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M
ANUAL BYPASS
The manual bypass enables the user to physically connect the UPS input directly to the output. This condition is required to perform
maintenance operations on the UPS without the need to disconnect the power from the protected load.
This is achieved by operating the Manual Bypass switch, either within the UPS (if the UPS is endowed with internal maintenance
bypass – “SW” version only) or the external manual bypass switch. In this case, follow the prescriptions contained in the “Remote
maintenance bypass" paragraph.
When the locking pad is removed from the internal manual bypass switch handle, or the external manual bypass is operated, an
auxiliary contact informs the UPS that the load is going to be transferred to manual bypass. This activates an immediate, synchronized
transition to the internal static bypass to ensure a safe closure of the manual bypass power contacts.
WARNING: Maintenance work inside the UPS is to be performed exclusively by qualified staff. There may be
voltages present within the UPS even when the input, output and battery disconnectors are open. Removal of
the UPS panels by non-qualified staff may result in injury to the operator and damage the equipment.
For further instructions in relation to the manual bypass function, please refer to the “Switching the system to manual bypass” chapter.
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FEED PROTECTION
The UPS has an internal protection against back-feed. This protection acts by means of a sensing circuit which turns off the inverter
if a fault within the static switch is detected. In this condition, to avoid interrupting the supply to the connected load, the UPS switches
to bypass line.
If the bypass is not available, the connected load is switched off.
To avoid stopping the inverter, a dry contact can be configured to drive a disconnection device. This device must be installed upstream
of the bypass input to the UPS, in this case when a back-feed fault occurs, the system opens the external disconnection device (for
further information, refer to the configuration software manual).