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APPENDIX B

Electric Data

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Table B-2. Conductor insulation

Trade Name	Type Letter	Temperature Rating	Application Provisions
Rubber-covered fixture wire (solid or 7-strand)	*RF-1	60°C 140°F	Fixture wiring, limited to 300 V
	*RF-2	60°C 140°F	Fixture wiring
Rubber-covered fixture wire (flexible stranding)	*FF-1	60°C 140°F	Fixture wiring limited to 300 V
	*FF-2	60°C 140°F	Fixture wiring
Heat- resistant, rubber-covered fixture wire (solid or 7-strand)	*RFH-1	75°C 167°F	Fixture wiring, limited to 300 V
	*RFH-2	75°C 167°F	Fixture wiring
Heat- resistant, rubber- covered fixture wire (flexible stranding)	*FFH-1	75°C 167°F	Fixture wiring, limited to 300 V
	*FFH-2	75°C 167°F	Fixture wiring
Thermoplastic-covered fixture wire (solid or stranded)	*TF	60°C 140°F	Fixture wiring
Thermoplastic- covered fixture wire (flexible stranding)	*TFF	60°C 140°F	Fixture wiring
Cotton- covered, heat- resistant fixture wire	*CF	90°C 194°F	Fixture wiring, limited to 300 V
Asbestos-covered, heat- resistant fixture wire	*AF	150°C 302°F	Fixture wiring, limited to 300 V and dry indoor locations
Silicone, rubber-insulated fixture wire (solid or 7-strand)	*SF-1	200°C 392°F	Fixture wiring, limited to 300 V
	*SF-2	200°C 392°F	Fixture wiring
Silicone, rubber-insulated fixture wire (flexible stranding)	*SFF-1	150°C 302°F	Fixture wiring, limited to 300 V
	*SFF-2	150°C 302°F	Fixture wiring
Code rubber	R	60°C 140°F	Dry locations
Heat- resistant rubber	RH	75°C 167°F	Dry locations
	RHH	90°C 194°F	Dry locations
Moisture- resistant rubber	RW	60°C 140°F	Dry and wet locations; for over 2,000 V, insulation shall be ozone-resistant.
Moisture- and heat- resistant rubber	RH-RW	60°C 140°F	Dry and wet locations; for over 2,000 V, insulation shall be ozone-resistant.
		75°C 167°F	Dry locations
Thermoplastic and fibrous outer braid	TBS	90°C 194°F	Switchboard wiring only
Synthetic heat- resistant	SIS	90°C 194°F	Switchboard wiring only
Mineral insulation (metal sheathed)	MI	85°C 185°F	Dry and wet locations with Type O termination fittings, maximum operating temperature for special applications 250°C
Silicone-asbestos	SA	90°C 194°F	Dry locations, maximum operating temperature for special applications 125°C
Fluorinated ethylene propylene	FEP	90°C 194°F	Dry locations
	FEPB	200°C 392°F	Dry locations--special applications
		75°C 167°F	For over 2,000 V, insulation shall be ozone-resistant.
Moisture- and heat-resistant rubber	RHW	75°C 167°F	Dry and wet locations; for over 2,000 V, insulation shall be ozone-resistant
Latex rubber	RU	60°C 140°F	Dry locations
Heat-resistant latex rubber	RUH	75°C 167°F	Dry locations
Moisture- resistant latex rubber	RUW	60°C 140°F	Dry and wet locations
Thermoplastic	T	60°C 140°F	Dry locations
Moisture- resistant thermoplastic	TW	60°C 140°F	Dry and wet locations
Heat-resistant thermoplastic	THHN	90°C 194°F	Dry locations
Moisture- and heat-resistant thermoplastic	THW	75°C 167°F	Dry and wet locations
	THWN	75°C 167°F	Dry and wet locations
Thermoplastic and asbestos varnished cambric	TA	90°C 194°F	Switchboard wiring only
	V	85°C 185°F	Dry locations only, smaller than No 6 by special permission
Asbestos and varnished cambric	AVA	110°C 230°F	Dry locations
	AVL	110°C 230°F	Dry and wet locations
	AVB	90°C 194°F	Dry locations
Asbestos	A	200°C 392°F	Dry locations only; in raceways, only for loads to or within apparatus; limited to 300 V
	AA	200°C 392°F	Dry locations only; open wiring; in raceways, only for loads to or within apparatus; limited to 300 V
	AI	125°C 257°F	Dry locations only; in raceways, only for loads to or within apparatus; limited to 300 V
	AIA	125°C 257°F	Dry locations only; open wiring; in raceways, only for loads to or within apparatus
Paper		85°C 185°F	For underground service conductors or by special permission
*Fixture wires are not intended for installation as branch circuit conductors nor for the connection of portable or stationary appliances.

Table B-3. Allowable current-carrying capacity of copper conductors--not more than three conductors in raceway or cable

Size		Temperature Rating of Conductor1
AWG or MCM		60°C (140°F)	75°C (167°F)	85-90°C (185°F)	110°C (230°F)	125°C (257°F)	200°C (392°F)
14		15	15	252	30	30	30
12		20	20	302	35	40	40
10		30	30	402	45	50	55
8		40	45	50	60	65	70
6		55	65	70	80	85	95
4		70	85	90	105	115	120
3		80	100	105	120	130	145
2		95	115	120	135	145	165
1		110	130	140	160	170	190
1/0		125	150	155	190	200	225
2/0		145	175	185	215	230	250
3/0		165	200	210	245	265	285
4/0		195	230	235	275	310	340
250		215	255	270	315	335	--
300		240	285	300	345	380	--
350		260	310	325	390	420	--
400		280	335	360	420	450	--
500		320	380	405	470	500	--
600		355	420	455	525	545	--
700		385	460	490	560	600	--
750		400	475	500	580	620	--
800		410	490	515	600	640	--
900		435	520	555	--	--	--
1,000		455	545	585	680	730	--
1,250		495	590	645	--	--	--
1,500		520	625	700	785	--	--
1,750		545	650	735	--	--	--
2,000		560	665	775	840	--	--
°C	°F	Correction Factors, Room Temperatures Over 30°C (86°F)
40	104	0.82	0.88	0.90	0.94	0.95	--
45	113	0.71	0.82	0.85	0.90	0.92	--
50	122	0.58	0.75	0.80	0.87	0.89	--
55	131	0.41	0.67	0.74	0.83	0.86	--
60	140	--	0.58	0.67	0.79	0.83	0.91
70	158	--	0.35	0.52	0.71	0.76	0.87
75	167	--	--	0.43	0.66	0.72	0.86
80	176	--	--	0.30	0.61	0.69	0.84
90	194	--	--	--	0.50	0.61	0.80
100	212	--	--	--	--	0.51	0.77
120	248	--	--	--	--	--	0.69
140	284	--	--	--	--	--	0.50
1Current capacities relate to conductors in Table B-2. See Table B-2 for the temperature rating of the conductor. 2Current capacities for types FEP, FEPB, PHH, and THHN conductors for sizes AWG 14, 12, and 10 shall be the same as designated for 75°C conductors in this table.

Table B-4. Allowable current-carrying capacity of copper conductors in free air

Size		Temperature Rating of Conductor1
AWG or MCM		60°C (140°F)	75°C (167°F)	85-90°C (185°F)	110°C (230°F)	125°C (257°F)	200°C (392°F)	Bare and Covered Conductor
14		20	20	302	40	40	45	30
12		25	25	402	50	50	55	40
10		40	40	552	65	70	75	55
8		55	65	70	85	90	100	70
6		80	95	100	120	125	135	100
4		105	125	135	160	170	180	130
3		120	145	155	180	195	210	150
2		140	170	180	210	225	240	175
1		165	195	210	245	265	280	205
1/0		195	230	245	285	305	325	235
2/0		225	265	285	330	355	370	275
3/0		260	310	330	385	410	430	320
4/0		300	360	385	445	475	510	370
250		340	405	425	495	530	--	410
300		375	445	480	555	590	--	460
350		420	505	530	610	655	--	510
400		455	545	575	665	710	--	555
500		515	620	660	765	815	--	630
600		575	690	740	855	910	--	710
700		630	755	815	940	1,005	--	780
750		655	785	845	980	1,045	--	810
800		680	815	880	1,020	1,085	--	845
900		730	870	940	--	--	--	905
1,000		780	935	1,000	1,165	1,240	--	965
1,250		890	1,065	1,130	--	--	--	--
1,500		980	1,175	1,260	1,450	--	--	1,215
1,750		1,070	1,280	1,370	--	--	--	--
2,000		1,155	1,385	1,470	1,715	--	--	1,405
°C	°F	Correction Factors, Room Temperatures Over 30°C (86°F)
40	104	0.82	0.88	0.90	0.94	0.95	--	--
45	113	0.71	0.82	0.85	0.90	0.92	--	--
50	122	0.58	0.75	0.80	0.87	0.89	--	--
55	131	0.41	0.67	0.74	0.83	0.86	--	--
60	140	--	0.58	0.67	0.79	0.83	0.91	--
70	158	--	0.35	0.52	0.71	0.76	0.87	--
75	167	--	--	0.43	0.66	0.72	0.86	--
80	176	--	--	0.30	0.61	0.69	0.84	--
90	194	--	--	--	0.50	0.61	0.80	--
100	212	--	--	--	--	0.51	0.77	--
120	248	--	--	--	--	--	0.69	--
140	284	--	--	--	--	--	0.50	--
1Current capacities relate to conductors in Table B-2. See Table B-2 for the temperature rating of the conductor. 2Current capacities for types FEP, FEPB, PHH, and THHN conductors for sizes AWG 14, 12, and 10 shall be the same as designated for 75°C conductors in this table.

Table B-5. Allowable current-carrying capacity of aluminum conductors--not more than three conductors in raceway or cable

Size		Temperature Rating of Conductor1
AWG or MCM		60°C (140°F)	75°C (167°F)	85-90°C (185°F)	110°C (230°F)	125°C (257°F)	200°C (392°F)
12		15	15	252	30	30	30
10		25	25	302	35	40	45
8		30	40	402	45	50	55
6		40	50	55	60	65	75
4		55	65	70	80	90	95
3		65	75	80	95	100	115
23		75	90	95	105	115	130
13		85	100	110	125	135	150
1/03		100	120	125	150	160	180
2/03		115	135	145	170	180	200
3/03		130	155	165	195	210	225
4/03		155	180	185	215	245	270
250		170	205	215	250	270	190
300		190	230	240	275	305	--
350		210	250	260	310	335	--
400		225	270	290	335	360	--
500		260	310	330	380	405	--
600		285	340	370	425	440	--
700		310	375	395	455	485	--
750		320	385	405	470	500	--
800		330	395	415	485	520	--
900		355	425	455	--	--	--
1,000		375	445	480	560	600	--
1,250		405	485	530	--	--	--
1,500		435	520	580	650	--	--
1,750		455	545	615	--	--	--
2,000		470	560	650	705	--	--
°C	°F	Correction Factors, Room Temperatures Over 30°C (86°F)
40	104	0.82	0.88	0.90	0.94	0.95	--
45	113	0.71	0.82	0.85	0.90	0.92	--
50	122	0.58	0.75	0.80	0.87	0.89	--
55	131	0.41	0.67	0.74	0.83	0.86	--
60	140	--	0.58	0.67	0.79	0.83	0.91
70	158	--	0.35	0.52	0.71	0.76	0.87
75	167	--	--	0.43	0.66	0.72	0.86
80	176	--	--	0.30	0.61	0.69	0.84
90	194	--	--	--	0.50	0.61	0.80
100	212	--	--	--	--	0.51	0.77
120	248	--	--	--	--	--	0.69
140	284	--	--	--	--	--	0.50
1Current capacities relate to conductors in Table B-2. See Table B-2 for the temperature rating of the conductor. 2Current capacities for types FEP, FEPB, PHH, and THHN conductors for sizes AWG 14, 12, and 10 shall be the same as designated for 75°C conductors in this table. 3For three-wire, single-phase service and subservice circuits, the allowable current capacity of RH, RH-RW, RHH, RHW, and THW aluminum conductors shall be for sizes No 2-100 amp, No 1-110 amp, No 1/0-125 amp, No 2/0-50 amp, No 3/0-170 amp, and No 4/0-200 amp.

Table B-6. Allowable current-carrying capacity of aluminum conductors in free air

Size		Temperature Rating of Conductor1
AWG or MCM		60°C (140°F)	75°C (167°F)	85-90°C (185°F)	110°C (230°F)	125°C (257°F)	200°C (392°F)	Bare and Covered Conductor
12		20	20	302	40	40	45	30
10		30	30	452	50	55	60	45
8		45	55	552	65	70	80	55
6		60	75	80	95	100	105	80
4		80	100	105	125	135	140	100
3		95	115	120	140	150	165	115
2		110	135	140	165	175	185	135
1		130	155	165	190	205	220	160
1/0		150	180	190	220	240	255	185
2/0		175	210	220	255	275	290	215
3/0		200	240	255	300	320	335	250
4/0		230	280	300	345	370	400	290
250		265	315	330	385	415	--	320
300		290	350	375	435	460	--	360
350		330	395	415	475	510	--	400
400		355	425	450	520	555	--	435
500		405	485	515	595	635	--	490
600		455	545	585	675	720	--	560
700		500	595	645	745	795	--	615
750		515	620	670	775	825	--	640
800		535	645	695	805	855	--	670
900		580	700	750	--	--	--	725
1,000		625	750	800	930	990	--	770
1,250		710	855	905	--	--	--	--
1,500		795	950	1,020	1,175	--	--	985
1,750		875	1,050	1,125	--	--	--	--
2,000		960	1,150	1,220	1,425	--	--	1,165
°C	°F	Correction Factors, Room Temperatures Over 30°C (86°F)
40	104	0.82	0.88	0.90	0.94	0.95	--	--
45	113	0.71	0.82	0.85	0.90	0.92	--	--
50	122	0.58	0.75	0.80	0.87	0.89	--	--
55	131	0.41	0.67	0.74	0.83	0.86	--	--
60	140	--	0.58	0.67	0.79	0.83	0.91	--
70	158	--	0.35	0.52	0.71	0.76	0.87	--
75	167	--	--	0.43	0.66	0.72	0.86	--
80	176	--	--	0.30	0.61	0.69	0.84	--
90	194	--	--	--	0.50	0.61	0.80	--
100	212	--	--	--	--	0.51	0.77	--
120	248	--	--	--	--	--	0.69	--
140	284	--	--	--	--	--	0.50	--
1Current capacities relate to conductors in Table B-2. See Table B-2 for the temperature rating of the conductor. 2Current capacities for types FEP, FEPB, PHH, and THHN conductors for sizes AWG 14, 12, and 10 shall be the same as designated for 75°C conductors in this table.

Table B-7. Reduction of current-carrying capacity for more than three conductors in raceway or cable

Number of Conductors	Percent Reduction of Table B-3 and Table B-5
4 to 6	80
7 to 24	70
25 to 42	60
43 and above	50

Table B-8. Flexible cords

Trade Name	Type Letter	AWG	No of Conductors	Insulation	Braid on Each Conductor	Outer Covering	Use
Parallel tinsel cord	TP	27	2	Rubber	None	Rubber	Attached to an appliance	Damp places	Not hard usage
	TPT	27	2	Thermoplastic	None	Thermoplastic	Attached to an appliance	Damp places	Not hard usage
Jacketed tinsel cord	TS	27	2 or 3	Rubber	None	Rubber	Attached to an appliance	Damp places	Not hard usage
	TST	27	2 or 3	Thermoplastic	None	Thermoplastic	Attached to an appliance	Damp places	Not hard usage
Asbestos- covered, heat- resistant cord	AFC	18-10	2 or 3	Impregnated asbestos	Cotton or rayon	None	Pendant	Dry places	Not hard usage
	AFPO	18-10	2	Impregnated asbestos	Cotton or rayon	Cotton, rayon, or saturated asbestos	Pendant	Dry places	Not hard usage
	AFPD	18-10	2 or 3	Impregnated asbestos	None	Cotton, rayon, or saturated asbestos	Pendant	Dry places	Not hard usage
Cotton- covered, heat- resistant cord	CFC	18-10	2 or 3	Impregnated cotton	Cotton or rayon	None	Pendant	Dry places	Not hard usage
	CFPO	18-10	2	Impregnated cotton	Cotton or rayon	Cotton or rayon	Pendant	Dry places	Not hard usage
	CFPD	18-10	2 or 3	Impregnated cotton	None	Cotton or rayon	Pendant	Dry places	Not hard usage
Parallel cord	PO-1	18	2	Rubber	Cotton	Cotton or rayon	Pendant or portable	Dry places	Not hard usage
	PO-2	18-16	2	Rubber	Cotton	Cotton or rayon	Pendant or portable	Dry places	Not hard usage
	PO	18-10	2	Rubber	Cotton	Cotton or rayon	Pendant or portable	Dry places	Not hard usage
All-rubber parallel cord	SP-1	18	2	Rubber	None	Rubber	Pendant or portable	Damp places	Not hard usage
	SP-2	18-16	2	Rubber	None	Rubber	Pendant or portable	Damp places	Not hard usage
	SP-3	18-10	2	Rubber	None	Rubber	Refrigerators or room air conditioners	Damp places	Not hard usage
All-plastic parallel cord	SPT-1	18	2	Thermoplastic	None	Thermoplastic	Pendant or portable	Damp places	Not hard usage
	SPT-2	18-16	2	Thermoplastic	None	Thermoplastic	Pendant or portable	Damp places	Not hard usage
	SPT-3	18-10	2	Thermoplastic	None	Thermoplastic	Refrigerators or room air conditioners	Damp places	Not hard usage
Lamp cord	C	18-10	2 or more	Rubber	Cotton	None	Pendant or portable	Dry places	Not hard usage
Twisted, portable cord	PD	18-10	2 or more	Rubber	Cotton	Cotton or rayon	Pendant or portable	Dry places	Not hard usage
Reinforced cord	P-1	18	2 or more	Rubber	Cotton	Cotton over rubber filler	Pendant or portable	Dry places	Not hard usage
	P-2	18-16	2 or more	Rubber	Cotton	Cotton over rubber filler	Pendant or portable	Dry places	Not hard usage
	P	18-10	2 or more	Rubber	Cotton	Cotton over rubber filler	Pendant or portable	Dry places	Hard usage
Braided, heavy-duty cord	K	18-10	2 or more	Rubber	Cotton	Two-cotton, moisture- resistant finish	Pendant or portable	Damp places	Hard usage
Vacuum- cleaner cord	SV, SVO	18	2	Rubber	None	Rubber	Pendant or portable	Damp places	Not hard usage
	SVT, SVTO	18	2	Thermoplastic	None	Thermoplastic	Pendant or portable	Damp places	Not hard usage
Junior hard- service cord	SJ	18-16	2, 3 or 4	Rubber	None	Rubber	Pendant or portable	Damp places	Hard usage
	SJO	18-16	2, 3 or 4	Rubber	None	Oil-resistant compound	Pendant or portable	Damp places	Hard usage
	SJT, SJTO	18-16	2, 3 or 4	Thermoplastic or rubber	None	Thermoplastic	Pendant or portable	Damp places	Hard usage
Hard- service cord	S	18-2	2 or more	Rubber	None	Rubber	Pendant or portable	Damp places	Extra hard usage
	SO	18-2	2 or more	Rubber	None	Oil-resistant compound	Pendant or portable	Damp places	Extra hard usage
	ST	18-2	2 or more	Thermoplastic or rubber	None	Thermoplastic	Pendant or portable	Damp places	Extra hard usage
	STO	18-2	2 or more	Thermoplastic or rubber	None	Oil-resistant thermoplastic	Pendant or portable	Damp places	Extra hard usage
Rubber- jacketed, heat- resistant cord	AFSJ	18-16	2 or 3	Impregnated asbestos	None	Rubber	Portable	Damp places	Portable heaters
	AFS	18-16-14	2 or 3	Impregnated asbestos	None	Rubber	Portable	Damp places	Portable heaters
Heater cord	HC	18-12	2, 3, or 4	Rubber and asbestos	Cotton	None	Portable	Dry places	Portable heaters
	HPD	18-12	2, 3, or 4	Rubber with asbestos or all neoprene	None	Cotton or rayon	Portable	Dry places	Portable heaters
Rubber- jacketed heater cord	HSJ	18-16	2, 3, or 4	Rubber with asbestos or all neoprene	None	Cotton and rubber	Portable	Damp places	Portable heaters
Jacketed heater cord	HSJO	18-16	2, 3, or 4	Rubber with asbestos or all neoprene	None	Cotton and oil-resistant compound	Portable	Damp places	Portable heaters
	HS	14-12	2, 3, or 4	Rubber with asbestos or all neoprene	None	Cotton and rubber or neoprene	Portable	Damp places	Portable heaters
	HSO	14-12	2, 3, or 4	Rubber with asbestos or all neoprene	None	Cotton and oil-resistant compound	Portable	Damp places	Portable heaters
Parallel heater cord	HPN	18-16	2	Thermosetting	None	Thermosetting	Portable	Damp places	Portable heaters
Heat- and moisture- resistant cord	AVPO	18-10	2	Asbestos and varnished cambric	None	Asbestos, flame- retardant, moisture- resistant	Pendant or portable	Damp places	Not hard usage
	AVPD	18-10	2 or 3	Asbestos and varnished cambric	None	Asbestos, flame- retardant, moisture- resistant	Pendant or portable	Damp places	Not hard usage
Range, dryer cable	SRD	10-4	3 or 4	Rubber	None	Rubber or neoprene	Portable	Damp places	Ranges, dryers
	SRDT	10-4	3 or 4	Thermoplastic	None	Thermoplastic	Portable	Damp places	Ranges, dryers
Elevator cable	E	18-14	2 or more	Rubber	Cotton	Three cotton, outer one flame- retardant and moisture- resistant	Elevator lighting and control	Non- hazardous locations
	EO	18-14	2 or more	Rubber	Cotton	One cotton and a neoprene jacket	Elevator lighting and control	Hazardous locations
	ET	18-14	2 or more	Thermoplastic	Rayon	Three cotton, outer one flame- retardant and moisture- resistant	Elevator lighting and control	Non- hazardous locations

Table B-9. Deep boxes

Box Dimensions, inches	Maximum Number of Conductors
	No 14	No 12	No 10	No 8
1 1/2 x 3 1/4 octagonal	5	5	4	0
1 1/2 x 4 octagonal	8	7	6	5
1 1/2 x 4 square	11	9	7	5
1 1/2 x 4 11/16 square	16	12	10	8
2 1/8 x 4 11/16 square	20	16	12	10
1 3/4 x 2 3/4 x 2	5	4	4	4
1 3/4 x 2 3/4 x 2 1/2	6	6	5	0
1 3/4 x 2 3/4 x 3	7	7	6	0

Table B-10. Shallow boxes (less than 1 1/2 inches deep)

Box Dimensions, inches	Maximum Number of Conductors
	No 14	No 12	No 10
3 1/4	4	4	3
4	6	6	4
1 1/4 4 square	9	7	6
4 11/16	8	6	6

Table B-11. Support for nonmetallic conduit runs

Size of Conduit, inches	Maximum Spacing Between Supports, feet
1/2	4
3/4	4
1	5
1 1/4	5
1 1/2	5
2	5
2 1/2	6
3	6
3 1/2	7
4	7
5	7
6	8

Table B-12. Full-load current, single-phase AC motors

HP	115 V	230 V	440 V
1/6	4.4	2.2	--
1/4	5.8	2.9	--
1/3	7.2	3.6	--
1/2	9.8	4.9	--
3/4	13.8	6.9	--
1	16	8	--
1 1/2	20	10	--
2	24	12	--
3	34	17	--
5	56	28	--
7 1/2	80	40	21
10	100	50	26

Table B-13. Full-load current, three-phase AC motors

HP	Induction-Type Squirrel-Cage and Wound Rotor Amperes					Synchronous-Type Unity Power Factor Amperes
	110 V	220 V	440 V	550 V	2,300 V	220 V	440 V	550 V	2,300 V
1/2	4	2	1	0.8	--	--	--	--	--
3/4	5.6	2.8	1.4	1.1	--	--	--	--	--
1	7	3.5	1.8	1.4	--	--	--	--	--
1 1/2	10	5	2.5	2.0	--	--	--	--	--
2	13	6.5	3.3	2.6	--	--	--	--	--
3	--	9	4.5	4	--	--	--	--	--
5	--	15	7.5	6	--	--	--	--	--
7 1/2	--	22	11	9	--	--	--	--	--
10	--	27	14	11	--	--	--	--	--
15	--	40	20	16	--	--	--	--	--
20	--	52	26	21	--	--	--	--	--
25	--	64	32	26	7	54	27	22	5.4
30	--	78	39	31	8.5	65	33	26	6.5
40	--	104	52	41	10.5	86	43	35	8
50	--	125	63	50	13	108	54	44	10
60	--	150	75	60	16	128	64	51	12
75	--	185	93	74	19	161	81	65	15
100	--	246	123	98	25	211	106	85	20
125	--	310	155	124	31	264	132	106	25
150	--	360	180	144	37	--	158	127	30
200	--	480	240	192	48	--	210	168	40

Table B-14. Standard loads for branch circuits and feeders and demand factors for feeders

Occupancy	Standard Loads, Watts per square foot	Feeder-Demand Factor
Armories and auditoriums	1	100%
Banks	2	100%
Barber shops	3	100%
Churches	1	100%
Clubs	2	100%
Dwellings	3	100% for first 3,000 watts, 35% for next 117,000, 25% for excess above 120,000
Garages	0.5	100%
Hospitals	2	40% for first 50,000 watts, 20% for excess over 50,000
Office buildings	5	100% for first 20,000 watts, 70% for excess over 20,000
Restaurants	2	100%
Schools	3	100% for first 15,000 watts, 50% for excess over 15,000
Stores	3	100%
Warehouses	0.25	100% for first 12,500 watts, 50% for excess over 12,500
Assembly halls	1	100%

Table B-15. Requirements for branch circuits

Type FEP, FEPB, R, RW, RU, RUW, RH-RW, SA, T, TW, RH, RUH, RHW, RHH, THHN, THW, and THWN Conductors in Raceway or Cable
Circuit Rating	15 amp	20 amp	30 amp	40 amp	50 amp
Conductors (min size): Circuit wires* Taps	14 14	12 14	10 14	8 12	6 12
Overcurrent protection	15 amp	20 amp	30 amp	40 amp	50 amp
Outlet devices: Lamp holders permitted Receptacle rating	Any type 15 max amp	Any type 15 or 20 amp	Heavy duty 30 amp	Heavy duty 40 and 50 amp	Heavy duty 50 amp
Maximum load	15 amp	20 amp	30 amp	40 amp	50 amp
*These current capacities are for copper conductors with no correction factor for temperature (see Tables B-3 through B-7).

Table B-16. Voltage drop table (based on 3% drop)

Verify Selected Conductor for Current-Carrying Capacity (Tables B-2 through B-7, pages B-2 through B-9)*
For 110 V Circuit Distance to Load, in feet											For 120 V Circuit Distance to Load, in feet
Load in Amps	50	75	100	125	150	200	250	300	400	500	Load in Amps	100	200	300	400	500	600	700	800	900	1,000
15	10 12	8 10	8 10	6 8	6 8	4 6	4 6	3 4	2 4	1 3	15	12 12	8 10	6 8	4 6	4 6	3 4	2 4	2 4	1 3	1 3
20	10 12	8 10	6 8	6 8	4 6	4 6	3 4	2 4	1 3	1/0 2	20	10 12	6 8	4 6	4 6	3 4	2 4	1 3	1 3	1/0 2	1/0 2
25	8 10	6 8	6 8	4 6	4 6	3 4	2 4	1 3	1/0 2	2/0 1	25	8 10	6 8	4 6	3 4	2 4	1 3	1/0 2	1/0 2	2/0 1	2/0 1
30	6 10	6 8	4 6	4 6	3 4	2 4	1 3	1/0 2	2/0 1	3/0 1/0	30	6 10	4 6	3 4	2 4	1 3	1/0 2	2/0 2	2/0 1	3/0 1/0	3/0 1/0
40	6 8	4 6	4 6	3 4	2 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	40	4 8	4 6	2 4	1 3	1/0 2	2/0 1	3/0 1/0	3/0 1/0	4/0 2/0	4/0 2/0
50	4 8	4 6	3 4	2 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	300 3/0	50	4 8	3 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	4/0 2/0	250 3/0	300 3/0
60	4 6	2 4	2 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	250 3/0	350 4/0	60	4 6	2 4	1/0 2	2/0 1	3/0 1/0	4/0 2/0	250 2/0	250 3/0	300 4/0	350 4/0
70	4 6	2 4	1 3	1/0 2	2/0 2	3/0 1/0	4/0 2/0	250 2/0	300 4/0	400 250	70	4 6	1 3	2/0 2	3/0 1/0	4/0 2/0	250 2/0	300 3/0	300 4/0	350 4/0	400 250
80	4 6	2 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	250 3/0	350 4/0	500 250	80	4 6	1 3	2/0 1	3/0 1/0	4/0 2/0	250 3/0	300 4/0	350 4/0	400 250	500 250
90	2 4	1 3	1/0 2	2/0 1	3/0 1	4/0 2/0	250 3/0	300 3/0	400 250	500 300	90	2 4	1/0 2	3/0 1/0	4/0 2/0	250 3/0	300 4/0	350 4/0	400 250	500 300	500 300
100	2 4	1 3	1/0 2	2/0 1	3/0 1/0	4/0 2/0	300 3/0	350 4/0	500 250	600 350	100	2 4	1/0 2	3/0 1/0	4/0 2/0	300 3/0	350 4/0	400 250	500 250	500 300	600 350
*Example: A building using open wiring required 20 amperes (at 110 V) to be supplied to a load located 150 feet from the circuit breaker. From Tables B-2 and B-7 (assuming R-type copper wire is used), the minimum size wire for this circuit is No 14. From the above table, a No 6 copper wire is required to limit the voltage drop to 3%. Therefore, a No 6 copper wire should be used. If the wire available were aluminum, then the minimum size is No 12, and for a maximum voltage drop of 3%, a No 4 must be used.

Table B-17. Support for rigid metal conduit runs

Size of Conduit, inches	Maximum Distance Between Rigid Metal Conduit Supports, feet
1/2	10
3/4	10
1	12
1 1/4	14
1 1/2	14
2	16
2 1/2	16
3	20

Table B-18. Radius of conduit bends

Size of Conduit, inches	Conductors Without Load Sheath, inches	Conductors With Load Sheath, inches
1/2	4	6
3/4	5	8
1	6	11
1 1/4	8	14
1 1/2	10	16
2	12	21
2 1/2	15	25
3	18	31
3 1/2	21	36
4	24	40
5	30	50
6	36	61

Table B-19. Minimum size (inches) of conduit of electrical metallic tubing to contain a given number of 800-volt conductors

AWG	Number of Conductors (Types R, RW, RH, RU, RUW, TF, T, and TW)
	1	2	3	4	5	6	7	8	9
18	1/2	1/2	1/2	1/2	1/2	1/2	1/2	3/4	3/4
16	1/2	1/2	1/2	1/2	1/2	1/2	3/4	3/4	3/4
14	1/2	1/2	1/2	1/2	3/4	3/4	1	1	1
12	1/2	1/2	1/2	3/4	3/4	1	1	1	1 1/4
10	1/2	3/4	3/4	3/4	1	1	1	1 1/4	1 1/4
8	1/2	3/4	3/4	1	1 1/4	1 1/4	1 1/4	1 1/2	1 1/2
6	1/2	1	1	1 1/4	1 1/2	1 1/2	2	2	2
4	1/2	1 1/4	1 1/4	1 1/2	1 1/2	2	2	2	2 1/2
3	3/4	1 1/4	1 1/4	1 1/2	2	2	2	2 1/2	2 1/2
2	3/4	1 1/4	1 1/4	2	2	2	2 1/2	2 1/2	2 1/2
1	3/4	1 1/2	1 1/2	2	2 1/2	2 1/2	2 1/2	3	3
1/0	1	1 1/2	2	2	2 1/2	2 1/2	3	3	3
2/0	1	2	2	2 1/2	2 1/2	3	3	3	3 1/2
3/0	1	2	2	2 1/2	3	3	3	3 1/2	3 1/2
4/0	1 1/4	2	2 1/2	3	3	3	3 1/2	3 1/2	4

Table B-20. Size conduit of electrical metallic tubing for combinations of conductors (percentage of cross-sectional area of conduit or tubing)

Conductors	Number of Conductors
	1	2	3	4	4+
Not lead covered	53	31	40	40	40
Lead covered	55	30	40	38	35
For rewiring existing conduits	60	40	40	50	50

Table B-21. Dimensions and percent of area of conduit and tubing for combinations

Size of Conduit, inches	Internal Diameter, inches	Area, square inches
		Total 100%	Not Lead Covered				Lead Covered
			1 Cond 53%	2 Cond 51%	3 Cond 43%	4+ Cond 40%	1 Cond 55%	2 Cond 30%	3 Cond 40%	4 Cond 38%	4+ Cond 35%
1/2	0.622	0.30	0.16	0.09	0.13	0.12	0.17	0.09	0.12	0.11	0.11
3/4	0.824	0.53	0.28	0.16	0.23	0.21	0.29	0.16	0.21	0.20	0.19
1	1.049	0.86	0.46	0.27	0.37	0.34	0.47	0.26	0.34	0.33	0.30
1 1/4	1.380	1.50	0.80	0.47	0.65	0.60	0.83	0.65	0.60	0.57	0.53
1 1/2	1.610	2.04	1.08	0.63	0.88	0.82	1.11	0.61	0.82	0.78	0.71
2	2.067	3.36	1.78	1.04	1.44	1.34	1.85	1.01	1.34	1.28	1.18
2 1/2	2.469	4.79	2.54	1.48	2.06	1.92	2.63	1.44	1.92	1.82	1.68
3	3.068	7.38	3.91	2.29	3.17	2.95	4.06	2.21	2.95	2.80	2.58
3 1/2	3.548	9.90	5.25	3.07	4.26	3.96	5.44	2.97	3.96	3.76	3.47

Table B-22. Dimensions of rubber-covered and thermoplastic-covered conductors

AWG	Types R, RH, RW		Types T, TW, TF, RU
	Approximate Diameter, inches	Approximate Area, square inches	Approximate Diameter, inches	Approximate Area, square inches
18	0.146	0.0167	0.100	0.0088
16	0.158	0.0196	0.118	0.0109
14	0.171	0.0230	0.131	0.0135
12	0.188	0.0278	0.148	0.0172
10	0.242	0.0460	0.168	0.0224
8	0.311	0.0760	0.228	0.0471
6	0.397	0.1238	0.323	0.0819
4	0.452	0.1605	0.372	0.1087
3	0.481	0.1817	0.401	0.1263
2	0.513	0.2067	0.433	0.1473
1	0.508	0.2715	0.508	0.2027
1/0	0.629	0.3107	0.549	0.2367
2/0	0.675	0.3578	0.505	0.2781
3/0	0.727	0.4151	0.647	0.3288
4/0	0.785	0.4810	0.705	0.3904

Table B-23. Characteristics of wire

Size AWG or MCM	No Wires	Diameter		Resistance, ohms per 1,000 feet
		Inches	Millimeters	Copper	Aluminum
14	Solid	0.0641	1.63	2.57	4.22
12	Solid	0.0808	2.05	1.62	2.66
10	Solid	0.102	2.59	1.02	1.67
8	Solid	0.129	3.27	0.640	1.05
6	7	0.184	4.67	0.410	0.674
4	7	0.232	5.89	0.260	0.424
3	7	0.260	6.60	0.205	0.336
2	7	0.292	7.41	0.162	0.266
1	19	0.332	8.42	0.129	0.211
1/0	19	0.373	9.46	0.102	0.168
2/0	19	0.418	10.6	0.0811	0.133
3/0	19	0.470	11.9	0.0642	0.105
4/0	19	0.528	13.3	0.0509	0.0836
250	37	0.575	14.6	0.0431	0.0780
300	37	0.630	16.0	0.0360	0.0590
350	37	0.681	17.3	0.0308	0.0505
400	37	0.728	18.5	0.0270	0.0442
500	37	0.814	20.6	0.0216	0.0354
600	61	0.893	22.7	0.0180	0.0295
700	61	0.964	24.5	0.0154	0.0253
150	61	0.998	25.4	0.0144	0.0236