Outdoor Electrical Parts: How Contractors Pick Gear That Survives Weather, Code, and Real Job Sites

Updated: August 15, 2025

TL;DR
Outdoor installs are wet, corroded, and usually get abused by sun, salt, and lawn crews. Choose parts that are listed for wet locations, match enclosure and cover ratings to the exposure, protect every outdoor outlet with GFCI and in-use covers, and prioritize corrosion resistance. Use wet-rated conductors in wet raceways, UF-B for direct burial, and liquidtight or Schedule 80 PVC where damage is likely. For Suffolk County, NY and other coastal zones, lean toward stainless hardware and NEMA 4X. Build your bill of materials around weatherproof boxes, extra-duty in-use covers, WR/TR GFCI receptacles, PVC or liquidtight raceway, grounding, photocells/timers, landscape transformers, and surge protection. Link choices back to 2023 NEC Articles 110, 210, 300, 310, 314, 406, 410, 411, 242 and OSHA jobsite rules. First stop for parts: weatherproof device/outlet boxes and while-in-use covers.

Why this matters on the job

Outdoor work looks simple until a spring thaw fills your raceways with water and the GFCIs trip all week. Weather beats on everything. Sun cooks plastics. Salt air eats hardware. Mowers hit boxes. If you do not pick the right listings and ratings on day one, you get callbacks. Callbacks erase profit.

Start with the environment. If it is damp or wet, use parts listed for that location. Boxes and covers need the right type rating for rain, hose-down, or corrosion. Outdoor receptacles in wet locations need extra-duty, while-in-use covers and WR/TR devices supported by GFCI protection. In many installs, the inside of the raceway is a wet location, so conductors must be wet-rated. The 2023 NEC draws clear lines on all this, and OSHA adds jobsite rules for temporary power and extension cords. [1][2][3][4][5][6][7]

If you just need the gear list, jump to Parts to stock and related products. You can build most of these jobs with weatherproof box covers, WR/TR GFCI receptacles, liquidtight flexible metal conduit, Schedule 80 PVC conduit, conduit connectors, UF-B cable, and surge protective devices.

Fundamentals

Wet and damp locations
Outdoors is usually damp or wet. Raceways in these areas often count as wet on the inside. That drives your conductor choice and your splicing methods. NEC 2023 treats conductors and boxes differently in wet and damp locations. [1][3][5]

Listings and ratings
Match the part to the conditions. Enclosures and covers carry NEMA type ratings like 3R, 4, and 4X. Use 3R for rain. Use 4 when you need splashing and hose-down. Use 4X for corrosion resistance on the coast. NEMA is clear that IP ratings are not one-to-one with NEMA types. [8][9]

Conductors
If the location is wet, use conductors identified for wet locations. Common picks are THWN-2 and XHHW-2 pulled in raceway. For direct burial, use UF-B. If you need single conductors, Revco stocks THHN/THWN-2 copper building wire and THWN-2 reels. [5]

Boxes and covers
Outdoors, use weatherproof boxes and listed covers. In wet locations, receptacles must have an extra-duty, while-in-use cover with the plug connected. Revco stocks both weatherproof device/outlet boxes and in-use covers. [2][4]

Receptacles
Use receptacles listed WR (weather-resistant) and TR (tamper-resistant) where required, and protect outdoor outlets with GFCI. You can source WR/TR GFCIs and WR receptacles from Revco. [2][6]

Raceways and fittings
Pick raceway for abuse and moisture. Use liquidtight flexible metal conduit for vibration and flex. Use liquidtight flexible nonmetallic where metal is not needed. Where you expect impact, Schedule 80 PVC helps. Use listed liquidtight connectors and conduit connectors. [1][3]

Controls and lighting
Outdoor lighting often needs photocells and timers. Revco carries outdoor occupancy sensors and photocell controls. For landscape zones, use low-voltage transformers and luminaires listed for wet or damp as needed. [10][11]

Surge and grounding
Lightning and switching events beat up outdoor gear. Add a Type 1 or Type 2 SPD at panels serving outdoor loads. Bond metal parts, clamp to grounding electrodes, and use listed clamps and rods like grounding-bonding clamps. [12]

Local reality for Suffolk County, NY
Salt air and storms mean faster corrosion. Favor 316 stainless hardware and NEMA 4X where feasible. Seal penetrations. Keep splices out of splash zones. Schedule inspections after winter.

Code and compliance

• Article 110: Follow listing and labeling and manufacturer instructions. [13]

• Article 300: Underground requirements and wet raceways. The interior of some raceways is a wet location, even above grade in certain conditions. [1][3]

• Article 310: Conductors in wet locations must be identified for wet. THWN-2 and XHHW-2 are common. [5]

• Article 314.15: Boxes in damp or wet locations must be listed and installed to shed water. [4]

• Article 406.9(B): Outdoor receptacles in wet locations need extra-duty in-use covers; receptacles must be WR where required. [2]

• Article 210.8: GFCI protection for outdoor receptacles at dwelling and non-dwelling locations per the listed items. [2]

• Article 410: Luminaires must be listed for damp or wet as applicable. [10]

• Article 411: Low-voltage lighting systems rules. [11]

• Article 242: Surge protection device application and listing. [12]

OSHA jobsite
For temporary power and cords, OSHA requires either GFCI protection or an Assured Equipment Grounding Conductor Program. Keep hands dry when plugging. Inspect cords and use outdoor-rated cord types on site. [6][7]

Selection steps

Step 1: Define the exposure and abuse
Is this damp or wet? Will it see rain or hose-down? Is it coastal with salt spray, like many Suffolk County sites? Is mechanical damage likely? Match NEMA type, cover, and raceway to the worst realistic case. Use weatherproof boxes and NEMA 4/4X where needed. [8][9]

Step 2: Pick the wiring method

• Above grade, in raceway: pull THWN-2 or XHHW-2 in PVC Schedule 80 or liquidtight where flex is needed.

• Direct burial branch circuits: use UF-B and follow NEC depth and protection rules. [1][5]

Step 3: Choose boxes, covers, and devices

• Box: use listed weatherproof models.

• Cover: if the receptacle will be used in the rain, use an extra-duty, in-use cover like these.

• Device: use WR/TR and GFCI where required, such as this WR/TR GFCI. [2][4][6]

Step 4: Pick conduit and fittings

• Runs subject to impact: Schedule 80 PVC.

• Vibration or equipment whips: liquidtight flex with liquidtight connectors.

• General fittings: conduit connectors. [1][3]

Step 5: Plan grounding and surge

• Bond metallic parts. Use grounding clamps and appropriate electrodes.

• For panels feeding outdoor loads, add a Type 1/2 SPD. [12]

Step 6: Add controls

• Photocell or timer on lighting. Use photocell controls or outdoor occupancy sensors. [10]

Step 7: Splicing and terminations

• In wet or direct burial, use sealed, listed connectors. Gel-filled or sealed systems listed to UL 486D prevent water intrusion. [14][15]

Sizing or configuration examples

Example A: Outdoor receptacle on a residence

• Device: 20 A, 125 V receptacle listed WR/TR.

• Protection: GFCI at the device or upstream breaker.

• Box: listed weatherproof with gasket.

• Cover: extra-duty in-use cover.

• Conductors: THWN-2 in PVC since the interior is considered wet.

• Raceway: PVC Schedule 80 near grade.

• Connectors: liquidtight connectors. [2][4][5]

Example B: Garden lighting loop

• System: 12 V landscape lighting.

• Power: low-voltage transformer in a listed enclosure.

• Controls: photocell or timer.

• Cable: listed landscape cable per instructions.

• Connections: gel-filled splices listed for wet locations (UL 486D).

• Surge: SPD at the panel feeding the transformer. [10][11][12][14]

Example C: Pump whip to an outdoor condensing unit

• Conductors: THWN-2.

• Raceway: short length of liquidtight flex to the equipment.

• Fittings: listed liquidtight connectors.

• Disconnect: NEMA 3R enclosure or better depending on exposure. [1][8][9]

Installation and wiring notes

• Follow the listing and instructions. [13]

• Use wet-rated splices. Use sealed connector systems listed to UL 486D in wet or direct burial. [14][15]

• Seal the top of raceways into outdoor enclosures and allow drainage if the instructions say so.

• Support raceways per code and instructions.

• Use stainless or coated hardware in coastal zones.

• Do not mix boxes and covers unless the listing permits it.

• Keep receptacle faces vertical under in-use covers.

• Label GFCI locations and test monthly.

Testing, commissioning, and documentation

• Test GFCIs with the built-in test button.

• Verify polarity and grounding at devices.

• Check enclosure gaskets and cover operation.

• Confirm SPD indicators show protection available.

• Record product model numbers and ratings for turnover.

• Document cord and GFCI checks on jobsites when you use the AEGCP option. [6][7]

Troubleshooting

• GFCI nuisance trips: check for water in boxes, cords laying in puddles, or shared neutrals wired wrong on line/load. Use in-use covers and wet-rated splices. [2]

• Corrosion: upgrade to NEMA 4X and stainless hardware. Add drip loops. [8][9]

• Lighting cycles at dusk/dawn: re-aim or relocate photocell.

• Pump trips breaker: verify conductor size, check for water in the whip, meg the motor.

• Landscape lights dim: undersized cable or long runs; split runs and use proper transformer taps.

FAQ

Do I really need an in-use cover if the receptacle has a weatherproof cover?
If the receptacle is in a wet location and will be used while it is raining, the extra-duty, while-in-use cover is required by 406.9(B). [2]

Can I run THHN outdoors?
THHN alone is not identified for wet locations. Use THWN-2 or XHHW-2 in wet raceways. Many spools are dual-rated THHN/THWN-2. Check the marking. [5]
Revco stocks THHN/THWN-2 copper and THWN-2 reels.

What NEMA type is “good enough” outside?
3R is rainproof. 4 is watertight against splashing and hose-down. 4X adds corrosion resistance. On Long Island near the shore, 4X is often worth it. [8][9]

Can I use standard wirenuts in a lamppost base?
Not if it is wet. Use UL 486D listed sealed connectors or gel-filled kits per the instructions. [14][15]

Do outdoor receptacles always need GFCI?
Most outdoor receptacles do under NEC 210.8. Check the exceptions in your occupancy. On construction sites, OSHA also requires GFCI or an AEGCP for cords and temporary power. [2][6]

Common mistakes to avoid

• Using indoor boxes and covers outside.

• Skipping WR/TR on receptacles.

• Forgetting the raceway interior may be wet, then pulling dry-location wire.

• Using unsealed wirenuts in wet boxes.

• Choosing NEMA 1 or 3R where washdown happens.

• Ignoring surge protection on controls and lighting.

• Forgetting extra-duty in-use covers on outlets that power pumps and lawn gear.

For compliant parts, browse weatherproof boxes, covers, and conduit/connectors at Revco.

When to call the AHJ or engineer of record

• You are near a pool, spa, fountain, or marina.

• You are unsure if a location is damp vs wet.

• You need confirmation on burial depths, sleeves, or backfill.

• You are navigating flood zones or coastal corrosion issues.

• You are adding controls to life-safety systems.

Disclaimer

Always verify requirements with your Authority Having Jurisdiction and the current manufacturer instructions before you order or install.

Credits

• Author: Revco Editorial Team — Electrical Content Editor — 12 years supporting commercial and residential outdoor installations across Long Island.

• Contact: [email protected] | (631) 283-3600

About Revco Lighting & Electrical Supply

“Since 1978, Revco Lighting & Electrical Supply has been helping professionals bring their projects to light—literally. As a go-to source for lighting and electrical products across Long Island, NY and nearby areas, we specialize in supporting contractors, builders, and industry experts with practical solutions and dependable service. Whether it’s a complex commercial build or a simple residential upgrade, we’re here to make sure you have what you need, when you need it.”

Sources

[1] NFPA — “Electrical installation requirements: Article 300” — https://www.nfpa.org/News-and-Research/Publications-and-media/NFPA-Journal/2025/Spring-2025/Features/Electrical-installation-requirements (retrieved 08/2025).
[2] NFPA/Leviton — Weather-Resistant and Tamper-Resistant receptacles; NEC 406.9(B) in-use covers and GFCI context — https://hvaccofficecdn.com/upload/hosted/content/_userNAS-extensions_/0HRf_1587480892172.pdf; https://www.leviton.com/en/pages/captain-code-2023 (retrieved 08/2025). OSHA
[3] Mike Holt — Chapter 3 Wiring Methods (300.9 wet raceways), conductors in wet locations — https://mikeholt.com/download.php?file=PDF/Chapter_3-Sample.pdf (retrieved 08/2025).
[4] Electrical License Renewal — Boxes in damp or wet locations (314.15) — https://www.electricallrc.com/nec-314-15-boxes-in-damp-or-wet-locations/ (retrieved 08/2025).
[5] Mike Holt — Conductor rules (310.10(C) wet) — see [3].
[6] eCFR — OSHA 29 CFR 1926 Subpart K; GFCI or AEGCP on construction sites — https://www.ecfr.gov/current/title-29/subtitle-B/chapter-XVII/part-1926/subpart-K (retrieved 08/2025).
[7] OSHA — Electrical safety notes; 1910.334 wet handling and safeguards — https://www.osha.gov/etools/hospitals/hospital-wide-hazards/electrical-safety (retrieved 08/2025).
[8] NEMA — Enclosure types overview — https://www.nema.org/standards/view/types-of-industrial-enclosures (retrieved 08/2025).
[9] NEMA Bulletin 10250 — Enclosure types and selection guide; plus note on IP mapping limits — https://www.nema.org/docs/default-source/standards-document-library/10250r12018reaffirmed2021e876e721-ae26-42e3-9fde-3d2bc6931e5d.pdf and Kele IP comparison note https://assets.kele.com/productassets/specifications/kele/ip_comp_chart.pdf (retrieved 08/2025).
[10] UL Solutions — UL 1598 Luminaires, wet/damp markings — https://www.ul.com/resources/ul-1598-standard-luminaires (retrieved 08/2025).
[11] IAEI — Article 411 low-voltage lighting summary — https://iaeimagazine.org/magazine/2020/november2020/low-voltage-lighting-systems-and-the-nec/ (retrieved 08/2025).
[12] NFPA — Article 242 (SPD) overview — see [1].
[13] NFPA — 110.3(B) follow listing and labeling; general installation principles — see [1].
[14] UL — UL 486D Sealed Wire Connector Systems (scope) — https://www.shopulstandards.com/ProductDetail.aspx?UniqueKey=45471 (retrieved 08/2025).
[15] 3M and IDEAL — Gel-filled connector data (moisture-resistant, listed for wet) — https://multimedia.3m.com/mws/media/136854O/3m-scotchlok-idc-connector-314.pdf; https://www.idealind.com/content/dam/electrical/product-categories/wire-connectors/twist-on/weatherproof/resources/WeatherProof%20WireConnector%20SpecSheet.pdf (retrieved 08/2025).