Title: Instructions manual - THGT fan.pdf
8.3.8. Rotate impeller and check tip gap in minimum 4 equi-spaced locations and adjust if necessary. Tip gap “S” to duct or impeller gap / inlet meets data obtained in Pre-start checklist. In absence of any specific data this should be a minimum of 1% of the impeller diameter “D” and never less than 2mm, or more than 20mm, in radial direction. Fig 18. Adjustment can be made by adjusting motor center-line for axial fans. Tighten motor fixings to correct torque Fig 19. Recheck gap between impeller and duct is correct in minimum 4 equi-spaced locations. Fig 18. If not, repeat assembly until gap between rotating and fixed materials is correct. Record these gap dimensions on inspection document. Affix Repair label to fan with relevant details. Fig 20.Warning for ATEX: This running clearance “S” between impeller “D” and duct / case or inlet cone is critical for safe fan operation. See Annex 5: Typical running clearance for axial fans:-