APPENDIX 63
ancorproducts.com
Conductors Sized (AWG) for 10% Voltage Drop
10% Voltage Drop at 12 Volts
Current (Amps)
Length
5 10 15 20 25 30 40 50 60 70 80 90 100
10' 3m 18 18 18 16 16 14 14 12 12 10 10 10 10 15' 5m1818161414121210108 8 8 8 20' 6m18161414121210108 8 8 6 6 25' 8m181614121210108 8 6 6 6 6 30' 9m1814121210108 8 6 6 6 6 4 40' 12m16141210108 8 6 6 6 4 4 4 50' 15m161210108 8 6 6 4 4 4 2 2 60' 18m1412108866442222 70' 21m141088666422221 80' 24m141088664422211 90' 27m121086664222111/0 100' 30m12108 6 6 4 4 2 2 1 1 1/01/0 110' 33m12 8 8 6 6 4 2 2 2 1 1/01/01/0 120' 36m12 8 6 6 4 4 2 2 1 1 1/01/02/0 130' 40m12 8 6 6 4 4 2 2 1 1/01/02/02/0 140' 43m10 8 6 6 4 2 2 1 1 1/02/02/02/0 150' 46m10 8 6 4 4 2 2 1 1/0 1/0 2/0 2/0 3/0 160' 49m10 8 6 4 4 2 2 1 1/0 2/0 2/0 3/0 3/0 170' 52m10 6 6 4 2 2 2 1 1/0 2/0 2/0 3/0 3/0
Use 10% voltage drop for any “non-critical” applications: windlass, cabin lights, etc....
For Example... Q: A bilge pump draws 10 amps. The positive run is 11 feet from the power panel, including the float switch. The negative run is only 10 feet. What size is the wire? A: Use the formula to reach the correct answer:
10% Voltage Drop at 24 Volts
10.75 x 10 (amps) x 21 (total length of run) 0.36 (3% of 12V)
Current (Amps)
= 6,271
CM =
Length
5 10 15 20 25 30 40 50 60 70 80 90 100
10' 3m 18 18 18 18 18 18 16 16 14 14 14 12 12 15' 5m 18 18 18 18 16 16 14 14 12 12 12 10 10 20' 6m 18 18 18 16 16 14 14 12 12 10 10 10 10 25' 8m18181616141412121010108 8 30' 9m1818161414121210108 8 8 8 40' 12m18161414121210108 8 8 6 6 50' 15m181614121210108 8 6 6 6 6 60' 18m1814121210108 8 6 6 6 6 4 70' 21m16141210108 8 6 6 6 6 4 4 80' 24m16141210108 8 6 6 6 4 4 4 90' 27m161210108 8 6 6 6 4 4 4 2 100' 30m161210108 8 6 6 4 4 4 2 2 110' 33m1412108886644222 120' 36m1412108866442222 130' 40m1412108866442222 140' 43m141088666422221 150' 46m141088664422221 160' 49m141088664422211 170' 52m121086664222211
Ancor cable specifications show that 12 AWG wire has a CM area of 6,500 and is the correct choice. However, SAE wire has a CM area of only 5,833. Under NFPA and USCG regulations, 10 SAE wire must be used.
TECH TIP
ABYC Recommends… “Conductors used for lighting, other than navigation lights, and other circuits where voltage drop is not critical, shall be sized for a voltage drop not to exceed 10 percent.” ABYC 11.16.1.2.7.
10% Voltage Drop at 32 Volts
Current (Amps)
Length
5 10 15 20 25 30 40 50 60 70 80 90 100
10' 3m 18 18 18 18 18 18 18 16 16 14 14 14 14 15' 5m 18 18 18 18 18 18 16 14 14 14 12 12 12 20' 6m 18 18 18 18 16 16 14 14 12 12 12 10 10 25' 8m 18 18 18 16 16 14 14 12 12 10 10 10 10 30' 9m1818181614141214101010108 40' 12m1818161414121210108 8 8 8 50' 15m18161414121210108 8 8 6 6 60' 18m181614121210108 8 8 6 6 6 70' 21m1814141210108 8 8 6 6 6 6 80' 24m1814121210108 8 6 6 6 6 4 90' 27m1814121010108 6 6 6 6 4 4 100' 30m16141210108 8 6 6 6 4 4 4 110' 33m16141210108 8 6 6 6 4 4 4 120' 36m161210108 8 6 6 6 4 4 4 2 130' 40m161210108 8 6 6 6 4 4 2 2 140' 43m1412108886644222 150' 46m1412108866644222 160' 49m1412108866442222 170' 52m1412108866442222
Powered by FlippingBook