2.5 Utility Capacity Planning & New Equipment Hookup Checklist

A facility is a finite resource. Every new Reflow Oven or Wave Solder machine consumes a slice of the building's total capacity (Amps, CFM, Cooling Tons). If you treat the facility as an infinite socket, you will eventually trip the main breaker or collapse the compressed air pressure, causing a factory-wide blackout.

This chapter defines the engineering protocol for Capacity Management and the Safe Hookup of new assets.

Capacity Planning Logic (The 80% Rule)

Do not design to the limit. Facilities infrastructure must maintain a 20% Safety Margin (Headroom) to absorb startup currents and demand spikes.

The Decision Matrix:

Before purchasing any equipment, compare its nameplate rating against the facility's available headroom.

• Electrical Load:
  • If Panel Load > 80% -> Then STOP. Install a new sub-panel or upgrade the transformer. Do not double-tap breakers.
• Exhaust (VOC/Heat):
  • If Duct Velocity < 10 m/s (after hookup) -> Then Solder fumes will settle in the duct, creating a fire hazard. Re-balance the system.
• Cooling (HVAC):
  • If Heat Load (BTU) > Zone Capacity -> Then The SMT line will overheat (>26°C), causing solder paste viscosity failures.

Pro-Tip: Use "Diversity Factors" when calculating load. A Reflow Oven draws 100% current only during the 30-minute warm-up. Its running load is typically 40-50%. Schedule line startups sequentially (staggered by 15 mins) to reduce peak demand.

The Hookup Protocol (The Handshake)

Production owns the machine; Facilities owns the wall. The "Hookup" is the formal handshake between these two domains. No machine is energized without a signed Hookup Permit.

1. Electrical Connection

• Cabling: Cable size must be calculated based on the 75°C column of NEC/IEC tables, derated for tray packing.
• Isolation: Every machine must have a local disconnect (Rotary Switch) within 2 meters of the operator, lockable in the OFF position (LOTO compliant).
• Phase Rotation: Verify Clockwise (L1-L2-L3) rotation before connecting motors. A reverse-running pump can destroy itself in seconds.

2. Pneumatics (Air & Nitrogen)

• Diameter: Do not starve the machine. If the inlet is 12mm, the supply hose must be ≥ 12mm.
• Filtration: Verify the "Point-of-Use" filter (ISO Class 1.2.1) is installed between the facility drop and the machine inlet.
• Isolation: Install a manual ball valve to bleed pressure for maintenance.

3. Extraction (Exhaust)

• Static Pressure: Measure the suction at the machine collar.
  • Reflow Target: -200 to -500 Pa (or per OEM spec).
  • Risk: Too high = flux is sucked off the board. Too low = fumes escape into the room.
• Ducting: Use rigid metal spiral ducting. Flexible hose (flex-duct) causes high turbulence and is limited to < 1 meter lengths.

Labeling Standard

An unlabeled breaker is a latent risk. If a smoke event occurs, the responder must know exactly which switch kills the power.

• Machine End: Label the drop: "Fed from Panel P-2, Breaker 14".
• Panel End: Label the breaker: "Supply to SMT Line 3 Reflow".
• Color Code:
  • Red: 400V/230V Power.
  • Blue: Compressed Air.
  • Green: Nitrogen.
  • Yellow: Vacuum.

Final Checklist