GE Frame 5 High Exhaust Thermocouple Reading

Dear All,

one of our GE frame 5 MS5001PA gas turbines has three of the thirteen thermocouples reading higher than normal. This is causing a high spread alarm and trips.

Thermocouples TT-XD1, TT-XD2 and TT-XD13 are reading 30-40 degrees higher than the other thermocouples. All 13 thermocouples are new and were recently installed on the unit. We suspect issues with the combustion system but having difficulty associating the thermocouples with their appropriate combustion cans so we can investigate.

What could possibly be the cause of this and how do we correct it?