Electrical Systems - Voltage Drop
Page 5
This page contains a large chart which is best viewed on a PC or Tablet. To view on a mobile device turn if sideways to landscape, or scroll to the right to see the entire table.
Electrical regulations and standards that apply to boat builders and recreational boats. Calculating Voltage Drop .
This table is from ABYC standards. There are tables for 24 volts and 32 volts, and for AC systems, in the ABYC Electrical Standard E-11. Contact ABYC for a copy of E-11, AC and DC Electrical Systems on Boats.
Table to determine wire size due to voltage drop based on the length of the wire. This table is for 12 volts only.
Length of conductor from power source to the device and back to the power source |
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Feet | 10 | 15 | 20 | 25 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | 110 | 120 | 130 | 140 | 150 | 160 | 170 |
Total Amps | 12 volt - 10% drop wire sizes gauge | ||||||||||||||||||
5 | 18 | 18 | 18 | 18 | 18 | 16 | 16 | 14 | 14 | 14 | 12 | 12 | 12 | 12 | 12 | 10 | 10 | 10 | 10 |
10 | 18 | 18 | 16 | 16 | 14 | 14 | 12 | 12 | 10 | 10 | 10 | 10 | 8 | 8 | 8 | 8 | 8 | 8 | 6 |
15 | 18 | 16 | 14 | 14 | 12 | 12 | 10 | 10 | 8 | 8 | 8 | 8 | 8 | 6 | 6 | 6 | 6 | 6 | 6 |
20 | 16 | 14 | 14 | 12 | 12 | 10 | 10 | 8 | 8 | 8 | 6 | 6 | 6 | 6 | 6 | 4 | 4 | 4 | 4 |
25 | 16 | 14 | 12 | 12 | 10 | 10 | 8 | 8 | 8 | 6 | 6 | 6 | 6 | 4 | 4 | 4 | 4 | 4 | 2 |
30 | 14 | 12 | 12 | 10 | 10 | 8 | 8 | 6 | 6 | 6 | 6 | 4 | 4 | 4 | 4 | 2 | 2 | 2 | 2 |
40 | 14 | 12 | 10 | 10 | 8 | 8 | 6 | 6 | 6 | 4 | 4 | 4 | 2 | 2 | 2 | 2 | 2 | 2 | 2 |
50 | 12 | 10 | 10 | 8 | 8 | 6 | 6 | 4 | 4 | 4 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 1 |
60 | 12 | 10 | 8 | 8 | 6 | 6 | 4 | 4 | 2 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 0 | 0 | 0 |
70 | 10 | 8 | 8 | 6 | 6 | 6 | 4 | 2 | 2 | 2 | 2 | 1 | 1 | 1 | 0 | 0 | 0 | 2/0 | 2/0 |
80 | 10 | 8 | 8 | 6 | 6 | 4 | 4 | 2 | 2 | 2 | 1 | 1 | 0 | 0 | 0 | 2/0 | 2/0 | 2/0 | 2/0 |
90 | 10 | 8 | 6 | 6 | 6 | 4 | 2 | 2 | 2 | 1 | 1 | 0 | 0 | 0 | 2/0 | 2/0 | 2/0 | 3/0 | 3/0 |
100 | 10 | 8 | 6 | 6 | 4 | 4 | 2 | 2 | 1 | 1 | 0 | 0 | 0 | 2/0 | 2/0 | 2/0 | 2/0 | 3/0 | 3/0 |