Air Handlers are manufacturers of Heating, Ventilating and Air Conditioning Equipment for the building services industry

Air Handlers Celebrating 25+ Years of Success 1989 - 2015

Operating and Maintenance Manual

Belt Tensioning Instructions


Tensioning Forces

Belt Section
Force required to deflect belt 16mm per metre of span
Small Pulley Diameter
Kilogram Force
SPZ 56-95 mm 1.3-2.0 kg
100-140 mm 2.0-2.5 kg
SPA 80-132 mm 2.5-3.6 kg
140-200 mm 3.6-4.6 kg
SPB 112-224 mm 4.6-6.6 kg
236-315 mm 6.6-8.7 kg
SPC 224-355 mm 8.7-11.7 kg
375-560 mm 11.7-15.3 kg

Belt Tensioning Procedure Using A Belt Tension Indicator

  • Calculate the deflection distance in mm on a basis of 16mm per metre of centre distance.
  • Set the lower marker ring at the deflection distance required in mm on the lower scale.
  • Set the upper marker ring against the bottom edge of the tube.
  • Place the belt tension indicator on top of the belt at the centre of the span, and apply a force at the right angles to the belt deflecting it to the point where the lower marker ring is level with the top of the adjacent belt.
  • Read off the force value indicated by the top edge of the marker ring.
  • Compare this force to the kgf value in the table above.
  • If a Belt Tension Indicator is not available, a spring balance and rule will suffice.

After the drive has been running for approximately 30 minutes, the tension should be checked and readjusted to the higher value, if necessary.