12 awg is an option. But for a 50' cord - what we have specced handles the load very well. It's a seriously nice cord!
Here's the description for the cable we are sourcing...'
Applications:
SEOOW Flexible Portable Cord applications include include wiring for industrial machinery, washing machines and various other large appliances, heavy-duty tools, motors, and temporary electrical power and lighting installations for construction sites.
Features:
Excellent resistance to oil and moisture. High flexibility. Excellent abrasion resistance. Water-resistant. Sunlight-resistant. Temperature range: -50ºC to +105ºC
Standards:
UL Flexible Cord - UL Standard 62
CSA Flexible Cord - C22.2-49
NEC Article 501.140 Class I Div. 2
NEC Article 400
Federal Spec JC580
Passes CSA FT2 Flame Test
MSHA Approved
EPA 40 CFR, Part 26, Subject C, heavy metals per Table 1, TCLP method
Construction:
Conductors:
Fully annealed stranded bare copper per ASTM B-174
Insulation:
TPE
Specifications*:
Size: 14 AWG
Number of Conductors: 3
Conductor Strand: 41/30
Insulation Thickness: 1.14 mm / 0.045 inches
Jacket Thickness: 2.16 mm / 0.085 inches
Outside Diameter: 13.26 mm / 0.522 inches
Weight: 0.15 lbs per ft
Current Amps: 18