What Is MV-105 Cable?
If you're specifying medium-voltage feeder or distribution cable, you've probably seen "MV-105" on a spec sheet and wondered what the number actually refers to. It's simpler than it looks — and knowing what it means can help you avoid over-buying or under-specifying on your next job.
Breaking Down the Name
- MV — Medium Voltage, generally cable rated above 2,000 volts (common classes: 5kV, 15kV, 25kV, 35kV)
- 105 — the maximum continuous conductor operating temperature, in Celsius
MV-105 cable is rated to run continuously at 105°C, compared to older MV-90 cable, which is limited to 90°C continuous. That 15-degree difference translates directly into higher ampacity — MV-105 can carry more current through the same conductor size before hitting its thermal limit.
MV-105 cable is built to handle three temperature thresholds:
ConditionMax Conductor TempContinuous operation105°CEmergency overload140°CShort circuit250°C
Construction
MV-105 cable is a layered system, typically:
- Conductor — annealed stranded copper or aluminum
- Conductor shield — semi-conducting layer that manages electrical stress
- Insulation — EPR or TR-XLPE, chosen for dielectric strength and moisture resistance
- Insulation shield — strippable semi-conducting layer for clean terminations
- Metallic shield — copper tape, providing a fault-current and grounding path
- Jacket — sunlight-resistant, flame-retardant PVC (CPE and LLDPE jackets are also available for tougher chemical or moisture exposure)
Where It's Used
MV-105 is common in:
- Utility primary distribution (12.47kV / 13.8kV feeders)
- Industrial plants — refineries, chemical plants, steel mills feeding large motors and switchgear
- Direct burial, duct, tray, and aerial installations
- Commercial/industrial service entrances
Standards to Look For
Legitimate MV-105 cable should carry:
- UL 1072
- ICEA S-93-639 / NEMA WC74
- AEIC CS8 (EPR) or CS9 (XLPE/TR-XLPE) on utility-grade jobs
- IEEE 383 / 1202 flame testing on larger conductor sizes
MV-105 vs. MV-90: Which Do You Need?
If you're fighting ampacity limits on an existing conductor size, running feeders in a hot environment, or specifying new utility or industrial work, MV-105 has largely become the default rather than the upgrade. MV-90 still shows up in older installations and replacement-in-kind jobs, but most new specs call for 105°C-rated cable.
Get the Right MV-105 Cable for Your Job
Mid America Wire & Cable stocks power cable across major manufacturers and standards, with same-day dispatch to all 50 states. If you're specifying MV-105 for an upcoming project, browse our catalog or request a quote — our technical sales team can help confirm voltage class, conductor size, and insulation type before you order. Or call us directly at (918) 622-1489.
