New Boatbuilders Home Page - Electrical Table Wire Size

ELECTRICAL TABLE ALLOWABLE AMPERAGE OF CONDUCTORS FOR UNDER 50 VOLTS

The following table is used to calculate the appropriate wire size based on the temperature of the insulation of the wire.

Note: This is the table that is in the Federal Regulations. ABYC Standard E-11 has Five seperate tables based on how many conductors are in a wire bundle.

To return to the previous page close this page

Table 1 - ALLOWABLE AMPERAGE OF CONDUCTORS FOR SYSTEMS UNDER 50 VOLTS
Temperature Rating of Conductor Insulation
Conductor Size English (metric)	60 C (149 F)		75 C (167 F)		80 C (176 F)		90 C (194 F)		105 C (221 F)		125 C (257 F)		200 C (392 F)
Conductor Size English (metric)	Outside Engine space	Inside Engine Space	Outside Engine space	Inside Engine Space	Outside Engine space	Inside Engine Space	Outside Engine space	Inside Engine Space	Outside Engine space	Inside Engine Space	Outside Engine space	Inside Engine Space	Outside or Inside Engine Space
18 (0.8)	10	5.8	10	7.5	15	11.7	20	16.4	20	17.0	25	22.3	25
16 (1)	15	8.7	15	11.3	20	15.6	25	20.5	25	21.3	30	25.7	35
14 (2)	20	11.6	20	15.0	25	19.5	30	24.6	35	29.8	40	35.6	45
12 (3)	25	14.5	25	18.8	35	27.3	40	32.8	45	38.3	50	44.5	55
10 (5)	40	23.2	40	30.0	50	39.0	55	45.1	60	51.0	70	62.3	70
8 (8)	55	31.9	65	48.8	70	54.6	70	57.4	80	68.0	90	80.1	100
6 (13)	80	46.4	95	71.3	100	78.0	100	82.0	120	102	125	111	135
4 (19)	105	60.9	125	93.8	130	101	135	110	160	136	170	151	180
2 (32)	140	81.2	170	127	175	138	180	147	210	178	225	200	240
1 (40)	165	95.7	195	146	210	163	210	172	245	208	265	235	280
0 (50)	195	113	230	172	245	191	245	200	285	242	305	271	325
00 (62)	225	130	265	198	285	222	285	233	330	280	355	316	370
000 (81)	260	150	310	232	330	257	330	270	385	327	410	384	430
0000 (103)	300	174	380	270	385	300	385	315	445	378	475	422	510

Notes for the above table
Temperature Rating of Conductor Insulation
	60^oC (140^oF)	75^oC (167^oF)	80^oC (176^oF)	90^oC (194^oF)	105^oC (221^oF)	125^oC (257^oF)	200^oC (392^oF)
1. See the following table: Temperature Rating of conductor	0.58	0.75	0.78	0.82	0.85	0.89	1.00
2. See the following Table: Number of current carrying conductors							Correction Factor
3							0.70
4 to 6							0.60
7 to 24							0.50
25 and above							0.40

<<Back Next>>

This Web site may contain copyrighted material the use of which has not always been specifically authorized by the copyright owner. I am making such material available in my efforts to advance understanding of educational, economic, and scientific issues, etc. I believe this constitutes a "fair use" of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this Web site is distributed without profit to those who have expressed a prior interest in receiving the included information for nonprofit educational purposes. For more information see: www.law.cornell.edu/uscode/17/107.shtml. If you wish to use copyrighted material from this Web site for purposes of your own that go beyond "fair use", you must obtain permission from the copyright owner.