RV Pedestal Wire Sizing Service Guide
// PLAN 30 A AND 50 A CAMPSITE PEDESTALS, CAMPGROUND FEEDERS, DEMAND FACTORS, GROUNDING, AND LONG-RUN VOLTAGE DROP BEFORE TRENCHING OR PANEL WORK. //
RV sites look like simple receptacles until the same feeder serves many pedestals across 150 to 600 ft of trench. Use this guide to connect the calculator inputs to NEC 551, NEC 210, NEC 215, NEC 250, NEC 310, and IEC 60364 checks so electricians, engineers, and serious DIY planners can separate ampacity, demand, voltage drop, grounding, and equipment listing before buying wire.
50 A pedestal
A NEMA 14-50 RV receptacle is a 120/240 V, 3-pole, 4-wire outlet, so neutral and equipment grounding conductors must be planned correctly
Voltage-drop target
Use about 3% for the final branch circuit and 5% total feeder plus branch unless the owner or IEC 60364-5-52 limit is stricter
Demand planning
NEC 551 demand factors can reduce feeder load for multiple sites, but individual pedestal conductors still match the receptacle and breaker rating
TL;DR
- Start with receptacle rating, site count, voltage, phase, and one-way route length
- Treat a 50 A RV pedestal as a 120/240 V four-wire load with neutral and grounding separated
- Use NEC 551 demand factors for campground feeders, not for undersizing one pedestal circuit
- Upsize long runs when voltage drop approaches 3% on the branch or 5% total
- Check GFCI, weatherproof equipment, grounding, bonding, and local AHJ rules before energizing
Core definitions
RV pedestal
An RV pedestal is listed site equipment that provides receptacles, breakers, and weatherproof connection points for a recreational vehicle
Demand factor
A demand factor is a code-permitted multiplier used to estimate diversified load when many RV sites are supplied by one feeder
Voltage drop
Voltage drop is the voltage lost in conductors under load and is checked separately from ampacity and breaker size
Sizing workflow
1. Define each site
Record 20 A, 30 A, and 50 A receptacles, breaker ratings, voltage, neutral needs, pedestal listing, and whether sites are grouped on a loop feeder
2. Calculate load
Use NEC 551.73 for RV site feeder and service demand where adopted, then keep each pedestal branch matched to its overcurrent device and receptacle
3. Select conductors
Use NEC Table 310.16, terminal limits from 110.14(C), adjustment factors, copper or aluminum material, insulation rating, and equipment listing
4. Run voltage drop
Enter one-way distance, current, material, voltage, and phase. A 50 A site at 180 ft often moves from 6 AWG copper toward 4 AWG copper for performance
5. Finish protection review
Verify GFCI requirements, weatherproof enclosures, equipment grounding conductor, neutral isolation, bonding, burial depth, raceway fill, and AHJ notes
Practical examples
30 A travel trailer site
30 A at 120 V, 75 ft one-way copper branch circuit, TT-30 receptacle, THWN-2 in PVC
10 AWG copper is a common starting point for ampacity, but voltage drop is about 2.8% at 30 A, so longer runs may justify 8 AWG
50 A RV pedestal near panel
50 A at 120/240 V, 60 ft one-way copper run, NEMA 14-50 receptacle, four-wire circuit
6 AWG copper commonly satisfies ampacity, and voltage drop is usually under 2% when terminals and derating allow it
50 A pedestal at far site
50 A at 120/240 V, 180 ft one-way copper run, campground branch circuit
6 AWG copper can exceed a 3% design target, while 4 AWG copper brings the drop closer to 2.6% before final derating checks
Twelve-site feeder
Twelve 50 A sites on a 120/240 V single-phase feeder, diversified under NEC 551.73, longest branch 240 ft
The feeder may use demand factors, but each branch and pedestal still needs conductor ampacity, grounding, neutral, and voltage-drop review
Common RV pedestal sizing checks
| Pedestal or feeder | Load basis | Common conductor starting point | Voltage-drop trigger | Design note |
|---|---|---|---|---|
| 20 A convenience outlet | 20 A at 120 V | 12 AWG copper | Check above 75 ft | Often GFCI protected and weather resistant |
| 30 A RV site | 30 A at 120 V | 10 AWG copper | Check above 75 ft | TT-30 is not a 240 V receptacle |
| 50 A RV site | 50 A at 120/240 V | 6 AWG copper | Check above 100 ft | Four-wire circuit with neutral and EGC |
| Long 50 A branch | 50 A at 180 ft | 4 AWG copper often considered | Voltage drop governs | Confirm lug size and conduit fill |
| Multi-site feeder | NEC 551.73 demand load | Engineer copper or aluminum feeder | Check farthest pedestal | Demand factor does not replace branch sizing |
NEC and IEC references
This guide is not a substitute for the adopted code or AHJ decision. It shows how calculator inputs relate to public references for NFPA 70, IEC 60364, IEC 60309 connectors, and NEMA connector configurations.
NEC 551
Article 551 covers recreational vehicles, RV parks, site supply equipment, receptacle arrangements, and demand factors for feeders and services
NEC 210 and 215
Branch-circuit and feeder conductors must coordinate with overcurrent protection, continuous load assumptions, and voltage-drop design notes
NEC 250 and 310
Grounding, bonding, equipment grounding conductors, ampacity tables, adjustment factors, and terminal temperature limits decide the usable installation
IEC 60364-7-708
IEC projects for caravan parks and similar locations coordinate socket outlets, protective devices, earthing, cable sizing, and voltage drop under IEC 60364-5-52
Field checklist before trenching
- Confirm pedestal listing, receptacle type, breaker rating, and whether the site is 120 V or 120/240 V
- Measure the actual one-way route including sweeps, risers, panel offsets, and spare conduit paths
- Check conductor material, insulation type, terminal temperature rating, and aluminum compatibility where used
- Apply feeder demand factors only where the adopted NEC article and AHJ allow them
- Verify neutral isolation, equipment grounding conductor size, bonding, GFCI protection, and weatherproof covers
- Document voltage drop at the farthest loaded pedestal before ordering wire
RV pedestal wire sizing FAQ
Is a 50 A RV pedestal 120 V or 240 V?
A 50 A RV pedestal using NEMA 14-50 is 120/240 V with two hot conductors, one neutral, and one equipment grounding conductor
Can I use 10 AWG for a 30 A RV pedestal?
10 AWG copper is a common ampacity starting point for a 30 A circuit, but a 100 ft 120 V run may need 8 AWG to control voltage drop
Can feeder demand factors reduce branch wire size?
No. NEC 551.73 demand can size feeders or services for multiple sites, but each pedestal branch still matches the breaker, receptacle, and installation conditions
What voltage drop should I use for a campground?
Many designers use 3% branch and 5% total as NEC-style targets, while IEC designs document the Clause 525 or project-specific voltage-drop limit
Should DIYers install RV pedestals themselves?
A single pedestal may involve 50 A power, trenching, GFCI, grounding, and permits, so DIYers should use this guide to prepare questions for a licensed electrician
Size the RV circuit with the calculator
Use the main wire gauge calculator for the branch or feeder current, then verify voltage drop and ampacity before trenching, pulling conductors, or landing the pedestal.