51
R
EMOTE MAINTENANCE
B
YPASS
An additional maintenance bypass may be installed within (or in addition to) the main switchboard, for example, to enable the UPS to
be replaced without interrupting the power supply to the load, in this case respect the following details:
It is mandatory to connect the "SERVICE BYPASS" terminal (see the “Installation Manual”, "Programmable IN
– OUT signals" paragraph) to the NC auxiliary contact of the SERVICE BYPASS switch. Closing the SERVICE
BYPASS switch opens this auxiliary contact which informs the UPS that the maintenance bypass has been
activated. If this connection is not present, the power supply to the load may be switched off and the UPS
damaged.
NOTE
:
Use cables with a cross sectional area that conforms to the indications given in "POWER CONNECTION INFORMATION"
paragraph of the Installation manual.
Use a double insulated cable with a cross section of 1mmsq to connect the "SERVICE BYPASS" terminal to the auxiliary
contact of the remote maintenance bypass disconnect switch.
Whenever the UPS is equipped with an internal isolation transformer, check the compatibility between the
“remote
maintenance bypass”
and the neutral arrangement within the electrical installation.
DIAGRAM SHOWING REMOTE INSTALLATION OF THE MAINTENANCE BYPASS (USS3T MODEL)
Main switchboard
Internal connections of the UPS
Programmable IN/OUT port (to be configured via the configuration software)
INPUT switch: for correct sizing refer to the "Internal Protective Devices” paragraph
OUTPUT switch: for correct sizing refer to the "Internal Protective Devices” paragraph, equipped with a normally closed
auxiliary contact
SERVICE BYPASS switch: for correct sizing refer to the "Internal Protective Devices” paragraph, equipped with a normally
closed auxiliary contact
