Battery Charger; Working Principle - Xtender XTS 900-12 User Manual

Studer Innotec SA
Xtender
In the case of mobile applications, the installation of an RCC-02/-03 remote control is
recommended in order to be able to adapt the value of the input current limit if necessary,
for each connection to a limited grid.
7.2.2.4 Deactivation of the source assistance function (Smart Boost)
This feature the source current assistance "smart boost" can be disabled by setting {1126}.
The remote RCC-02/03 is necessary to disable the function on the model XTH and XTM. On the XTS
model, it is possible to disable it by selecting the slide button (19) in OFF position.
7.2.2.5 Automatic reduction of the current limit input
When the device is connected to a low power generator, most often, the voltage of the generator
falls down before its rated power. To compensate partially this side effect, the Xtender has a system
of automatic reduction of the input current limit, if the voltage drops beyond a threshold set by the
parameter {1309}+ {1433}, to fall to zero when it reaches the value set by parameter {1309}. This avoids
overloading the generator and too frequent transition of the transfer relay.
This feature is also used when a variable power source is connected to the input of the Xtender. This
is particularly the case of 230 Vac alternators type "Dynawatt" coupled to drive motors whose speed
varies. These devices have their source voltage decrease depending on the available power. A
correct setting of thresholds {1309} and {1433} ensures continuous power output with the "Smart Boost"
This feature can be disabled by setting the {1527} especially when the Xtender is connected to a
public network.
7.2.2.6 Setting the current "Input limit"
The maximum input current can be adjusted by the knob (18) on the XTS or via remote control RCC-
02/03 on other models or on the XTS with the module TCM-01. The parameter {1107} is part of the
basic parameters of the device and must be adjusted at commissioning (see sect. 5 - p. 24)
depending on the capacity of the source as follows:
• If the device is connected to a network: the value is sized according to the upstream protective
device (fuse or circuit breaker) or a lower value if desired.
• If the device connected to a generator, the following empirical formula can be used:
Generator power below 1 kW: 0.7 x Pnom / Uac
Generator power below 3 kW: 0.8 x Pnom / Uac
Generator power above 3 kW: 0.9 x Pnom / Uac
Given the wide divergence of performance and quality of available generators on the market,
these formulas are approximate and are not a guarantee of proper adjustment of the installation.
7.3 B
ATTERY CHARGER

7.3.1 Working principle

The battery charger for the Xtender is completely automatic and is designed to guarantee an
optimum charge for the majority of lead-acid or gel batteries. Once the transfer relay is activated,
the battery charger goes into operation and the charge indicator (44) lights up.
The charging process has three levels (I/U/Uo) as described in figure below.
This process guarantees optimum charging of the batteries. The charging current is given by the
parameter {1138} and can be adjusted continuously from zero to the nominal value with the help of
the RCC-02/-03 or with the rotating knob (16) inside the model XTS (see sect. 5.1 – p. 24). All times
and thresholds can be adjusted with the remote control unit RCC-02/03.
If the battery voltage is lower than the critical disconnection threshold {1488}, operation of
the charger will be automatically prevented. Only the transfer relay is authorised to operate
in this case. The battery must then be recharged by an external source up to a voltage
higher than the critical disconnection threshold in order to allow the Xtender charger to
operate.
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