TC2

pjvr99, we did the swapping of the Indicator and amplifier leads before as what you suggested with no effect to the control problem. In fact, we have 2 indicators on our test console, one reading the TIT and the other reading the temperature to the TD Amp. Both reading the same with difference less than 3°C. Only thing that I am concerned is when we did the TD Cal. we observed that the Fixed Phase voltage of 90 V for the Bendix Amp but only 80 V for the Reven. I am not too sure this will affect the motor function on the TD Valve but again the limits under the test procedures is acceptable as long as it is over 75 V. What we intend to do during the next engine test is to measure the output voltage to all the coils (Motor and Generator) of the TD Valve via the jumper connection for the J3 lead that we fabricated and compare the difference between the Bendix and Reven Amp as I am also thinking that if the voltage is too low, movement of the plunger inside the TD Valve may be affected due to sticky gears and bushings.

Hi, Just to give an update, we are far from solving the problem and continued to fail QEC engines testing from the Test Cell only with the Raven TD Amplifier. Further action and troubleshooting on the past weeks on the following yielded not better result: -Run engine with Ground Power Unit (GPU) from Flight Line for the AC supply. Problem persisted -Verify TD Control System using another TD Cal Set. No fault found -Sent both Bendix and Reven TD Amplifiers to the Components shop to verify the operation using a master test set. Both passed test. In the interim, we released engine tested with Bendix Amplifier and pending operator to feedback on ground run result after the QEC engine is fitted to the aircraft with the Raven Amplifier. In my opinion, it must be a test cell related Power supply problem. We have so far focus very much on the AC Power supply. Can anyone share will the DC supply could contribute to this problem? If pjrv99 has any recommendation. Please feel free to enlighten me as the pressure is building up badly on my end.