Salicru SLC CUBE4, User Manual

21

ristors) to the booster input, and this converter will be discon-

nected from the AC input (except for hybrid operating modes).
In terms of charging the batteries, this will occur when the UPS 

is working in normal mode (AC voltage network present, AC/DC 

rectifier operating). The UPS has a reducer converter ("buck"), 

which is supplied by the DC bus voltage, adjusting it to the re-

quired levels for charging the batteries. This battery charging 

includes 2 basic stages, or even 3 (depending on the type of 

battery):

•

Constant current

: if the set charge current is not exceeded, 

the output voltage of the charger will be dynamically ad-

justed to achieve this allocation.

•

Constant voltage

: once the battery floating voltage is 

reached, the charge current will decrease. This floating 

voltage must be maintained in normal mode, a voltage that 

will be readjusted depending on the temperature.

•

Quick charge or "boost" voltage

: depending on the type of 

battery (chemistry), an intermediate stage can be config-

ured, after charging at constant current and before allo-

cating continuous float voltage, which consists of supplying 

the batteries with a voltage that is higher than the floating 

voltage for a limited time, in order to obtain a quicker and 

more efficient recharge.

The architecture of the charger is based on a double reducer 

converter: from positive and negative semi-buses, positive and 

negative battery charge voltages and currents are obtained. 

The switching of the charger's IGBTs also consists of a PWM 

controlled digitally by DSP. 
The charger incorporated as standard in the units allows the 

batteries to be recharged for both standard autonomy and for 

extended autonomy (greater capacity in Ah installed).

4.4.5.  Static bypass

The static bypass switch allows the load or loads to be switched 

between the inverter and the emergency (or bypass) network, 

and vice versa, without interruption. This bypass line may or 

may not be common to the rectifier AC input.
The switching of the output load to the bypass line can be or-

dered manually, or it can be activated by the UPS automatic con-

trol in certain emergency situations.
As power switching elements, it uses thyristors (SCR) and re-

lays. Thyristors for connecting/disconnecting the voltage of the 

bypass line to the loads, relays for connecting/disconnecting 

the inverter voltage.

4.4.6.  Manual or maintenance bypass

The manual bypass is used to isolate the UPS from the input 

voltage and loads, supplying the load directly from the input 

network in the event of maintenance or serious faults. 
It consists of a switch, supplied as standard and integrated in 

the unit, which allows the bypass or emergency line voltage 

(common to the rectifier AC input, or not) to be connected 

directly to the output, by simply activating this switch and 

without the intervention of a converter or controlled electronic 

device. Just an auxiliary signal will notify the UPS control that 

this switch is activated.

The manual bypass switch supplied in the unit has a mechan-

ical lock that makes it impossible for it to be activated acciden-

tally by unqualified staff.

External manual bypass 

In addition to the standard internal manual bypass, it is also 

possible to optionally install an external manual bypass.

4.5.  OPERATING MODES

The UPS "standby" or stopped status is where the UPS is pow-

ered but with the converters completely stopped, for various 

reasons:

•

Before initial start-up.

•

By command or manual request.

•

Due to a lock alarm that forces this situation.

The UPS will supply bypass voltage to the output (to the loads), 

even when it is completely stopped, if the input switch (or sepa-

rate bypass switch, if applicable) and the output switch are ac-

tivated (set to ON). In this situation, the unit's rectifier, charger 

and inverter will not be working. See 

Fig. 13.

From this "standby" status, the UPS can begin to work in dif-

ferent operating modes, which can be reached automatically 

or forced by a manual action of the operator. These operating 

modes, described in detail in subsequent sections, are as fol-

lows:

•

Normal mode.

•

Battery mode (autonomy mode).

•

Bypass mode.

•

Maintenance bypass mode.

•

ECO mode.

•

Frequency converter mode.

SLC CUBE4

  - UNINTERRUPTIBLE POWER SUPPLY SYSTEM 

-

USER MANUAL