IEEE 937-2019 pdf free

IEEE 937-2019 pdf free.IEEE Recommended Practice for Installation and Maintenance of Lead-Acid Batteries for Photovoltaic (PV) Systems.
For the purposes of this document, the following terms and definitions apply. The IEEE Siandarth Dklionwy Online should be consulted for terms not defined in this clause.
battery capacity: The quarnity of electrical energy, measured in ampere-hours or watt-hours, produced by a battery during discharge.
d r-chargcd cell: A cell that has been assembled with its plates dry. and in a charged state, ready to be activated by the addition ofelectmlyte and charging.
equalizing voltage: A charge, at a level higher than the normal float voltage, applied for a limited period of time, to correct inequalities of voltage, specific gravity, or state of charge that may have developed between the cells during service.
freshening charge: A charge given to a battery following its nonuse or storage in order to return it to a near maximum state of charge and to mitigate the effects of self-discharge.
NOTE Freshening charges are sometimes perfonned using the manufacturer’s recommended equalization or cycle service charging voltage.
life: The period during which a battery is capable of delivering at least a specified percentage of its rated capacity, ofien 80%. See also. service life.
pilot cell: A cell chosen to represent the operating parameters of the entire battery ora subset of the battery.
NOTE— Multiple pilot cells may be used. rated cipacily: The capacity assigned to a cell by its manufacturer for a given discharge rate, at a specified electrolyte temperature, to a given end-of-discharge voltage.
service life: The period of useful operation under specified conditions, usually expresscd as the time period or number of cycles that elapse before the ampere-hour capacity falls to a specified percentage of the rated capacity.
valvercgulated lead-acid cell (VRLA): A lead-acid cell that is sealed with the exception of a valve that opens to the atmosphere when the internal gas pressure in the cell exceeds the atmospheric pressure by a preselected amount. Valve-regulated cells provide a means for recoinbination of internally generated oxygen and the suppression of hydrogen gas evolution to limit water consumption.
vented cell: A cell in which the products ofelectrolysis and evaporation are allowed to escape to the atmosphere as they are generated. Stia. flooded cell.
NOTE— I’nted cell is the preferred term that should be used in place of we: cell or flooded cell.
4.1 Introduction
The safety practices of the battery manufacturers and suppliers and those listed herein should be followed during battery installation and maintenance. Work performed on batteries shall be done with the proper tools and protective equipment. Battery installation shall be performed or supervised by personnel knowledgeable of batteries and the required safety precautions. Keep unauthorized personnel away from batteries.
4.2 Protective equipment
In some cases, equipment requirements are different for vented lcad-acid(VLA)banerics and valve-regulated lead-acid cell (VRLA) batteries. The following cquipmen is recommended for safer handling of lead-acid batteries and protection of personnel:
a) Full eye protection, such as goggles or a face shield (safety glasses for VRLA)
b) Protective clothing, including acid-resistant gloves. aprons. and overshoes (VLA only)
C) Portable or stationary safety shower and eyewash stations(both for VLA; eyewash only for VRLA)
d) A suitable acid-neutralizing agent. such as bicarbonate of soda haking soda)
e) A lifting device of adequate capacity
0 Adequately insulated tools
g) A Class C’ fire extinguisher (CO-typc extinguishers should not be used because of the potential thermal shock to batteries)
4.3 Safety procedures
4.3.1 Introduction
The following arc hazards inherent in the use of lead-acid batteries and the recommended related procedures to help ensure safety. In addition. NFPA 70E [116]4 identities arc-flash hazards for dc voltages above 100 V. Most systems covered by this document have a nominal de voltage of 48 V. for which no arc-flash protective equipment is required. A discussion of ait-flash hazards fordc voltages above 100 V is included in IEEE Std4X4’’ 1112].
4.3.2 Electrolyte hazards
The electrolyte is a sulfuric-acid solution that is harmful to the skin, eyes, and internal organs. It is corrosive and electrically conductive. The following procedures should be followed when handling the battery and electrolyte:
a) Wear full eye protection and protective clothing.
b) If electrolyte contacts the skin, wash it off immediately with water.IEEE 937 pdf download.