Service Bulletin TTC-SB-DHC3-03-REV-A

or 88) terminal of the new top start relay. Crimp a 3/8”70-10 ring terminal on the cable and install it on the relay. (see figure 2 for ring terminal clocking) 18. Fabricate jumper wire from hot side of battery master relay to the terminal (2 or 88a) of the normally closed relay using the MS22759/2-02-9 wire and one ½” 70-12 ring terminal (master relay) and one 3/8” 70-10 ring terminal (normally closed relay). Note that the ring terminal on the battery master must be installed upside down to allow installation of two ring terminals on one stud. Also, due to the short length of wire, ring terminal clocking and wire length are very critical. NOTE For all heavy gauge cables, be sure to use heat shrink on each end of the wire to prevent fraying of the braided shielding. 19. Cut the end of the heavy cable that runs from the top strain relief of the battery box to the j- box at the j-box end and remove the cable from both the j-box and battery box. 20. Install a new MS22759/2-02-9 cable from terminal (2 or 88a) on the start relay to the positive terminal on the Elcon connector for battery number 2 (the one further from the j- box) parallel/series transfer relay in the battery box as depicted in figures 2 & 3 using the same holes where the previous cable was removed. Use the 3/8” 70-10 ring terminals on both ends. Note ring terminal clocking prior to crimping terminals and verify that there is adequate length to connect to battery when installed. 21. Cut the heavy gauge wire coming thru the middle strain relief (from the battery master relay) of the battery box to the proper length to allow installation of the wire on the top (1 or 88) terminal of the parallel/series transfer relay (see figure 3). Crimp a 3/8” 70-10 ring terminal at the new cut length. TTC-SB-DHC3-03-REV-A 5 0ctober 01, 2006 22. Loosen the bottom heavy gauge strain relief on the battery box for the negative cable and push the cable further into the box to attach to the bottom post (4 or 87a) of the parallel/series transfer relay as depicted in figure 3. The existing 3/8” 70-10 ring terminal might have to be cut off and a new one installed to allow for proper clocking of the ring terminal. If the cable is not long enough, a new cable must be fabricated from the external power plug to the parallel/series transfer relay using the cable and 3/8” 70-10 ring terminals supplied in the kit. 23. Fabricate the heavy gauge wire from the negative terminal on the Elcon connector for battery number 2 (the one further from the j-box) to the top terminal (2 or 88a) of the parallel series transfer relay using the MS22759/2-02-9 wire and 3/8” 70-10 ring terminals that were supplied with the kit. 24. Fabricate the heavy gauge jumper wire from the top terminal (2 or 88a) of the parallel- series transfer relay to the bottom terminal (3 or 87) using the MS22759/2-02-9 wire and the 3/8” 70-10 ring terminals that were supplied with the kit. Again, pay careful attention to ring terminal clocking. (see figure 3) 25. Fabricate the heavy gauge wire from the positive terminal on the Elcon connector for battery number 1 to the top terminal (1 or 88) of the parallel/series transfer relay using the MS22759/2-02-9 wire and 3/8” 70-10 ring terminals. 26. Fabricate the heavy gauge wire from the negative terminal on the Elcon connector for battery number 1 to the bottom terminal (4 or 87a) of the parallel/series transfer relay using the MS22759/2-02-9 wire and 3/8” 70-10 ring terminals. 27. Permanently tighten the nuts and screws on all the relays. Tighten all strain relief clamps that were loosened during installation. Be careful not to over-tighten the strain relief clamps or pinch the two 18 gauge wires that run from the battery box to the j-box. THE FIREWALL FORWARD MODIFICATION IS COMPLETE 28. In the cockpit, remove the engine instrument panel to allow installation of the series start relay. 29. Install the series start relay (PN. KUP-5D55-24) on the left bulkhead as depicted in figure 4 using two MS27039-0808 screws, two AN960-08 washers, and two MS21083N08 nylon nuts. TTC-SB-DHC3-03-REV-A 6 0ctober 01, 2006 Remove the right battery master switch and install Parallel- Parallel/Series Toggle Switch and engraving Install the Series Start Relay to the backside of this bulkhead Figure 4 TTC-SB-DHC3-03-REV-A 7 0ctober 01, 2006 Figure 5 TTC-SB-DHC3-03-REV-A 8 0ctober 01, 2006 29. Remove the right battery master switch from the engine instrument panel and install the parallel/series switch 8501-K9 (provided with kit) NOTE If wire 325 and wire 1105 are on the left battery master switch, the left battery master must be removed and the right battery master should be moved to the left hole. 30. Remove wires 325 and 1105 from the battery master switch and cut the ring terminals off to facilitate removal from the engine instrument panel harness. Route the wires over to the Series Start Relay that was just installed. Connect wires 325 and 1105 to the appropriate marked wires of the series relay using the spade terminals provided in the kit (see figure 5). 31. Fabricate and install wire 600-A (MS22759/16-18-9) on the START/GEN switch on the same post as wire 407 using a #8 ring terminal. Route the wire along the existing harness to the Para/Series Toggle Switch and attach it to the appropriately marked terminal of the switch. (see fig. 5) 32. Fabricate and install wire 601-A (MS22759/16-18-9) on the FUEL ON/SPR switch on the same post as wire 404 using a #8 ring terminal. Route the wire along the existing harness to the Para/Series Toggle Switch and attach it to the appropriately marked terminal of the switch. (see fig. 5) 33. Fabricate wires 600 and 601 using wire(MS22759/16-18-9) and using #8 ring terminals, run them between the Para/Series Switch and the Series Start Relay and attach to appropriately marked leads or terminals.(see figure 5) 34. Permanently tighten all screws on the START/GEN switch and FUEL ON/SPR switch. If the battery master switches were flipped, check that the screws on the remaining battery master switch are not loose. 35. Open circuit breaker panel and remove the 10 amp Engine Controls circuit breaker and install the 15 amp circuit breaker (4200-001-15) supplied in its place. Close circuit breaker panel. 36. Secure all wires to the existing harnesses and re-install the engine instrument panel. THE COCKPIT MODIFICATION IS COMPLETE 37. Re-install the two aircraft batteries in the battery box and secure. Connect the two Elcon connectors to the batteries and safety wire. 38. Pull the ignition circuit breaker and verify that the engine cranks using the normal motoring procedure. NOTE The start system should crank normally, because the system does not switch to series until the fuel is turned on. 39. If system cranks normally, install battery box and j-box covers and test run engine. If engine does not crank normally, verify that wiring is correct and repeat step 36. TTC-SB-DHC3-03-REV-A 9 0ctober 01, 2006 40. Start engine using normal start procedures, at 12-15% (when the fuel is turned ON) the system will automatically switch to a series start (48 volt start as indicated by a more rapid acceleration) and will stay series until starter cutout at 55-60%. Verify that generator functions normally and that bus voltage is approx. 27 volts. Shut down engine. NOTE During the series phase of the start it may take substantially more fuel enrichment to keep the start temperature up at 675C, or you may not be able to reach 675C. This is normal. THE PARALLEL/SERIES START SYSTEM MODIFICATION IS COMPLETE Approval: This service bulletin is FAA approved. Man-hours: The modification should take no more than 16 man-hours. Material: The appropriate materials will be supplied in the service kit TTC-SK-DHC3-01. Tooling: 00 wire crimpers will be necessary to fabricate the heavy gauge cables. Weight and Balance: Add 5.3 pounds at station 42.0 TTC-SB-DHC3-03-REV-A 10 0ctober 01, 2006