
Do I need a permit to install solar panels?
Yes — in 99% of US jurisdictions. Solar panel installations require at minimum a building permit (for structural load and fire setbacks) and an electrical permit (under NEC Article 690). Ground-mount systems also require a site permit. Battery storage adds NEC Article 706 compliance and its own permit. Additionally, a utility interconnection agreement is required before the system can be turned on — this is separate from the city building permit.
What is SolarAPP+?
SolarAPP+ (Solar Automated Permit Processing Plus) is a free online tool developed by the National Renewable Energy Laboratory (NREL) that instantly issues residential rooftop solar permits for code-compliant systems. As of 2026, SolarAPP+ is adopted in 150+ jurisdictions across the US, including parts of Arizona, California, Colorado, Texas, and Washington. When available, it reduces permit wait times from weeks to minutes.
What is the difference between a building permit and an interconnection agreement?
A building permit is issued by your city or county building department and covers structural load, fire setbacks, and electrical work. An interconnection agreement is issued by your utility company (not your city) and covers the technical requirements for tying your solar system into the grid — including net metering, anti-islanding protection, and utility-side equipment. Both are required, and they are independent processes. You can have your building permit approved and still wait weeks or months for utility interconnection.
What NEC sections apply to residential solar?
NEC Article 690 covers Solar Photovoltaic (PV) systems — including wiring methods, grounding, disconnects, labeling, and rapid shutdown (NEC 690.12). NEC Article 705 covers interconnection to the utility grid. NEC Article 706 covers energy storage systems (batteries). NEC 2020 and 2023 both require rapid shutdown systems on all new residential solar installs — a feature that de-energizes the panels within 30 seconds of activation to protect firefighters.
Do I need a structural engineer for solar panels?
Usually no for a typical rooftop install. Most permit offices accept the solar contractor's structural load calculations using published racking/mount specs. However, certain situations require a licensed structural engineer stamp: older roofs, homes with questionable framing, ground-mount systems in high-wind or heavy-snow zones, or any system over a certain kW threshold. California requires engineering stamps for any roof whose existing design cannot clearly support the added load.
Can a ground-mount solar array skip the building permit?
No — ground-mount systems typically require MORE permits than rooftop, not fewer. A ground-mount array needs a building permit (for the racking foundation), an electrical permit (for the conduit run from the array to the house), and often a separate accessory structure permit. Setback rules apply the same as for sheds. Large ground-mount systems (over 10 kW) may also require a zoning variance or conditional use permit.
Do solar batteries need a separate permit?
Yes. Battery storage systems are regulated by NEC Article 706 and must be permitted separately from the PV array. Key requirements include: installation location (garage with fire separation, outdoor enclosure, or dedicated room), clearance from doors and windows, ventilation, labeling, disconnect means, and in some jurisdictions a dedicated smoke detector or fire alarm interface. Lithium-ion batteries over certain kWh thresholds may require a Hazardous Materials permit in some cities.
What are fire setback requirements for rooftop solar?
IRC R324 and most state fire codes require minimum pathways on the roof for firefighter access: typically a 36-inch pathway along the ridge, a 36-inch access pathway from the eave to the ridge, and 18–36" setbacks from hips and valleys. California Title 24 has additional residential solar fire setback requirements. These can significantly reduce the usable roof area, sometimes cutting system size by 15–30%.
Do HOAs have to allow solar panels?
28 states have "solar access" or "solar rights" laws that prohibit HOAs from banning rooftop solar outright. These include AZ, CA, CO, CT, DE, FL, HI, IL, LA, ME, MD, MA, MN, MO, NV, NJ, NM, NY, NC, OR, RI, TX, VT, VA, WA, WI, and a few others. However, HOAs in these states can still regulate aesthetics — panel color, placement, or requiring screening from the street — as long as the regulations don't significantly reduce system efficiency or increase cost. In the 22 remaining states, HOAs can prohibit solar entirely unless the CC&Rs allow it.
How much does a solar permit cost?
Residential solar permit fees typically run $200 to $800 depending on the jurisdiction, with California, New York, and New Jersey at the high end. Some cities use a flat fee ($150–$400), others use a valuation-based fee (1–3% of system cost), and a few charge per-panel fees. SolarAPP+ jurisdictions often have reduced or waived fees. Commercial solar permits are significantly more expensive.
What is net metering and how does it relate to permits?
Net metering is a utility billing arrangement where excess solar energy you send to the grid credits against energy you pull from the grid. It is administered by your utility, not the building department. You apply for net metering AFTER your system is built and permitted — typically through the utility interconnection process. Net metering policy varies dramatically by state (full retail credit in some, much lower in others like California's NEM 3.0).
What happens if I install solar without a permit?
Consequences are significant: fines ($500–$10,000+), the utility will refuse to interconnect (meaning you cannot legally operate the system or benefit from net metering), insurance claim denial if the unpermitted install causes a fire, forced removal at homeowner expense, and major home sale complications. Note on federal tax credits: the residential Section 25D credit expired December 31, 2025 under the One Big Beautiful Bill Act — owner-financed residential solar placed in service in 2026 and later receives no federal credit. State incentives, utility rebates, and net metering still apply and often require a permitted, interconnected system.
Related Permit Guides & Tools
This guide is informational and was last updated April 2026. Solar, electrical, and fire codes are updated frequently. Always verify current requirements with your local building department and utility. Solar installations should be performed by licensed C-46/C-10 solar contractors. This is not legal, electrical, or engineering advice.