ABB REL650 series, Applications Manual

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14.10.2 Application
Usually, 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 withstand
moderate 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 ageing
of the battery, which may lead to the earlier failure of the battery. The other
occurrences may be the thermal runaway, generation of heat or increased amount of
hydrogen gas and the depletion of fluid in case of valve regulated batteries.
• If the value of the charging voltage drops below the minimum recommended float
voltage of the battery, the battery does not receive sufficient charging current to offset
internal losses, resulting in a gradual loss of capacity.
•
If a lead acid battery is subjected to a continuous undervoltage, heavy sulfation
occurs on the plates, which leads to the loss of the battery capacity.
14.11 Insulation gas monitoring function SSIMG (63)
14.11.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Insulation gas monitoring function SSIMG - 63
14.11.2 Application
Insulation gas monitoring function (SSIMG ,63) is used for monitoring the circuit breaker
condition. Proper arc extinction by the compressed gas in the circuit breaker is very
important. When the pressure becomes too low compared to the required value, the circuit
breaker operation gets blocked to minimize the risk of internal failure. Binary information
based on the gas pressure in the circuit breaker is used as input signals to the function. In
addition to that, the function generates alarms based on received information.
Section 14
1MRK 506 334-UUS A
Monitoring
450
Application manual