21
5.2.6. Terminals for digital input and output to relay. Only in
models with power ratings > 3 kVA.
•
The device has a four-terminal connector for a digital input
and output to relay (see Fig. 15).
‘Start/Stop’ digital input. With the device running,
apply a sequential voltage of between 5 and 12 V DC to
reverse its state.
The static bypass function of the UPS is enabled
by default. In this condition, when the inverter
shuts down, the output terminals will supply voltage
through the internal static bypass.
Disable the bypass function through the control panel if
the output supply needs to be cut when giving the shut
down command.
Error or fault dry contact. Any error or fault will modify
the state of the normally open (NO) 24V DC 1A contact.
(PAY ATTENTION to the voltage and current applied).
– Digital input
+ Digital input
Output to relay,
error or fault
Fig. 15.
Digital input/output to relay connector.
5.2.7. Manual bypass auxiliary contact terminals. Only in
models with power ratings > 3 kVA.
•
The SLC TWIN has a signal block through which it is
possible to activate the shut down command for the UPS’s
inverter when closing the circuit. This normally open
contact is intended for connection to an external manual
bypass switch or disconnector. (see Fig. 16).
•
On the distribution boards with manual bypass that
we supply upon request, there is a two-terminal block
connected in parallel to the normally open auxiliary contact
of the board’s manual bypass switch or disconnector. The
manual bypass auxiliary contacts are of the advanced type
when closing.
•
The connection between the auxiliary contact of the board
and the UPS or UPSs is in parallel. This way, any of the
auxiliary contacts that close the circuit will activate the
shut down command of the inverter, transferring the
powering of the loads to the internal static bypass, unless
this is disabled through the control panel, in which it will
cut the powering of the loads.
•
In parallel systems, the distribution board’s manual
bypass switch or disconnector will have an auxiliary
contact block for each device.
Under no circumstances
should the different contacts be joined together as this
would connect the different earths of the control of each
UPS.
•
In the event of acquiring a manual bypass board
through another conduit, check that it has this
auxiliary contact and connect it to the terminal block of the
UPS or each device in parallel systems. The type of auxiliary
contact has to necessarily be advanced when closing.
•
It is
ESSENTIAL,
as a safety measure for the
assembly, including the loads, to connect the UPS’s
auxiliary bypass contact to the block of the same
functionality on the manual bypass board. This will prevent
any incorrect action on the manual bypass disconnector
when the UPS is running from causing total or partial failure
of the system.
This is also applicable for systems in parallel.
Fig. 16.
Terminal block for connection to the inverter shut-
down auxiliary contact of the manual bypass board.
5.2.8. Connection in parallel, only in models with power
ratings > 3 kVA.
5.2.8.1. Introduction in redundancy.
N+X is usually the most reliable power structure. N represents
the minimum number of devices that the total load needs; X re-
presents the number of redundant devices, that is, the number of
faulty UPSs that the system can simultaneously allow. The higher
X is, the greater the reliability of the system. For occasions where
reliability is essential, N+X will be the optimum mode.
Up to 3 devices can be connected in parallel to configure a
shared output or power redundancy.
5.2.8.2. Installation and operation in parallel.
•
The communications line -COM- constitutes a very
low voltage safety circuit. To preserve the quality
must be installed separately from other lines carrying
dangerous voltages (power distribution line).
•
Parallel connections and current signal bus.
Use the 15-wire signal cable with mesh and DB15
connectors at the ends to connect a maximum of 3 devices.
Each cable has a male and a female connector at the ends
which must be connected to link two devices. It is essential
to close the communications loop of the parallel bus and
the current signal bus through the cable with connectors
The length of the cables related to the parallel bus is ap-
prox. 1.5 metres and must not be prolonged under any
circumstances due to the risk of interference and communi-
cation failures that this would entail.
Communication bus.
Current signal bus
Fig. 17.
Communication and current signal connections
for system in parallel.
SLC TWIN PRO2
UNINTERRUPTIBLE POWER SUPPLY SYSTEMS (UPS)
USER MANUAL
