Optional Connections - Victron energy MultiPlus 24/5000/120 Manuel

4.4 Optional Connections

A number of optional connections are possible:
4.4.1 Second Battery
The MultiPlus has a connection for charging a starter battery. For connection see Appendix A.
4.4.2 Voltage Sense
Two sense wires may be connected to compensate possible battery cable losses during charging. Use wires of at least 0.75mm 2 . For
connection see Appendix 0.
4.4.3 Temperature Sensor
The temperature sensor supplied with the product may be used for temperature-compensated charging (see Appendix A). The sensor is
isolated and must be mounted on the batteries minus pole.
4.4.4 Remote Control
The product can be remotely controlled in two ways.
- With an external switch (connection terminal L, see appendix A). Operates only if the switch on the MultiPlus unit is set to "on".
- With a Multi Control panel (connected to one of the two RJ48 sockets B, see appendix A). Operates only if the switch on the MultiPlus
is set to "on".
Only one remote control can be connected, i.e. either a switch or a remote control panel.
4.4.5. Programmable relays
The relays can be programmed for all kinds of applications, for example as a starter relay for a generating set.
4.4.6 Programmable analog/digital input/output ports
These ports can be used for several purposes. One application is communication with the BMS of a lithium-ion battery.
4.4.7 Auxiliary AC output (AC-out-2)
Besides the usual uninterruptable output, a second output (AC-out-2) is available that disconnects its load in the event of battery
operation. Example: an electric boiler or air conditioner that is allowed to operate only if the genset is running or shore power is
available.
In case of battery operation, AC-out-2 is switched off immediately. After the AC supply has become available, AC-out-2 is reconnected
with a delay of 2 minutes, this to allow a genset to stabilise prior to connecting a heavy load.
4.4.8 Parallel Connection
The MultiPlus can be connected in parallel with several identical devices. To this end, a connection is established between the devices
by means of standard RJ45 UTP cables. The system (one or more MultiPlus units plus optional control panel) will require subsequent
configuration (see Section 5).
In the event of connecting MultiPlus units in parallel, the following requirements must be met:
- A maximum of six units connected in parallel (per phase).
- Only identical devices may be connected in parallel.
- The DC connection cables to the devices must be of equal length and cross-section.
- The AC input cables to each unit as well as the AC output cables to each unit must also be of equal length and cross-section (length to
AC input may be different from length to AC output).
Additionally the AC input and output cables to each unit should have a minimum resistance of 4 milliohm (in oder to prevent excessive
AC current unbalance between parallel units due to differeces of terminal and relay contact resistance).
As a result the minimum length of the AC input and output cables is as follows:
Cable cross section 6 mm² (9 AWG): min. length 0,7 meter
Cable cross section 10 mm² (7 AWG): min. length 1,2 meter
- If a positive and a negative DC distribution point is used, the cross-section of the connection between the batteries and the DC
distribution point must at least equal the sum of the required cross-sections of the connections between the distribution point and the
MultiPlus units.
- Place the MultiPlus units close to each other, but allow at least 10 cm for ventilation purposes under, above and beside the units.
- UTP cables must be connected directly from one unit to the other (and to the remote panel). Connection/splitter boxes are not
permitted.
- A battery-temperature sensor need only be connected to one unit in the system. If the temperature of several batteries is to be
measured, you can also connect the sensors of other MultiPlus units in the system (with a maximum of one sensor per MultiPlus).
Temperature compensation during battery charging responds to the sensor indicating the highest temperature.
- Voltage sensing must be connected to the master (see Section 5.5.1.4).
- Only one remote control means (panel or switch) can be connected to the system.
4.4.9 Three-phase operation
The MultiPlus can also be used in 3-phase wye (Y) configuration. To this end, a connection between the devices is made by means of
standard RJ45 UTP cables (the same as for parallel operation). The system (MultPlus units plus an optional control panel) will require
subsequently configuration (see Section 5).
Pre-requisites: see Section 4.4.8.
Note: the MultiPlus is not suitable for 3-phase delta (Δ) configuration.
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