DRSA LED Lighting Company

Dock Lighting Calculator

12VDC piling cap calculator for Single Color and Color Changing RGBW systems.

1. Dock Information
2. Enter Piling Cap Sizes
Single Color amp range: 8" = 0.7A, 20" = 1.6A.
8" Cap0.7A
8.5" Cap0.74A
9" Cap0.77A
9.5" Cap0.81A
10" Cap0.85A
10.5" Cap0.89A
11" Cap0.93A
11.5" Cap0.96A
12" Cap1A
12.5" Cap1.04A
13" Cap1.07A
13.5" Cap1.11A
14" Cap1.15A
14.5" Cap1.19A
15" Cap1.23A
15.5" Cap1.26A
16" Cap1.3A
16.5" Cap1.34A
17" Cap1.38A
17.5" Cap1.41A
18" Cap1.45A
18.5" Cap1.49A
19" Cap1.53A
19.5" Cap1.56A
20" Cap1.6A
3. System Results
Lighting TypeSingle Color
Total Caps0
Total Amps0.00 A
Total Watts0.0 W
Recommended Zones2
Approx. Amps Per Zone0.00 A
Power Supply Per Zone120W @ 12V
Recommended Main Wire10 AWG
Dock Layout Recommendation

Recommended: center feed. Can be powered from one end, but larger wire may be required due to voltage drop.

Estimated longest one-way run: 50 ft
Electrical Box Placement

Install the power supply box above the waterline, under the dock or on the inside of a piling, protected from direct spray, and accessible for service.

  • Use a weatherproof enclosure.
  • Keep box accessible for service.
  • GFCI protect the AC feed.
  • Use tinned stranded marine copper.
  • For RGBW, allow room for receiver/controller wiring.
Dock Layout Visual Guide

Straight Dock

Recommended: center feed. Can be powered from one end, but larger wire may be needed.

T Dock

Power from the main trunk, then split left and right at the top.

U Dock

Treat as three sections: left side, back section, and right side.

L Dock

Best box location is the inside corner where the two sections meet.

Reference Wire Chart — 12VDC Main Trunk

Planning guide only. Final wire size should be verified based on exact routing, fixture specs, and site conditions.

Current25 ft50 ft75 ft100 ft150 ft200 ft
5A12 AWG10 AWG8 AWG6 AWG4 AWG2 AWG
10A10 AWG8 AWG6 AWG6 AWG4 AWG2 AWG
15A8 AWG6 AWG4 AWG4 AWG2 AWG1/0 AWG
20A6 AWG4 AWG2 AWG2 AWG1/0 AWG2/0 AWG
25A4 AWG4 AWG2 AWG1/0 AWG2/0 AWG3/0 AWG
30A4 AWG2 AWG1/0 AWG2/0 AWG3/0 AWG4/0 AWG
40A2 AWG1/0 AWG2/0 AWG3/0 AWG4/0 AWGReview Design

This calculator is for planning and estimating only. Final system design should be verified based on actual fixture specifications, exact wire routing, local electrical code, and site conditions.