GENERATOR OUTPUT · FEEDERS · LEADS

Conductor Sizer

Select your generator load and installation details. Compare practical conductor sizes, flexible cable types, parallel runs, voltage drop, and estimated conduit fill.

Installation inputs

Generator load

System voltage System phase One-way length

Conductor material Terminal temperature

Use the lowest temperature rating: conductor insulation, breaker/panel lugs, switch, and generator terminals. A 90°C cable commonly still sizes from the 75°C column.

Conductor construction

Cable type Parallel sets per phase Target voltage drop

General generator feeder in conduitCanada & U.S. · Medium flexibility

Single insulated conductors. Use the wet-location marking where required.

CALCULATION RESULTS

Size comparison

Values are before conductor-count and ambient-temperature derating. Use the selected terminal-temperature column.

Size per conductor	One conductor	Parallel ampacity	Voltage drop	Status
14 AWG	20	20 A	19.2%	Undersized
12 AWG	25	25 A	12.1%	Undersized
10 AWG	35	35 A	7.6%	Undersized
8 AWG	50	50 A	4.8%	Undersized
6 AWG	65	65 A	3.1%	Undersized
4 AWG	85	85 A	1.9%	Undersized
3 AWGRecommended	100	100 A	1.5%	Meets target
2 AWG	115	115 A	1.2%	Meets target
1 AWG	130	130 A	1%	Meets target
1/0 AWG	150	150 A	0.8%	Meets target
2/0 AWG	175	175 A	0.6%	Meets target
3/0 AWG	200	200 A	0.5%	Meets target
4/0 AWG	230	230 A	0.4%	Meets target
250 kcmil	255	255 A	0.3%	Meets target
300 kcmil	285	285 A	0.3%	Meets target
350 kcmil	310	310 A	0.2%	Meets target
400 kcmil	335	335 A	0.2%	Meets target
500 kcmil	380	380 A	0.2%	Meets target
600 kcmil	420	420 A	0.1%	Meets target
700 kcmil	460	460 A	0.1%	Meets target
750 kcmil	475	475 A	0.1%	Meets target

CONDUIT CHECK

Estimated conduit fill

Enter every insulated conductor or cable that will occupy the raceway. For a multi-conductor cable, use the manufacturer’s overall cable diameter, not the individual conductor diameter.

This uses 53% fill for one conductor, 31% for two, and 40% for three or more. It is a planning aid. Confirm the actual cable O.D., raceway type, conductor adjustment, pulling tension, bend radius, and the applicable code table.

Insulated conductors/cables in raceway Actual outside diameter override

Calculated occupied area0.566 in²Suggested minimum nominal conduit1-1/4 inBased on approximately 0.49 in outside diameter each and a 40% fill limit.

Common generator choices

RW90 / THHN / XHHW-2: standard conductors pulled in conduit.
DLO: excellent flexibility for generator output leads and vibration-prone routing.
TECK90 / MC: robust mechanical protection where conduit is undesirable.
SOOW: portable, flexible connections, not a default permanent feeder.

Before you release a drawing

Confirm the generator breaker and terminal temperature rating.
Apply ambient and conductor-count derating.
Size neutral and equipment bonding conductors separately.
Check voltage drop at starting and non-linear loads, not only full-load amps.

Code reference boundary

This tool is an engineering starting point for 60 Hz AC systems, not a stamped design or a substitute for the current Canadian Electrical Code, NEC, equipment instructions, or your authority having jurisdiction.

Reference basis: CEC Table 2 and NEC Table 310.16-style ampacity principles for insulated conductors in raceway or cable, subject to their conditions of use.