GE 7FA.05 - Scanner Lens; Speed Control and Overspeed Protection System (Electronic); Magnetic Pickups; Calibration Checks

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Inspection and Maintenance Instructions for 7FA.05 Gas Onl

and Dual Fuel Gas Turbine

GEK 116862

B. Scanner Lens

The scanner lens should be cleaned with a dry cloth as often as necessary on a regular schedule. No

repair of any sort should be attempted on the scanner, or switch assembly. If damaged, or defective, it

should be replaced and returned to the factory.

Refer to the Control Specification — Control System Adjustments for testing of flame detectors with

the unit in operation. Refer to the Control Specification for logic signal output explanation.

XXIII. SPEED CONTROL AND OVERSPEED PROTECTION SYSTEM (ELECTRONIC)

A. Magnetic Pickups

The clearances between the OD of the toothed wheel and the tip of the magnetic pickup should be

checked annually and at each removal and installation. The clearances should be within the limits

specified in the Device Summary.

B. Calibration Checks

These calibration (continuity) checks of the overspeed protection system should be performed

annually and after each major inspection, or at any time wiring has been disconnected.

XXIV. SPEEDTRONIC* CONTROLS AND EQUIPMENT

A. Control Panels, Junction Boxes, and Power Supply Components

Any indication of corrosion or discoloration, due to heat, should be investigated and the equipment

repaired or replaced as necessary.

In atmospheres that contain contaminants, such as hydrogen sulfide, sulfuric acid, sulfur dioxide,

chlorine, and chlorine dioxide, the relative humidity of the SPEEDTRONIC* control panel location

should be maintained at 50 percent or less to minimize any possible corrosion problems. Conformal

coatings are used to protect electronic equipment; however, high relative humidity can cause

accelerated corrosion in any area not properly protected.

Refer to SPEEDTRONIC* Maintenance Manual Procedures.

B. Relay Contacts

Relay contacts within the Mark* VIe are not serviceable. Failed relays shall be replaced.

XXV. INLET AIR SYSTEMS (TURBINE)

A. Inlet Filter House

The inlet screens or mist eliminators shall be checked for any foreign object obstructions monthly.

Refer to Inlet Filter House system and manufacturer’s recommendations in Air Inlet and Exhaust

System in the Operation and Maintenance Manual.

B. Inlet Duct and Plenum

Inlet trash screen shall be inspected for any foreign material annually.

Refer to Inlet Duct and Plenum section of the Operation and Maintenance Manual.