Continuous availability of auxiliary DC supply is a prime requirement for continuity of AC Power transmission and distribution as well as safe guard of major power equipment.
DC supply is being utilized for functioning of switchgear and protective relays in the power generating station, transmission and distribution sub-station, traction substation and large infra installations.
The reliable source of DC Power is normally from a battery bank without earthing of positive / negative polarity, moreover the supply cables from battery bank to equipments are being distended over a large area and passes through the trenches.
There are always a possibilities of leakage path being created due to weakness / damage of insulation or end conductor’s contact between:
Positive conductor to Earth, or / and Negative conductor to Earth
The leakage path may cause undesirable switching of circuit breakers and malfunctioning of protective relays. This condition may require an emergency outage of a substation element and may affect the HT power supply seriously.
CMSDCL is a unique device and pre-emptive approach, to eliminate the possibilities of above fault conditions through incremental value of leakage current and simultaneously alarming on initiation of minor weakening of insulation moreover the whole DC system remains in service i.e., without any outage/shutdown.
