BATTERY BANK PROBLEM FOR GE TURBO GENERATOR

  • Thread starter MUHAMMAD KASHIF IDREES
  • Start date
M

Thread Starter

MUHAMMAD KASHIF IDREES

WE HAVE C&D MAKE 200 AMPERE HOUR LEAD CALCIUM BATTERY BANK INSTALLED AT OUR POWER GENERATION FACILITY. The battery bank is of 130 vdc capacity comprising of 19 units each of 6 volts output. This bank is used for field flashing.

We have experienced problem in 120 VDC battery bank of one of our two Gas Turbine Units. Our Turbines are of GE make, Model 5001P, Turbine Serial Nos. 281817 & 281818. The batteries are of Lead Calcium type of C&D make and were replaced back in 1996. We have conducted load test of the batteries and have been found exhausted requiring replacement. Delivery period of similar new batteries is around 16 to 20 weeks.

We are considering installation of Lead Acid batteries, readily available in local market, as an interim arrangement to ensure smooth operation of turbines with battery back-up. Your advice is requested in this respect.
 
B

Bob Peterson

I used to do a fair amount of work on equipment that went into power plants. I was always surprised at how many plants had replaced their original 120VDC battery stacks with marine or auto type lead acid batteries.

--
Bob
 
Lead-acid, lead calcium are both lead acid batteies.

calcium is added to the lead to strengthen the plates in vehicle applications (they are the cheapest to purchase), stationary batteries and marine batteries do not use calcium as it tends to reduce battery life but they are more expensive.

Lead calcium batteries are used where you need high surge currents as in automobile starting, marine batteries where you need long life and ampere-hour capacity.

they all require continual maintenance and over-sight not just "trickle charging"
 
Most GE-design heavy duty gas turbines use (nominal) 125 VDC batteries for more than just field flashing. They are typically used for powering the Speedtronic turbine control panel including 125 VDC solenoids powered through the Speedtronic panel, emergency DC lighting, and for powering any DC emergency pumps (Lube Oil, Seal Oil, Hydraulic Ratchet, etc.). Sometimes the battery is also used for powering the fire detection/protection system, and sometimes the battery is also used for powering protective relays used for transformers and breakers for generator drive applications.

When purchasing batteries of any type, one needs to purchase a configuration that provide the required amp-hour capacity, at least equal to or slightly greater than the those originally supplied with the unit.

The specific type of battery is not critical, as long as the amp-hour rating is sufficient to provide the power required to protect the turbine during a loss of power for lube oil/seal oil pumps during a trip or shutdown to protect the bearings/seals until the unit can get to zero speed. Some capacity should also be available to continue to power the Speedtronic while at zero speed to sequence the cooldown scheme (e.g., hydraulic ratchet) for some period of time.

I believe the packager chooses batteries primarily based on capacity, price, and longevity. I've seen lead-acid batteries that were properly maintained last 30+ years.

Work with your vendor to choose a battery that meets the criteria above, and then read and understand the manufacturer's instructions and recommendations for maintenance and optimizing battery life and you should be very happy with your choice.

Also, make sure the battery you choose is compatible with the charger you have.
 
Top