OPERATION MODES

On-line Mode

DC is the primary source of supply whilst Mains (AC) works as the secondary source of supply. Switching time between DC input and AC input is 0ms (source transfer).The power delivered by the DC source (usually a battery , but it could be any other type of DC generator) is converted to provide regulated and transient free power to the load. In case of short circuit at the load side, the boost is automatically, timely and energized for a specific duration to trip downstream protective devices.

Safe Mode

Safe mode uses DC as primary source of supply while Mains (AC) is in standby. Mains (AC) is normally disconnected through internal inlet relay and is only connected when down stream clearance is required (boost) or if DC is unavailable.

The transfer between DC and AC results in typical transfer time of 10ms. Typically the safe mode is used in extremely harshed environments such as railways. Under such conditions it provides extra isolation against disturbances carried by the Mains.

EPC-mode

Mains input (AC) is the primary source whilst DC works as backup.

The TSI is designed to operate on Mains on permanent basis and to deliver output voltage conditioned with low THD. There is no physical difference on the output sine wave whether the source is AC (or) DC. If the Mains is out of tolerance or goes down, the converter seamlessly switches to DC and the converter operates in “Back-up mode” (Switching time back and forth is 0 ms). As soon as the Mains returns in to valid range, the EPC mode is automatically resumed.

The EPC mode offers higher efficiency (up to 96% depending on the model) without compromising the purity of the output sine wave.

Mix Mode & Walk-in-mode

Under some circumstances DC and AC source can be combined. The sequence is defined by a user selectable set of parameters start, control and exit are fully automatic. A specific example of Mix-mode is the Walk-in mode where the transfer from DC source to AC source is ramped up within a fix and adjustable period of time.

Setting for Walk -in -Mode and Mix Mode can be made through the T2S supervisor configuration file.

By Pass Mode

The automatic by pass is engaged in case of following condition

• AC input is present and 1 BRAVO TSI Module failure if no redundancy configured OR only one module installed OR
• AC input is present and 2 BRAVO TSI module failure if one module redundant has been configured.

The automatic by pass IS NOT AVAILABLE if:

• No AC Input is present
• AC output LOAD exceed 5kVA