We have 2 GE frame#9E 115 MW base load capacity gas turbines at our site. Both have been commissioned around 1999. HMI of Mark 5 had undergone up gradation from DOS based to Windows based, without any change whatsoever in control loops & systems. Recently, during a FSNL operation [initially the unit was in barring with auxiliary oil pump [AOP] in service], it was observed for one of the gas turbines that the auxiliary hydraulic oil pump [AHOP] failed to come into service. As a result of which the unit was kept in crank forced condition [Auto/Cable Remote/Start command was initially given from HMI for FSNL]. On checking the AHOP module it was found that QL [lube oil pressure adequate] switch had not energized during barring gear operation. As a result of which AHOP was not taking start command [both from Mark 5 as well as from local module start]. However, on checking Mark 5 rungs, it was found that L63QAL lube oil pressure switch adequate had got energized, & L4HQZ AHOP start command was going correctly from Mark 5. Finally, the switch was shorted from local & AHOP took start. On checking the other gas turbine also, the same hard wired logic was found. Since the AHOP takes suction from lube oil discharge header, the logic makes sense. But since this is already given from Mark 5, is a separate hard-wired logic also required? I have seen this fail safe hard-wired logic for emergency oil pump starting, but that is for saving the turbine bearings. Is it safe to remove this hard-wired logic or is it recommended by GE as additional safety for protection AHOP against dry run? Is it really required for AHOP module since the main hydraulic oil pump [shaft driven from accessory box] has no such extra protection? Is this logic incorporated in any other GE frame 9E or any other frame units?