Transwitches

TRANSWITCH UNITS TYPE TSU UPTO 1000 KVA APPROVAL NO. 453

Flameproof transwitch units UPTO 1000 KVA AVAILABLE. Extremely compact and versatile transwitch units with transformers. The primary side of these transwitches is designed for 3300/6600 Volts. The primary side of the transwitch unit is equipped with vacuum/SF6 circuit breakers The primary side of the transwitch unit has its own set of fault sensing and protective devices and it is set to trip on any faults occurring either at the primary of at the secondary side of the transwitch. The secondary side of the transwitch is designed for dual voltage output either 550V or, 1100 Volts depending on requirement at the mine. The secondary side of the transwitch is equipped with three individual circuit breakers. Each of these circuit breakers have their own set of protective devices, to provide individual control and protection to these circuits. There is no need to keep three sets of section switches for the circuit breaking and protection. Three sets of cable couplers each rated at 300 amps are provided from these outlets for direct connection. Tap changing on the transwitch is done from a special opening on the trunking box (TRCC) between the primary circuit breaker and the transformer section. Choice of protections to the circuit are available such as, overload protection, earth leakage protection, short circuit protection. The LVCA version of the transwitch can provide upto a maximum of 3 independently operated circuit breakers in 550V or 1100Volts with individual protection and this version is mounted with R32 adaptors on the outgoing side for direct connection to the gate end box

LOW VOLTAGE CHAMBERS, APPROVAL NO. 453

Choice of either one of the versions of Secondary Cubicle can be provided : LVCA or LVCB

LVCA - In this version the following are fitted:

• 3 independent circuit breakers each circuit breaker fitted optionally with
• 1 set phase indicators
• 1no. Ammeter
• 1set HRC Fuses
• 1no. Circuit breaker with undervoltage release
• 1no. Earth Leakaeg Relay suitable for earthed or unearthed system to suit 80-mA to 750mA tripping with time delay also adjustable
• 1no. Search & Lockout Module
• 1no. BICC type FLP Straight Adaptor Type R31
• 1no. Overvoltage Protection system with instantaneous tripping to operate if voltage on secondary side exceeds 15% and IDMT characteristics for overvoltage upto a maximum of 10%. This relay will trip the HT Circuit Breaker thereby isolating the transformer unit only in case of a fault.

LVCB - In this version the following are fitted:

• CBT operated Earth Leakage Relays to suit Earthed, unearthed systems and set to trip between 80mA to 750mA with adjustable time lags
• Overload and Short Circuit Relay
• Fuse Protection of the circuit
• 3nos. Windows for Ammeter, Voltmeter and indication of earth leakage trip, short circuit trip overload trip and control on
• Overload protection set to trip at a preset value.