The Use Case

A woodworking shop wants to run a large stationary table saw (≈4 HP) together with a high‑capacity dust collector (≈3.5 HP). Both are three‑phase motors that together total about 7.5 HP. The workshop only has standard 230/240 V single‑phase service.

What Usually Matters for Sizing

  1. Motor nameplates – HP, voltage, LRA/FLA for each motor; the dust collector often has a high start surge.
  2. Combined load – Add the two motors’ starting currents to determine the peak demand on the converter.
  3. Voltage – Most woodworking equipment runs at 230‑240 V three‑phase, so no transformer is needed if the single‑phase supply matches that voltage.
  4. Duty cycle – Intermittent use (e.g., saw on for short cuts) versus continuous dust collection influences required thermal capacity.
  5. Space & ventilation – Both the converter and motors generate heat; adequate clearance is essential.

Common Mistakes to Avoid

  • Using a static phase converter – Static units can cause voltage drop during simultaneous starts, leading to reduced cutting performance or dust collector stall.
  • Undersizing for start‑up – The combined LRA of the saw and collector can be 3–4 × the rated current; sizing only by total HP will under‑estimate required capacity.
  • Assuming any “7‑HP” converter works – Phoenix’s GP15NL is a proven match for ~7‑8 HP combined loads; other models may lack sufficient start‑up power.
  • Neglecting breaker rating – The single‑phase panel must be able to supply the converter’s input current, typically 1.5–2 × the total motor FLA.

Practical Phoenix Recommendation

Evidence from similar woodworking setups points to the GP15NL rotary phase converter as an optimal solution for a 7.5 HP combined load. The GP15NL provides strong start‑up torque and stable voltage, which is crucial when both the saw and dust collector start together.

Because the equipment operates at standard 230/240 V three‑phase, no additional transformer is required; the GP15NL can be fed directly from the existing single‑phase service. Ensure the building’s main breaker can handle the converter’s input amperage (often a 60–80 A breaker for this size).

Final sizing must be confirmed against each motor’s nameplate, especially LRA values, and cross‑checked with the site’s single‑phase capacity.

What to Have Ready Before Calling

  1. Nameplates of both the table saw motor and dust collector motor (HP, voltage, LRA/FLA).
  2. Single‑phase service information – voltage, breaker size, distance to equipment.
  3. Expected usage pattern – continuous dust collection vs. intermittent cuts.
  4. Physical layout – space for the converter, clearance for ventilation, and grounding details.
  5. Any existing harmonic filters or power conditioning devices.

With these details in hand, Phoenix can verify that a GP15NL will reliably power your woodworking line without unnecessary upgrades.