Power Distribution for Manufacturing
Discrete manufacturing plants — automotive, food & beverage, packaging, plastics, metals — depend on reliable transformers and switchgear feeding 480 V plant equipment. Our equipment is built for plant duty: rugged, properly sized for VFD-heavy load, and easy to maintain.
What Makes Manufacturing Different
- Mixed loads: motor-heavy (drives, conveyors, compressors), with welding, induction heating, and process automation in many plants.
- Process criticality: some lines (glass float lines, paper machines, semiconductor fabs) cannot tolerate any unplanned outage.
- Indoor placement: most plants house transformers inside the production envelope — fire safety drives dry-type selection.
- Harmonic content: VFDs are universal in modern manufacturing. K-13 minimum on most feeders.
What We Build for Manufacturing
- Cast resin and VPI dry-type transformers — the workhorse for indoor distribution. 500 kVA to 5 MVA, K-13 standard for VFD-heavy applications.
- MV unit substations — combined MV switchgear + step-down transformer + LV switchgear in a single skid. Reduces site work and accelerates commissioning.
- LV motor control centers (MCCs) per UL 845 — bucket-style construction, drawout starters, integrated VFDs available.
- Process-critical redundant feeders — dual transformers with secondary tie, so a single transformer fault doesn't shut the line down.
- Specialty units — induction heating transformers, welding transformers, isolation transformers for sensitive process control loads.
Specification Considerations
Diversity Factor
Plant connected load rarely matches actual demand. Typical diversity is 60–70% — meaning a 2000 kVA connected load is usually fine on a 1500 kVA transformer. Don't oversize; oversized transformers run inefficient at light load.
K-Factor for VFDs
Modern manufacturing plants are full of VFDs. Spec K-13 minimum on every feeder serving multiple drives. K-20 if VFD load > 75%. See harmonics article.
Process-Critical Lines
For lines where downtime cost is > $10K/hour (typical for paper, glass, automotive paint), invest in redundant feeders. Two transformers + secondary tie + automatic transfer scheme. Adds maybe 30% to the equipment cost; pays back in a single avoided outage.
Future Expansion
Plants grow. Spec the transformer 25–40% above current demand to leave headroom. Spec the switchgear with at least 2 spare feeder breakers and a future bay tie.
A 13.8 kV / 480 V transformer with 5.75% impedance puts ~25 kA of fault current at the secondary. Spec 65 kAIC SCCR minimum on the LV switchboard, 100 kAIC for larger plants. Under-specifying SCCR is the most common code violation we find on existing manufacturing installations.
Typical Project Profile
Mid-Size Plant Expansion (Auto Tier-2 supplier)
- 13.8 kV utility service, single feed
- 2× 1500 kVA cast resin step-down (480 V), K-13, 80°C rise
- LV switchboards (3000 A, 65 kAIC) with manual transfer between transformers
- MCCs for production line motors
- Lead time: 14 weeks
- Includes NETA acceptance testing
Plant Expansion or New Line?
From a single replacement transformer to a complete unit substation — we can spec and build it.