Servicing the APU Generator Belt. Determining if a belt adjustment or replacement is required

Transcription

1 Affected Parts: 40-S31-31K Generator Belt Kit, PG1040 Tool, 30-S70-82K Servicing the APU Generator Belt UNIT ONLY TO BE SERVICED BY QUALIFIED PERSONNEL Determining if a belt adjustment or replacement is required With the APU running and all electrical loads off, turn on the fan only to low. Measure the voltage at the hotel power outlet using a suitable meter. If the voltage is above 105 VAC, no adjustment is required. If the voltage is below 105 VAC, check the belt tension as follows: Disconnect 12 pin connector Remove the upper access panel Disconnect the 12 pin connector from the APU Controller (Figure 1) Remove the upper and lower APU enclosures Using a straightedge along the lower edge of the engine and generator pulleys, measure the deflection of the belt when a force of 25 lbs is applied pulling the belt. If belt deflection is in excess of 1 (2.5 cm), the belt needs to be adjusted by removing a link See last page of this document for link removal instructions Figure 1 APU Control Module Technical Support Available apuservice@gficontrolsystems.com or Page 1 of 5

2 If the belt is being replaced, cut the old belt for removal. If the belt is being removed for service, mark the belt direction and remove by reversing the installation instructions. Replacing the belt The belt installation tool PG1040 will be required for removal and installation of the generator belt. Figure 2 Belt Installation Tool PG1040 Turn the engine until a pulley bolt is at the top and remove the bolt Remove Tensioner Figure 3 Figure 4 If the APU is equipped with a tensioner, remove the 3 bolts retaining the tensioner, remove and discard the tensioner assembly Page 2 of 5

3 Install the belt installation tool using the provided bolt Place the belt over the generator pulley and the installation tool (new belt = 46 links) Ensure that the belt is installed in the proper direction. The belt is marked with arrows indicating the proper direction of rotation (Figure 5 and Figure 10) Ensure the belt is not cut or damaged by any sharp edges during installation Hold the belt firmly in the pulley grove with one hand Figure 5 Figure 6 Rotate the crankshaft by using a wrench on the engine crankshaft pulley (Figure 7) Use a wrench on the generator center bolt to prevent the engine from springing backwards when repositioning the wrench on the crankshaft pulley (Figure 8) CAUTION: Do not allow the engine to turn backwards during the belt installation. Reversing direction during the belt installation can result in damage to the belt. Figure 8 Figure 7 Page 3 of 5

4 With the belt securely in the pulley grove, turn the crankshaft until the tool rotates to the bottom lifting the belt onto the pulley (Figure 9) Inspect the belt for any damage caused by the installation If any links are damaged during installation the belt must be removed and the damaged links replaced Figure 10 Belt Direction of Travel Figure 9 Remove the belt installation tool and replace the pulley bolt Apply Red Loctite 262 to the bolt and torque to 18 Ft./ Lbs Install the upper and lower enclosures and reconnect the 12 pin connector at the APU Controller. Page 4 of 5

5 Removing a Link Turn the belt inside out so the tabs are to the outside. Bend the belt back as far as possible (Figure 11) Twist one tab 90 degrees (Figure 12) Figure 11 Figure 12 Turn the belt and separate (Figure 13) Figure 13 Figure 14 Turn the last link to separate and remove (Figure 14) Reassemble by inserting the tab on the free end through the 2 tabs on the opposite end and turn to lock. Turn the tab and insert back through the belt as in figure 12. Turn the tab back to its normal position Turn the belt back to the normal position. For additional information see Page 5 of 5