Typical Specs – 480 VAC 3PH 3W Ventilation MCC

Electrical Ratings

• Voltage: 480 VAC

• Frequency: 60 Hz

• Phase: 3-Phase

• Wire configuration: 3-Wire (L1-L2-L3, no neutral)

• Voltage class: up to 600 V low-voltage MCC systems

Bus Ratings

• Main horizontal bus: typically 600–3200 A capacity

• Copper bus bars (tin-plated)

• Short-circuit rating: commonly 33 kA – 65 kA fault current withstand

Main Protection

• Main circuit breaker or fusible disconnect

• Example typical rating:

  • 400 A main breaker

  • bottom or top feed

Motor Control Equipment

Ventilation MCCs usually control fans and blowers, so they include:

• Motor starters (FVNR – full voltage non-reversing)

• Soft starters for larger motors

• Variable Frequency Drives (VFDs)

• Overload relays

• Control transformers

• Feeder breakers or disconnect switches

Typical motor sizes in ventilation systems:

• 5–20 HP exhaust fans

• 20–100 HP supply fans

Mechanical / Cabinet Specs

Structure

• Modular vertical sections

• Typical height: ~90 in (2286 mm)

• Section width: ~20 in

• Depth: 16–21 in

Enclosure

• NEMA Type 1 (indoor) or Type 12 / 3R optional

• Ventilated cabinet design for heat dissipation

Construction

• Steel enclosure (12–14 gauge)

• Copper vertical and horizontal bus

• Plug-in or withdrawable buckets