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SALICRU
5.4. How to replace a faulty UPS in a
parallel system.
Press over the key in any UPS for more than 3 sec-
onds to shutdown all the inverters. The acoustic alarm
will beep for 3 seconds. The equipments that belong to
the current parallel system will transfer to "Bypass mode".
Put all the equipments on manual bypass. To do it re-
move the cover from manual bypass switch, which is
located at the back of each equipment and turn all the
switches to position "BYPASS".
Keep in mind that on "Bypass mode" or with the
switch on position "BYPASS", the loads will be
exposed to fluctuations of voltage, frequency and mains
faults or blackouts, so in case it were possible choose
one day with the lowest probability of faults (days without
fluctuations, days without storms,... ) and do it as fast as
possible.
Turn "Off" the input, output and bypass circuit breaker
protections (this last one when it is available) from the
protection panel and corresponding to the equipment to
replace.
Disconnect the communication bus and all power con-
nections, and remove it. In equipments installed as rack,
remove the screws that fix it to the cabinet previously.
Put the manual bypass switch of the new UPS, to position
"BYPASS". To do it remove the protection cover of the
manual bypass located in the rear side and act over itself.
Put the new equipment that replaces the faulty one and
reconnect it. Follow the instructions stated in section
4.3.9.2, to connect them in parallel.
For equipments installed as rack, put the screws that fix it
to the cabinet previously.
Ŗ
Turn "On" the input and bypass circuit breakers (this last one,
if it is available) from protection panel, and corresponding to
the new UPS.
UPSs supply output voltage from bypass. Check the LCD
screen from control panel in case there were any warning or
error information.
Measure the output voltage of the new UPS, check the
voltage difference is below 1 V. In case the difference were
higher than 1 V, double check the wiring and associated in-
structions.
Ŗ
Put back the cover of the manual bypass of each UPS.
Ŗ
Press over the start up key for more than 3 sec. in any of
the UPSs and all of them will start up. All UPSs will transfer
to "Normal mode”.
Measure the output voltage in the power blocks of the parallel
system and the output terminals of the new UPS, to check
the voltage difference is under 0,5 V. In case the difference
were higher than 1 V, the UPSs have to be set (contact with
the S.T.S.).
Ŗ
Press over the shutdown key in any UPS for more than 3
seconds and each one will be shutdown, supplying output
voltage through the bypass.
Turn “On” the output circuit breaker switch of the distribution
panel, corresponding to the new integrated equipment. The
complete parallel system will supply output voltage, through
the bypass.
Ŗ
Remove the cover of the manual bypass in each UPS.
Ŗ
Transfer the equipments with the manual bypass ("BYPASS"
position) to position "UPS". Do it in the switches of all equip-
ments.
Ŗ
Put back the protection cover of the manual bypass switch
of all equipments, also check the torque of the fixing screws,
otherwise any of the limit contacts of this cover could be acti-
vated and the manual bypass too.
Ŗ
Press over the start up key for more than 3 sec. in any
of the UPSs and all of them will start up, finally the parallel
system will be working on "Normal mode”.
Load/s are running and protected by the parallel system
again.
5.5. Manual Bypass Switch
(maintenance).
5.5.1. Operating
principle.
Integrated manual bypass in all UPS from
SLC TWIN RT from
4 to 10kVA
is very useful, but a wrong use can cause irrevers-
ible consequences for both the UPS and connected loads at its
output. Therefore, it is important to respect the manoeuvring over
the switch as it is stated in the following sections.
5.5.2. Transference to maintenance
bypass.
Ŗ
The procedure to transfer from normal mode to maintenance
bypass is the same for a single equipment or a parallel
system, less the quantity of actions:
For a single equipment.
–
Press over the key of the UPS for more than 3 sec-
onds to shutdown the inverter. The acoustic alarm will
beep for 3 seconds. The equipment will transfer to
"Bypass mode".
For a parallel system.
–
Press over the key in any UPS for more than 3
seconds to shutdown all the inverters. The acoustic
alarm will beep for 3 seconds. The equipments that
belong to the current parallel system will transfer to
"Bypass mode".
Put all the equipment/s on manual bypass. To do it re-
move the cover from manual bypass switch, which is
located at the back of each equipment and turn all the
switch to position "BYPASS.
In parallel systems, proceed in the same way in each
equipment.
Keep in mind that on "Bypass mode" or with the
switch on "BYPASS" position, the loads will be ex-
posed to fluctuations of voltage, frequency and mains faults
or blackouts, so in case it were possible, choose one day
with the lowest probability of faults (days without fluctua-
tions, days without storms,... ) and do it as fast as possible.
The UPS still supplies output voltage, from mains directly
or through the static bypass line (in those installations
that it is available), through the manual bypass of the
equipment.
Also, if the protection panel has manual bypass switch,
remove the mechanical lock and turn the switch "On"
(BYPASS).
In this case and in this case only, turn the output
switch/es from distribution panel to
"Off", depending
if there is only one UPS or a system of two equipments
in parallel.
