Victron energy MultiPlus 12/3000/120 – 50 Manual page 19

4.3 Connection of the AC cabling
The MultiPlus is a safety class I product (supplied with a ground
terminal for safety purposes). Its AC input and/or output terminals
and/or grounding point on the outside of the product must be
provided with an uninterruptible grounding point for safety
purposes.
The MultiPlus is provided with a ground relay (relay H, see appendix B)
that automatically connects the Neutral output to the chassis if no
external AC supply is available. If an external AC supply is provided,
the ground relay H will open before the input safety relay closes. This
ensures the correct operation of an earth leakage circuit breaker that is
connected to the output.
In a fixed installation, an uninterruptable grounding can be secured by
means of the grounding wire of the AC input. Otherwise the casing
must be grounded.
In a mobile installation (for example, with a shore current plug),
interrupting the shore connection will simultaneously disconnect the
grounding connection. In that case, the casing must be connected to
the chassis (of the vehicle) or to the hull or grounding plate (of the
boat).
In case of a boat, direct connection to the shore ground is not
recommended because of potential galvanic corrosion. The solution to
this is using an isolation transformer.
The terminal blocks can be found on the printed circuit board, see appendix A. The
shore or mains cable must be connected to the MultiPlus with the aid of a three-wire
cable.
- The AC input cable can be connected to the terminal block "AC–in".
The AC input must be protected by a fuse or magnetic circuit breaker rated at
50A or less, and cable cross-section must be sized accordingly. If the input AC
supply is rated at a lower value, the fuse or magnetic circuit breaker should be down
sized accordingly.
- The AC output cable can be connected directly to the terminal block "AC-out".
With its PowerAssist feature the MultiPlus can add up to 5kVA (that is
3000 / 120 = 25A) to the output during periods of peak power requirement. Together
with a maximum input current of 50A this means that the output can supply up to
50 + 25 = 75A.
An earth leakage circuit breaker and a fuse or circuit breaker rated to support
the expected load must be included in series with the output, and cable cross-
section must be sized accordingly. The maximum rating of the fuse or circuit
breaker is 75A.
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