CHANGING IMPACT IMPELLERS

1st October 2005

Important:- This kit includes a complete impeller assembly. If the unit is currently fitted with impellers of a different design to those included in this kit, it is essential that all the impellers in the unit are replaced.

This kit contains:-

Removing the existing impellers:-

1) Remove the plastic casing from the unit.

2) Remove the retaining screws from the electrics panel and hinge to one side. Remove the retaining screws and ease the top of the coil away from the chassis to reveal the impellers.

3) Remove the motor from the chassis end plate and discard the coil spring and any washers fitted to the shaft.

4) Removing impeller 1 by pulling the free, motor end of the impeller forwards until clear of the chassis end plate then withdrawing th efan and bearing from the rubber bearing mount. Discard the fan and bearing assembly.

5) For units with more than 1 impeller fitted, remove each fan in sequence as described above, discarding the fans and the intermediate coil springs.

Fitting the replacement impellers:-

6) Impact 20/40 and CWW15/35

a) Taking the new impeller align the bearing with the rubber housing and push firmly until the bearing is fully engaged in the bearing housing.

b) Turn the impeller until the grub screw in the motor end faces forwards.

c) Taking the motor, align the flat of the 'D' shaft with the grub screw (i.e. also facing towards) and insert the motor shaft through the chassis end plate into the boss on the impeller. Re-mount the motor to the chassis end plate.

d) Using a 2.5mm A/F Allen key, tighten the grub in the end boss of the impeller down on to the flat of the motor shaft with a maximum torque of 850N/cm.

7) Impact 60/80 and CWW 55/75

a) Taking the new impeller, without the 'D' shaped shaft extension (Impeller 2) align the bearing with the rubber bearing housing furthest away from the motor position and push firmly until the bearing is fully engaged in the bearing housing.

b) Taking the remaining impeller, align the 'D' shaft and insert through the central divider plate into the boss of Impeller 2. Push firmly until the bearing is fully engaged in the bearing housing.

c) Turn impeller 1 until the grub screw in the motor end faces forwards.

d) Taking the motor, align the flat of the 'D' shaft with the grub screw (i.e. also facing forwards) and insert the motor shaft through the chassis end plate into the boss on the impeller. Re-mount the motor to the chassis end plate.

e) Using a 2.5mm A/F Allen key, tighten the grub screw in the end boss of the impeller down on to the flat of the motor shaft with a maximum torque of 850N/cm.

f) Turn the impellers until the grub screw in the end boss of impeller 2 aligns with the flat on the 'D' shaft of impeller 1.

g) Using a 2.5mm A/F Allen key, tighten the grub screw in the end boss of the impeller down on to the flat of the 'D' shaft with a maximum torque of 850N/cm.

8) Impact 100 and CWW 85

a) Taking the new 300mm impeller (impeller 3) align the bearing with the rubber bearing housing furthest away from the motor position and push firmly until the bearing is fully engaged in the bearing housing.

b) Taking one of the remaining impellers, align the 'D' shaft and insert through the central divider plate into the boss of impeller 3. Push firmly until the bearing is fully engaged in the bearing housing.

c) Repeat item 'b' for fitting the remaining impeller.

d) Turn impeller 1 until the grub screw in the motor end faces forwards.

e) Taking the motor, align the flat of the 'D' shaft through the chassis end plate into the boss on the impeller.

f) Using a 2.5mm A/F Allen key, tighten the grub screw in the end boss of the impeller down on to the flat motor shaft with a maximum torque of 850N/cm.

g) Turn the impellers until the grub screw in the end boss of impeller 2 aligns with the flat on the 'D' shaft of impeller 1. Using a 2.5mm A/F Allen key, tighten the grub screw in the end boss down on to the flat of the 'D' shaft with a maximum torque of 850N/cm.

h) Turn the impellers until the grub screw in the end boss of impeller 3 aligns with the flat on the 'D' shaft of impeller 2. Using a 2.5mm A/F Allen key, tighten the grub screw in the end boss down to the flat of the 'D' shaft with a maximum torque of 850N/cm.

9) Check that the impellers fit centrally in the unit and do not rub or catch on the mounting plates of the unit.

10) Reassemble the unit.