Document ybY9OM4vyQLr8VvkDLgObem1E

SoQ, 7h-Q2 Type 2-SC-13 Hating 75QG Ktf.@ 3&0 4<X)#-750"2n Hg*Abs. This turbine governor was originally purchased by Girdler Construction Company for Northern Chemical Industries at Searsport, Maine,, Presently, It is on a five year lease to Shametron Corporation., The generator is used to supply plant power for the neighboring northern Chem ical Industries plant and also load consumed at Chemetron0 The generator is not operating in parallel With any other power supply, only a email limited tie is maintained with Central llaine Power for limited plant operation in case of Since the original, start-up of this unit (March, 1956) there have been periods of "hunting" experienced when the electrics! load was such that the governor valves were near a cut-in position.. But due to the nature of the plant, an al most steady 7000 Kfc? has been maintained which is bout mid-way \ro on valve0 When the load forced the cam near a cut-in position, and the hunting started, customer would reduce ate pressure to change the cam position, This went on for quite a few years and with each overhaul, an attempt was mad to correct the hunt. The amplitude of -fjhe hunt was approximately ,2 cycle. The plant is presently coming out from under a very lengthy labor strike' and is presently operating at very light loads. The electrical load is approxiESitely 1000 to 1200 M3 and will jgsaaln this- way until the end of January, L9&L when the load will resume to approximately 7000 -Wt, With the light load, customer could not reduce the bunting by lowering initial pressure and called for service,, Elliott serviceman uncovered severe wear on the cam shaft journals and laat&lised the journals to sise. Also replaced the gear segment and pinion, which stewed over l/6" wear on several teeth. Several rod ends on the servo-motor linkage were replaced and the unitT placed back in service* The hunt persisted and this writer went to assist the serviceman. The unit was enured upon arrival and the earn follower assemblies 'for #1 end #2 opening valves were removed along with the valve closing springs 0 The cyosshe&a on the $1 valve had galled at <?ne time and all of the nut locking the valve stems to the crossheads were of the commercial nut variety and not of the recent design, that of a specially faced nut perpendicular to a chased thread. The nuts were ell changed, the crosshead all freed. All valves, when locked with jam nuts, were then free. The valve settings were all checked and reset to the valves as given in the instruction book. The hunting had loosened the pinned connection between th cam follower assembly and the connecting link to the orosahead on $1 sad $ valves?, bo these two crosshead were placed in #6 and itJ valves, as the turbine* has 60$ excess flow, and underplant5 heaviest load, $5 valve is still seated A few other corrections were sm.de in the servo-motor linkage aad the unit was brought up to speed December 1J?, 19^0 o It same a governor and speeds were shacked okay. After the first over-speed test, the unit came oa the governor at the minimum speed setting and proceeded to climb in peed until #1 valve was tap ped with a hammer* This brought speed down to minimum seasc. governor setting,, The servo-motor meanwhile, had over-traveled, attempting to correct the speed rise*