12.10.2 ApplicationUsually, the load on the DC system is a constant resistance load, for example, lamps,LEDs, electronic instruments and electromagnetic contactors in a steady state condition.A transient RL load exists when breakers are tripped or closed.The battery voltage has to be continuously monitored as the batteries can withstandmoderate overvoltage and undervoltage only for a short period of time.• If the battery is subjected to a prolonged or frequent overvoltage, it leads to the ageingof the battery, which may lead to the earlier failure of the battery. The otheroccurrences may be the thermal runaway, generation of heat or increased amount ofhydrogen gas and the depletion of fluid in case of valve regulated batteries.• If the value of the charging voltage drops below the minimum recommended floatvoltage of the battery, the battery does not receive sufficient charging current to offsetinternal losses, resulting in a gradual loss of capacity.• If a lead acid battery is subjected to a continuous undervoltage, heavy sulfationoccurs on the plates, which leads to the loss of the battery capacity.12.11 Insulation gas monitoring function SSIMG (63)12.11.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberInsulation gas monitoring function SSIMG - 6312.11.2 ApplicationInsulation gas monitoring function (SSIMG ,63) is used for monitoring the circuit breakercondition. Proper arc extinction by the compressed gas in the circuit breaker is veryimportant. When the pressure becomes too low compared to the required value, the circuitbreaker operation gets blocked to minimize the risk of internal failure. Binary informationbased on the gas pressure in the circuit breaker is used as input signals to the function. Inaddition to that, the function generates alarms based on received information.Section 12 1MRK 511 286-UUS AMonitoring306Application manual
