User Manual
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4.4 AC connection
A three phase AC breaker needs to be installed on the AC side of the WTS 25-50K. Select a proper overcurrent
protection device in compliance with local power distribution regulations and Max to ensure that the WTS 25-50K can
safely disconnect itself from the power grid when an exception occurs. Input (output) current of WTS 25-50K AC side.
The allowable AC cable of wire diameter and cross-sectional area for Wattsonic WTS 25-50K are as shown in the
following:
Wir
e Diamete
r
20-30mm
Cross-sectional Area
10-25mm (Flexible cable)
10-35mm (Hard cable)
2
2
4.4.1 AC side requirements
Note
: 1) An independent AC breaker is required in both the on-grid and backup output sides, and any loads
cannot directly connect with the inverter.
2) Please confirm that all DC & AC power sources are disconnected from the inverter before connecting the
AC cable.
3) The Wattsonic WTS 25-50K series three-phase high voltage hybrid inverter applies to the three-phase
power grid with a voltage of 230/400V and a frequency of 50/60Hz.
4) Connect the inverter to the grid only after getting approval from the local electric power company.
Note
: Determine whether an AC circuit breaker with greater overcurrent capacity is required based on
actual conditions.
With an integrated universal current-sensitive residual current monitoring unit, the inverter will disconnect immediately
from the mains power once a fault current with a value exceeding the limit is detected.
However, if an external residual current device (RCD) (type A is recommended) is mandatory, the switch must be
triggered at the residual current. RCD of other specifications can also be used according to local standards. The
recommended residual current is as follows.
Residual current monitoring device
Inverter Recommended residual current
WTS-25K-100
WTS-30K-100
WTS-36K-100
WTS-40K-100
EWTS-40K-100-P
WTS-50K-100
WTS-50K-100-P
300mA
360mA
400mA
500mA
