_Generator Gas Monitor System for the early detection by joshcorey



GE Power Systems

Protect Against Forced Outages With GE’s Generator Gas Monitor System

Pyrolysate Collector


Core Monitor
Early and accurate detection of insulation material overheating in generators is the key to finding problems before they turn into a costly forced outage. The GE Generator Gas Monitor System (GGMS) has been providing this kind of protection for hydrogen-cooled generators for over 30 years. The present design blends the proven method of detection with the reliability and accuracy of a microprocessor-based system. The GE GGMS is a combination of a Controller Panel, Core Monitor, and a Pyrolysate Collector. The GE GGMS is the most advanced monitor on the market today. Data Logging The recorder samples incoming analog data many times per second. Data is recorded to the removable memory card. The system can store more than 7 years of data. The system also has Ethernet, ModBus, and a 4-20mAoutput signal available. Enamels, and many other insulating materials commonly found in today’s generators. check the total performance of the system. The system also has had an Off Speed input signal option added to the Controller unit. This eliminates the "Monitor Malfunction Alarm" that accrues if the Generator is not at full speed and no generator gas is flowing to the Core Monitor. The Core Monitor will indicate that the system is normal but a message on the Controller display will indicate that the generator is not up to speed. The Core Monitor unit will go back on line when the generator is back at full speed. The automatic Pyrolysate Collector also has an updated stainless steel chamber. The sampling system has two filters that will collect two samples of the Pyrolysate products used for laboratory analysis.

The Core Monitor contains an ionization chamber with a weak alpha radiation source arranged to generate an ion current flow across a stream of hydrogen drawn from and returned to the generator. When sub-micron particles of the type produced by thermal decomposition of insulation are present in the gas stream, the current flow is reduced when these particles attach themselves to the ionized hydrogen atoms. The reduction of current is a measure of the extent of the overheating. This output current is continuously recorded and activates an alarm system when it drops below a specified value. CORE MONITOR FEATURES The system is completely stainless steel and has been updated for longer life and lower maintenance. The system has an automatic alarm verification system along with a selftest function that activates a systems test device that will produce smoke to

What Will It Detect?
The Core Monitor is sensitive to the thermal decomposition of materials like: Epoxy Paint, Core - Lamination GEA-12643 (1/03, 5M)






60 % ALARM 70 % ALARM

Generator Gas Monitoring System.
The Maintenance-free operation is accomplished by using a stainless steel chamber that is heated to 155 Deg C to eliminate the affect of oil or water contamination in the gas stream. This is accomplished with no loss of sensitivity in the detection of pyrolysates from overheated generator materials. The heated chamber also eliminates the need for Oil/Moisture traps that could actually lower the sensitivity of the instrument.

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Benefits of the new GGMS
• • • • • Microprocessor-based system. Digital Communication Eliminate Noise. Only Two RS232 Cables Used For All The Control Signals. Controller Displays A Status Line. Warning and Trouble Indicators.

Data is recorded to a removable memory card. Ethernet Communication available. ModBus Communication available. Remote Control of Ion Chamber and Pyrolysate Collector. Simple Installation Maintenance-Free Operation. ETL certified

at a reduced price in exchange for his old outdated Core Monitor. The new exchange GGMS would be shipped to the customer site and would be installed by the customer or PGSD at the next available outage, so that the generator would not have to be operated without a core monitor in operation. Then after the installation has been completed the customer would be responsible for shipping his old Core Monitor back to GE Schenectady. There is also more information available on product costs from GE Power System Sales & Services representative or from:

Exchange Program
The core monitor exchange program was developed to help customers take advantage of the latest digital controlled Generator Gas Monitor system (GGMS) available. The core monitor exchange program gives the customer a Gas Monitoring System which includes the Control Panel, Core Monitor, and the Pyrolysate Collector

GE Life Extension Services Bldg. 55, RM. 263 1 River Rd. Schenectady, NY 12345 Phone (518) 385-5654

GEA-12643 (1/03, 5M)

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