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Tuesday, March 29, 2011

Low Specific Gravity of cells of 125 VDC Battery Bank

I. Background of the Problem:
March 24, 2011
a. The Substation Engineer-on-duty conducted monthly testing of station batteries. Our 125 VDC Battery Bank is composed of sixty lead acid battery cells. Battery testing include voltage, temperature and specific gravity measurements for the 125 VDC, 48 VDC and 12 VDC battery cells.
b. He noticed that the specific gravity of some cells of 125VDC battery bank 1 were below the normal value which is 1.215. He then put 125 VDC Battery Bank 1 to equalizing charge for 24 hours.

Tuesday, March 22, 2011

lead-acid battery explosion and prevention

Battery bank of power substation is very critical since it serves as standby power supply for the high voltage equipment and its relays to be operated so that power can be restored in case of massive blackout or total loss of power. Lead-acid batteries are the most common type of batteries used in substation battery banks. Advantages include the ability to supply high surge current, large power to weight ratio, relatively cheap, easy maintenance and long useful life.Hence, maintenance of battery banks are conducted monthly to ensure its effective and reliable operation.

Sunday, March 13, 2011

power bill rates computation: customer billing sample

Below is the sample computation of a non-firm customer with motor loads. I will not include the taxable service, non-taxable service and franchise tax computations so that power bill computations will be presented as simple as possible. There are also other charges that are not included like the metering charge, force majeure charge, power factor adjustment charge, the reactive power support charge, and universal charges.

Saturday, March 12, 2011

Sample Applicable Power Service and Ancillary Rates

Just to share the sample ancillary Rates for the Billing month of February 2011, please search the internet for real-time ancillary rates given by the utility providers. Please use the table as reference guide only. The rates are subject to change without prior notice.