4. Installation
4.1. Location of the inverter
To ensure a trouble free operation of the inverter, it must be used in locations that meet the following requirements: a) Avoid any contact with water. Do not expose the inverter to rain or moisture. b) Do not place the unit in direct sunlight. Ambient air temperature should be between -20°C and 40°C (humidity < 95% non-condensing). c) Do not obstruct the airflow around the inverter. Leave at least 30 centimeters clearance above and below the inverter, and preferably installed upright and vertical When the unit is running too hot, it will shut down. When it has reached a safe temperature level the unit will automatically restart again. | |
This product contains potentially dangerous voltages. It should only be installed under the supervision of a suitable qualified installer with the appropriate training, and subject to local requirements. Please contact Victron Energy for further information or necessary training. | |
Excessively high ambient temperature will result in the following: · Reduced service life. · Reduced charging current. · Reduced peak capacity, or shutdown of the inverter. Never position the appliance directly above lead-acid batteries. The unit is suitable for wall mounting. For mounting purposes, a hook and two holes are provided at the back of the casing. The device must be fitted vertically for optimal cooling. | |
For safety purposes, this product should be installed in a heat-resistant environment. You should prevent the presence of e.g. chemicals, synthetic components, curtains or other textiles, etc., in the immediate vicinity. |
Try and keep the distance between the product and the battery to a minimum in order to minimise cable voltage losses
4.2. Battery and battery lead requirements
In order to utilize the full capacity of the product, batteries with sufficient capacity and battery cables with sufficient cross section should be used. The use of undersized batteries or battery cables will lead to:
Reduction in system efficiency.
Unwanted system alarms or shutdowns.
Permanent damage to system.
See table for MINIMUM battery and cable requirements.
Model | 450/100 | |
---|---|---|
Battery capacity Lead-acid | 200 Ah | |
Battery capacity Lithium | 50 Ah | |
Recommended DC fuse | 125 A - 150 A | |
Minimum cross section (mm2) per + and - connection terminal | 0 - 2 m | 35 mm 2 |
2 - 5 m | 70 mm 2 |
Warning
Consult battery manufacture recommendations to ensure the batteries can take the total charge current of the system. Decision on battery sizing should be made in consultation with your system designer.
Use a torque wrench with insulated box spanner in order to avoid shorting the battery. Maximum torque: 14 Nm Avoid shorting the battery cables. |
Undo the two screws at the bottom of the enclosure and remove the service panel.
Connect the battery cables.
Tighten the nuts well for minimal contact resistance.
4.3. Solar array configuration
The Multi RS Solar Dual tracker model must keep the individual tracker inputs isolated from each other. That means one solar PV array per input, do not attempt to connect the same array to multiple tracker inputs.
Warning
The maximum rated voltage of the solar charger is 450 V. A PV overvoltage event will damage the solar charger. This damage is not covered by warranty.
In case the PV array is located in colder climates the PV array can output more than its rated Voc. Use the MPPT sizing calculator on the solar charger product page to calculate this variable. As a rule of thumb, keep an additional 10% safety margin.
The maximum operational input current for each tracker is 13 A.
MPPT PV inputs are protected against reverse polarity, to a maximum short circuit current of 16 A for each tracker.
Warning
BEWARE that the product warranty will be void if a PV array with a short circuit current larger than 16 A array is connected in reverse polarity.
Caution
The Multi RS Solar Dual tracker model must keep the individual tracker inputs isolated from each other. That means one solar PV array per input, do not attempt to connect the same array to multiple tracker inputs.
When the MPPT switches to float stage it reduces battery charge current by increasing the PV Power Point voltage.
The maximum open circuit voltage of the PV array must be less than 8 times the minimum battery voltage when at float.
For example, where a battery has a float voltage of 54.0 volts, the maximum open circuit voltage of the connected array cannot exceed 432 volts.
Where the array voltage exceeds this parameter the system will give a "Over-charge Protection" error and shut down.
To correct this, either increase the battery float voltage, or reduce PV voltage by removing PV panels from the string to bring the voltage back within specification.
4.3.1. Multi RS Solar example PV configuration
Notice
This is an example of an array configuration. The decision on the specific array configuration, sizing and design for your system should be made in consultation with your system designer.
Panel Type | Voc | Vmpp | Isc | Impp | # of panels | Max String Voltages | Power total |
---|---|---|---|---|---|---|---|
Victron 260W (60 cell) | 36.75 V | 30 V | 9.30 A | 8.66 A | #1 - 8 #2 - 8 | 304 V | 4160 W |
4.4. MPPT grounding, detection of PV array insulation faults & Earth fault alarm notification
The RS will test for sufficient resistive isolation between PV+ and GND, and PV- and GND.
In the event of a resistance below the threshold (indicating an earth fault), the unit will stop charging and display the error.
If an audible alarm and/or email notification of this fault is required, then you must also connect a GX device (such as the Cerbo GX). Email notifications require an internet connection to the GX device and a VRM account to be configured.
The positive and negative conductors of the PV array must be isolated from ground.
Ground the frame of the PV array to local requirements. The ground lug on the chassis should be connected to the common earth.
The conductor from the ground lug on the chassis of the unit to earth should have at least the cross-section of the conductors used for the PV array.
When a PV resistance isolation fault is indicated, do not touch any metal parts and immediately contact a suitably qualified technician to inspect the system for faults.
The battery terminals are galvanically isolated from the PV array. This ensures that PV array voltages cannot leak to the battery side of the system in a fault condition.
4.5. Cable connection sequence
First: Confirm correct battery polarity, connect the battery.
Second: if required, connect the remote on-off, and programmable relay, and communications cables
Third: Confirm correct PV polarity, and then connect the solar array (if incorrectly connected with reverse polarity, the PV voltage will drop, the controller will heat up but will not charge the the battery).
4.6. Battery connection procedure
Proceed as follows to connect the battery cables:
Warning
Use a torque wrench with insulated box spanner in order to avoid shorting the battery. Avoid shorting the battery cables.
Warning
Specific care and attention must be taken when making the battery connections. Correct polarity must be confirmed with a multimeter before connection. Connecting a battery with incorrect polarity will destroy the device and is not covered by warranty.
Undo the two screws at the bottom of the enclosure and remove the service panel.
Connect the battery cables. First the - cable then the +. Be aware that there may be a spark when making the battery connections.
Tighten the nuts to the prescribed torques for minimal contact resistance.
4.7. Connection of the AC cabling
Warning
This 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 inside of the product must be provided with an uninterruptible grounding point for safety purposes. see Appendix A.
In a fixed installation, an uninterruptible grounding can be secured by means of the grounding wire of the AC input. Otherwise the casing must be grounded.
This product 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 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.
Do not invert neutral and phase when connecting the AC.
The inverter does NOT provide full galvanic isolation between the PV DC input and AC output. Therefor it is possible that DC voltage and current from the DC PV connections could be detected on the AC side.
Full galvanic isolation is provided between PV DC, and Battery DC.
AC-out-1 The AC output cable can be connected directly to the terminal block 'AC-out'. From left to right: "N" (neutral) - "PE" (earth) - "L" (phase). With its PowerAssist feature the Multi can add up to 6kVA (that is 6000 / 230 = 26A) to the output during periods of peak power requirement. The Multi RS can provide throughput of up to 50 A to the loads. The AC input relays are limited to 50 A (Multi RS - 2 tracker), and the inverter can contribute up to 25 A continuous at best conditions (when it gets hotter this figure will be reduced). . Torque: 1.2 Nm
Warning
The AC output terminals must be protected by a fuse or circuit breaker rated at 50 A or less, and cable cross-section must be sized accordingly. An earth leakage circuit breaker may additionally be required for local compliance.
AC-out-2 A second output is available that disconnects its load in the event of battery-only operation. On these terminals, equipment is connected that may only operate if AC voltage is available on AC-in-1, e.g. an electric boiler or an air conditioner. The load on AC-out-2 is disconnected immediately when the inverter/charger switches to battery operation. After AC power becomes available on AC-in-1, the load on AC-out-2 will also be reconnected immediately. Torque: 1.2 Nm.
AC-in The AC input cable can be connected to the terminal block 'AC–in'. From left to right: "N" (neutral) - "PE" (earth) - "L" (phase active) The AC input must be protected by a fuse or magnetic circuit breaker rated at 50 A 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. Torque: 1.2 Nm.
4.8. VE.Direct
This can be used to connect a PC/laptop to configure the inverter with a VE.Direct to USB accessory. Can also be used to connect a Victron GlobalLink 520 to allow for remote data monitoring.
Note the VE.Direct port on the Multi RS Solar cannot be used to connect to a GX device, and the VE.Can connection must be used instead.
4.9. VE.Can
Used to connect to a GX Device, and/or daily-chain communications to other VE.Can compatible products such as the VE.Can MPPT range.
4.10. Bluetooth
Used to connect to the device via VictronConnect for configuration.
Note that this Bluetooth interface is not compatible with VE.Smart Networking (i.e Smart Battery Sense).
4.11. User I/O
4.11.1. Remote on/off connector
The remote on/off connector has two terminals, the “Remote L” and the “Remote H” terminal.
The Multi RS Solar ships with the remote on/off connector terminals connected to each other via a wire link.
Note that for the remote connector to be operational, the main on/off switch on the Multi RS Solar needs to be switched to “on”
The remote on/off connector has two different operational modes:
On/off mode (default):
The default function of the remote on/off connector is to remotely switch the unit on or off.
The unit will switch on if “Remote L” and the “Remote H” are connected to each other (via a remote switch, relay or the wire link).
The unit will switch off if “Remote L” and the “Remote H” are not connected to each other and are free floating.
The unit will switch on if “Remote H” is connected to battery positive (Vcc).
The unit will switch on if “Remote L” is connected to battery negative (GND).
2-wire BMS mode:
This feature can be enabled via VictronConnect. Go to “battery settings” and then to “Remote mode”. (see attached image)
Set the remote mode from “on/off” to “2-wire BMS”.
In this mode, the “load”, “load disconnect” or “allowed to discharge” signal and the “charger”, “charger disconnect” or “allowed to charge” signals from a Victron lithium battery BMS are used to control the unit. They respectively turn the inverter off in case discharge is not allowed, and turn the solar charger off if charging is not allowed by the battery.
Connect the BMS “load”, “load disconnect” or “allowed to discharge” terminal to the Inverter RS Smart “Remote H” terminal.
Connect the BMS “charger”, “charge disconnect” or “allowed to charge” to the unit Inverter RS Smart “Remote L” terminal.
4.11.2. Programmable relay
Programmable relay which can be set for general alarm, DC under voltage or genset start/stop function. DC rating: 4A up to 35VDC and 1A up to 70VDC
4.11.3. Voltage sense
For compensating possible cable losses during charging, two sense wires can be connected directly to the battery or to the positive and negative distribution points. Use wire with a cross-section of 0,75mm².
During battery charging, the charger will compensate the voltage drop over the DC cables up to a maximum of 1 Volt (i.e. 1V over the positive connection and 1V over the negative connection). If the voltage drop threatens to become larger than 1V, the charging current is limited in such a way that the voltage drop remains limited to 1V.
4.11.4. Temperature sensor
For temperature-compensated charging, the temperature sensor (supplied with the unit) can be connected. The sensor is isolated and must be fitted to the negative terminal of the battery. The temperature sensor can also be used for low temperature cut-off when charging lithium batteries (configured in VictronConnect).
4.11.5. Programmable analog/digital input ports
The product is equipped with 2 analog/digital input ports, they are labelled AUX_IN1+ and AUX_IN2+ on the removable User I/O terminal block.
The digital inputs are 0-5v, and when a input is pulled to 0v it is registered as 'closed'
These ports can be configured in VictronConnect.
Unused: the aux input has no function.
Safety switch: the device is on when the aux input is active.
AC IN connect: only connect to AC input when AUX input is active. An example of when this might be useful is to disable AC input grid charging during an expensive time of use tariff period.
You can assign different functions to each aux input. In case the same function is assigned to both aux inputs then they will be treated as an AND function, so both will need to active for the device to recognise the input.
4.11.6. User I/O terminal diagram
4.11.7. User I/O functions
Number | Connection | Description |
---|---|---|
1 | Relay_NO | Programmable relay Normally Open connection |
2 | AUX_IN - | Common negative for programmable auxiliary inputs |
3 | AUX_IN1+ | Programmable auxiliary input 1 positive connection |
4 | AUX_IN2+ | Programmable auxiliary input 2 positive connection |
5 | REMOTE_L | Remote on/off connector Low |
6 | REMOTE_H | Remote on/off connector High |
7 | RELAY_NC | Programmable relay Normally Closed connection |
8 | RELAY_COM | Programmable relay common negative |
9 | TSENSE - | Temperature Sensor negative |
10 | TSENSE + | Temperature Sensor positive |
11 | VSENSE - | Voltage Sensor negative |
12 | VSENSE + | Voltage Sensor positive |
4.12. Programming with VictronConnect
This guide will help you with the specific elements of VictronConnect that relate to the MPPT Solar Charge Controller.
More general information about the VictonConnect App - how to install it; how to pair it with your device; and how to update firmware, for example - can be found by referring to the overall VictronConnect manual. A list of all VictronConnect compatible devices can be viewed here.
Note: These instructions can apply to different products and configurations, where battery voltage is referred to in these instructions, a 12V battery is used as a reference point. Please multiply the given values by 4 to arrive at settings for an installation configured for the 48V battery system.
4.12.1. Settings
The settings page is accessed by clicking on the Cog icon at the top right of the Home page. The settings page provides access to view or change the settings of the Battery; Load; Streetlight; and Port functions. From this page you can also view Product information such as the Firmware versions installed on the MPPT Solar Charger.
4.12.2. Battery settings
Battery voltage
The RS is fixed to 48V, and is only available for 48V systems.
Max charge current
Allows the user to set a lower maximum charge current.
Charger enabled
Toggling this setting turns the Solar Charger off. The batteries will not be charged. This setting is intended only for use when carrying-out work on the installation.
Charger settings - Battery preset
Battery preset allows you to select the battery type; accept factory defaults; or enter your own preset values to be used for the battery charge algorithm. The Absorption voltage, Absorption time, Float voltage, Equalisation voltage and Temperature compensation settings are all configured to a preset value - but can be user-defined.
User-defined presets will be stored in the preset library - in this way installers will not have to define all the values each time they are configuring a new installation.
By selecting Edit Presets, or on the Settings screen (with expert mode on or not), custom parameters can be set as follows:
Absorption voltage
Set the absorption voltage.
Adaptive absorption time
Select with adaptive absorption time or fixed absorption time will be used. Both are better explained below:
Fixed absorption time: The same length of absorption is applied every day (when there is enough solar power) by using the maximum absorption time setting. Be aware that this option can result in overcharging your batteries, especially for lead batteries and system with shallow daily discharges. See your battery manufacturer for recommended settings. Note: make sure to disable the tail current setting to make the same absorption time every day. The tail current could end absorption time sooner if the battery current is below the threshold. See more information on the tail current setting section below.
Adaptive absorption time: The charge algorithm can use an adaptive absorption time: it automatically adapts to the state of charge in the morning. The maximum duration of the absorption period for the day is determined by the battery voltage as measured just before the solar charger begins operation each morning (12 V battery values used - Multiply Battery voltage by 4 for 48V ):
Battery voltage Vb (@start-up) | Multiplier | Maximum absorption times |
---|---|---|
Vb < 11.9 V | x 1 | 06:00 hours |
> 11.9 V Vb < 12.2 V | x 2/3 | 04:00 hours |
> 12.2 V Vb < 12.6 V | x 1/3 | 02:00 hours |
Vb > 12.6 V | x 2/6 | 01:00 hours |
The multiplier is applied to the maximum absorption time setting and this results in the maximum duration of the absorption period used by the charger. The maximum absorption times shown in the last column of the table are based on the default maximum absorption time setting of 6 hours.
Maximum absorption time (hh:mm)
Set the absorption time limit. Only available when using a custom charge profile.
Enter the time value in the notation hh:mm, where hours are between 0 and 12; and minutes are between 0 and 59.
Float voltage
Set the float voltage.
Re-bulk voltage offset
Set the voltage offset that will be used over the float voltage setting that will determine the threshold that the charge cycle will restart.
E.g.: For a Re-bulk voltage offset off 0.1V and a float voltage setting of 13.8 V, the voltage threshold that will be use to restart the charge cycle will be 13.7 V. In other words, if the battery voltage drops below 13.7 V for one minute, the charge cycle will restart.
Equalization voltage
Set the equalization voltage.
Equalization current percentage
Set the percentage of the Max charge current setting that will be used when equalisation is performed.
Automatic Equalization
Set-up the frequency of the auto equalize function. Available options are between 1 and 250 days:
1 = daily
2 = every other day
...
250 = every 250 days
Equalization is typically used to balance the cells in a lead battery, and also to prevent stratification of the electrolyte in flooded batteries. Whether (automatic) equalization is necessary, or not, depends on the type of batteries, and their usage. Consult your battery supplier for guidelines.
When the Automatic equalization cycle has initiated, the charger applies an equalization voltage to the battery as long as the current level stays below the equalization current percentage setting of the bulk current.
Duration of the Automatic equalization cycle
In the case of all VRLA batteries and some flooded batteries (algorithm number 0, 1, 2 and 3) automatic equalization ends when the voltage limit (maxV) has been reached, or after a period equal to (absorption time/8) - whichever comes first.
For all tubular plate batteries (algorithm numbers 4, 5 & 6); and also for the user-defined battery type, automatic equalization will end after a period equal to (absorption time/2).
For the Lithium battery type (algorithm number 7), equalization is not available.
When an automatic equalization cycle is not completed in one day, it will not resume the next day. The next equalization session will take place according to the interval set in the 'Auto Equalization' option.
The default battery type is a VRLA battery and any user-defined battery will behave as a tubular plate battery with regard to equalization.
Equalisation stop mode
Set how the equalisation will end. There are two possibilities, first is if the battery voltage reaches the equalisation voltage and the second is on fixed time, where the maximum equalisation duration is used.
Maximum equalisation duration
Set the maximum time that the equalisation phase will last.
Tail current
Set the current threshold that will be used to finish absorption phase before the maximum absorption time expires. When the battery current gets below the tail current for one minute, the absorption phase will end. This setting can be disabled by setting it to zero.
Temperature compensation
Many types of battery require a lower charge voltage in warm operating conditions, and a higher charge voltage in cold operating conditions.
The configured coefficient is in mV per degree Celsius for the whole battery bank, not per cell. The base temperature for the compensation is 25°C (77°F), as shown in the chart below.
With a temperature sensor installed to the User I/O connection block; the actual battery temperature will be used for compensation; throughout the day.
Low temperature cut-off
This setting can be used to disable charging at low temperatures as required by Lithium batteries.
For Lithium Iron Phosphate batteries this setting is preset at 5 degrees Celsius, for the other battery types it is disabled. When creating a user defined battery the cut-off temperature level can be adjusted manually.
Manual Equalization - Start now
Selecting 'Start now' on 'Manual equalisation' allows manual initiation of an Equalization cycle. To allow the charger to equalize the battery properly use the manual equalize option only during absorption and float periods, and when there is sufficient sunlight. Current and voltage limits are identical to the automatic equalize function. The duration of the equalisation cycle is limited to a maximum of 1 hour when triggered manually. Manual equalization can be stopped at any time by selecting 'Stop Equalize'.
4.12.3. Generator programming
The Multi RS Solar has a tolerance for irregularities on the AC input like fast frequency changes or voltage changes to improve reliability when connecting to generators.
Using a generator with the Multi RS Solar requires firmware version v1.11 or later.
If using a generator; it is recommended to adjust these settings;
VictronConnect -> Settings -> General -> Enable 'Moderate generator load changes'.
VictronConnect -> Settings -> Grid -> Disable the 'UPS function'.
The 'moderate generator load changes' setting enables the inverter/charger to absorb sudden load changes and slowly transfer them to the generator. This reduces speed and voltage variations in the generator.
The 'UPS function' restricts the acceptance of an AC input to a very precise sine wave so that in the event of an interruption in the AC supply it is possible to maintain an apparent continuity of supply to the loads. This is incompatible with most generators and should be disabled when using a generator to improve reliable acceptance of the AC supply.
Limitations
The Multi RS Solar includes limited relay control options such as open/close on a programmable low battery voltage. For more advanced generator control programming functionality, please use a GX device (such as the Cerbo GX).
See Limitations chapter for additional charging power limitations.
4.12.4. UPS behaviour
The UPS feature enables a faster transfer to inverter mode when the AC input supply is interrupted.
This function is enabled by default, and should be disabled when using a generator (or grid with irregular sinewave).
The setting in located in VictronConnect -> Settings -> Grid -> UPS function.
The 'UPS function' limits the acceptance of an AC input to a very precise sine wave so that in the event of an interruption in the AC supply it is possible to maintain an apparent uninterrupted continuous power supply to the loads.
The typical response time at a sudden drop of the grid voltage is 6 ms. If the AC input drop starts around the zero crossing of the sine the response time is about 8ms. This is including the response time of the relay.
In case the inverter is able to supply sufficient power into the AC input the response time for the ac in-relay to open might take longer. However the load is still supplied continuously with at least >160Vrms. The AC input relay is always opened within 200ms.
Victron Energy does not recommend the use of this product in life support applications where failure or malfunction of Victron Energy's product can be reasonably expected to cause the failure of the life support device or to significantly affect its safety or effectiveness.
4.12.5. AC Input Control
The AC Input Control can be set up in numerous ways, for example, the Multi will disconnect from the grid when the batteries are full enough and/or the AC load is not too big. The Multi will disconnect from the grid most of the time. It will only let the grid in when the batteries are empty or when you are running a big AC load. You now can use the grid like you would use a backup generator.
The mechanism behind the AC Input Control is the opening or closing the Multi’s internal AC input relay.
This feature in not enabled by default.
The normal function of this relay is to open as soon as the grid or generator is not there. For example, during a blackout or when a generator is off. This is a safety action. The relay prevents energy feeding into the grid during a blackout or when the generator is off.
This relay can also be setup to purposefully ignore the grid. It will still perform its normal safety action but it can open and disconnect from the grid under more situations. It can ignore the grid when the batteries are still full enough. Now DC solar power can be prioritized and the grid will be used like a backup generator
When can the grid be controlled?
The AC input relay can be programmed to selectively ignore the grid, while looking at two parameters: It can look at battery voltage and/or at AC load parameters.
The grid is ignored when the batteries are full enough. The grid is let in when the batteries are empty:
This setting can be used to charge the batteries from the grid should the batteries get too empty. This can occur, for example, at night or during a long period of bad weather.
In this scenario the Multi will look at the battery voltage. It will let the grid in when the battery voltage is too low, for a certain amount of time. It will ignore the grid as soon as the battery voltage has increased above a certain level, for a certain amount of time.
The multi can also disconnect the grid on battery state of charge.
The grid is ignored when the AC loads are low. The grid is let in when the AC loads are high:
This setting can be used to allow grid in when the AC load is higher than the Multi rating. This will prevent the Multi going into overload. This setting can also be used for large loads that you do not want to run from the battery.
In this scenario the Multi will look at the AC load. As soon as it sees that the load is above a certain level, for a certain amount of time, the Multi will let the grid in. The multi will stop letting the grid in as soon as it sees that the AC load has dropped below a certain level, for a certain amount of time.
Conditional AC input activation
Enables the use of AC Input Control to modify the operation of the feedback relay.
Load Conditions
This setting can be used to allow grid in when the AC load is higher than the Multi rating. This will prevent the Multi going into overload. This setting can also be used for large loads that you do not want to run from the battery.
In this example the grid will not be ignored when the load exceeds 4000 Watts, with no delay.
Do not ignore AC input means that the grid is accepted because the AC input relay is closed. The grid will be ignored when the load drops below 2000 W.
Ignore AC means that the grid is ignored because the AC input relay is open.
Depending on your load, if the AC input relay is opening and closing frequently, add a time delay before activation and deactivation.
AC input activation based on load
Activate when load is higher than W
Delay before activation T
Deactive when load is lower than W
Delay before deactivation T
Battery Conditions
This setting can be used to charge the batteries from the grid should the batteries get too empty. This can occur, for example, at night or during a long period of bad weather.
In this example, the grid is not ignored when the battery voltage is less than 47 Volt. Do not ignore AC input means that the grid is accepted because the AC input relay is closed.
The grid will be ignored again when the battery voltage exceeds 52 Volts for more than 5 minutes.
Ignore AC means that the grid is ignored because the AC input relay is open. Apart from “battery voltage”, there are two other options to choose from: “bulk finished” or “absorption finished”.
Choosing “absorption finished” is a good way to ensure the batteries are getting a full charge every now and then. But it can lead to a higher electricity bill. The absorption charge stage of a lead-acid battery is much less efficient than the bulk stage.
This could be a reason to choose the “bulk finished” option. At the end of the bulk charge stage a lead-acid battery is about 85% full.
For more information about bulk and absorption please see the Victron Energy book “Energy Unlimited”, page 25. Follow this link: https://www.victronenergy.com.au/orderbook
It is also possible to let grid in when the batteries fall below a certain state of charge.
Important
In a system that contains additional charge sources external to the Multi, or DC loads, the “state of charge” option should only be used if you also have a GX device in the system. And the GX device is connected to both the Multi and the external MPPT solar charger(s) and/or a BMV battery monitor. See this link for more information: https://www.victronenergy.com/media/pg/CCGX/en/configuration.html#UUID-3d1bea6f-30a0-7d84-8ba6-dab25033ba16
4.12.6. Inverter Modes
On / Off Menu
The On/Off menu in VictronConnect provides several modes of operation.
ON
This will turn the unit ON via the software toggle, this is the default mode of operation.
Using this mode requires that the physical hardware ON/OFF switch is set to ON.
Turning the physical hardware switch OFF will turn the unit off, and cannot be overridden by the software ON switch.
OFF
This will turn the unit OFF via the software control.
The physical hardware switch set to ON will be overridden by the software OFF setting.
The unit will turn OFF if the physical hardware switch is set to ON, but the software switch is set to OFF.
Inverter Only
Inverter only mode disconnects the AC input from the grid by opening the AC input relay.
The solar charger is still active in this mode.
Charger Only
Charger only mode turns off the Inverter providing AC voltage to the AC output.
The charger will charge the batteries from the AC input in this mode.
The solar charger is still active in this mode.
Pass Through
This mode closes the AC input relay and passes through AC voltage from the AC input to the AC output while the inverter/charger remains off.
The solar charger remains active.
4.12.7. ESS controls
The factory default operation when an AC input is connected to a Multi RS is that the charger will begin charging the batteries up to the maximum AC input current and charge current limits. We call this factory default mode "Keep batteries charged".
In some cases the user may want to only use the AC input to charge the battery when necessary, and instead allow the batteries to discharge to provide for the loads and recharge from solar.
To enable this flexibility there are several possible configuration options.
It is possible to use the 'Conditional AC input connection', this will physically disconnect the AC input relay, disconnecting the AC input supply unless the programmed parameters are met.
When the parameters are met, then the AC input relay will close, connecting the AC input and the Multi RS will charge the battery from the AC input.
If it is preferred to keep the AC input relay closed, and the AC input connected, but not use it to continuously charge the battery, there is another option called ESS Optimised mode.
Keep Batteries Charged
This is the factory default mode selected. This setting will keep the batteries fully charged. Utility grid failure is then the only time battery power is used - as a backup. Once the grid is restored, the batteries will be recharged either from the grid or from solar panels - when available.
Even you choose to normally run in an optimised mode, it may be useful to use this mode if you're expecting a storm that might disrupt the AC supply and you want to make sure the batteries are fully charged before the power goes out.
Optimised
This mode will keep the AC input relay closed, but will only use the AC input supply to maintain the battery at the 'Minimum discharge SOC' setting.
When there is more PV power than is required to run loads, the excess PV energy is stored in the battery. That stored energy is then used to power the loads at times when there is a shortage of PV power.
This mode also maintains PowerAssist. This means if the load is larger than the inverter is able to provide it will use power from the AC input to support it.
The percentage of battery capacity used for self-consumption is configurable. When utility grid failure is extremely rare it could be set to 100%. In locations where grid failure is common - or even a daily occurrence - you might choose to use just 20% of battery capacity and save 80% of the storage capacity to provide for the next grid failure.
Batterylife
Batterylife refers to an algorithm that will automatically increase the minimum SOC if the battery is not getting regularly recharged.
Once the battery is getting fully charged again, the BatteryLife algorithm will reduce the minimum SOC back down again until it reaches the mimimum SOC set by the user in the VictronConnect ESS menu.
Sustain
This mode is not user selectable.
When the battery voltage hits the shutdown level or the BMS indicates that the battery is empty, the unit will change to 'SUSTAIN' mode and allow a trickle charge mode (5A) from the AC input.
Limitations
Please note that the ESS implementation for the VE.Can Multi RS is managed differently to that for the VE.Bus products. No assistant is required to be installed, ESS settings are available out of the box.
It is not yet possible to adjust the available ESS settings via the ESS menu of the GX. The ESS menu of the GX will display 'No ESS Assistant found'.
It is also not possible to change ESS settings via the controls menu of VRM.
Multi RS ESS settings can only be changed via VictronConnect, and the ESS menu in the settings there.
This can be done locally via Bluetooth or VE.Direct to USB, and also remotely if the system is connected via a GX device to VRM, with Remote VictronConnect.
Grid Code compliance is not yet available for the Multi RS. So export is not allowed by software.
4.13. Connecting to AC PV inverters
The Multi includes a built in AC PV inverter detection system. When there is a feedback of AC PV (a surplus) from the AC-out connection port, the Multi will automatically enable an AC output frequency adjustment.
While no further configuration is required, it is important that the AC PV inverter is configured correctly to respond to the frequency adjustment by reducing its output.
Note the 1:1 rule of AC PV inverter size to Multi size, and minimum battery sizing applies. More information about these limitations are available in the AC Coupling manual, and this document is required reading if using an AC PV inverter.
The frequency adjustment range is not configurable, and includes a built in safety margin. Once the absorption voltage is reached, the frequency will increase. So it is still essential to include a DC PV component in the system for complete battery charging (i.e. float stage).
It may be possible to adjust the power output response to various frequencies on your AC PV inverter.
The default configuration has been tested and works reliably with the Fronius MG50/60 grid code configuration.
4.14. Large systems - 3 phase
Warning
3 phase systems are complex. We do not support or recommend that untrained and/or inexperienced installers work on these size systems.
If you are new to Victron, please start with small system designs, so that you become familiar with the necessary training, equipment and software required.
It is also recommended to hire an installer that has experience with these more complex Victron systems, for both the design and the commissioning.
Victron is able to provide specific training for these systems to distributors via their regional sales manager.
Note
VE.Can 3 phase networking differs from VE.Bus. Please read the documentation in full, even if you have experience with large VE.Bus systems.
Mixing different models of Inverter RS (ie. the model with Solar and without Solar) is possible. However mixing Inverter RS with Multi RS is not currently supported.
DC and AC wiring
Each unit needs to be fused individually on the AC and DC side. Make sure to use the same type of fuse on each unit.
The complete system must be wired to a single battery bank. We do not currently support multiple different battery banks for one connected 3 phase system.
Communication wiring
All units must be daisy chained with a VE.Can cable (RJ45 cat5, cat5e, or cat6). The sequence for this is not important.
Terminators must be used at either ends of the VE.Can network.
The temperature sensor can be wired to any unit in the system. For a large battery bank it is possible to wire multiple temperature sensors. The system will use the one with the highest temperature to determine the temperature compensation.
Programming
All settings need to be set manually by changing the settings in each device, one by one. For now synchronising settings to all devices is not supported by VictronConnect.
There is a partial exception to this - changing the AC output voltage will temporarily be pushed to other synchronised devices (to prevent undesired power flow imbalance via the AC output). However this is not a permanent settings change and still needs to be manually set on all devices if you wish to change the AC output voltage.
Charger settings (voltage and current limits) are overridden if DVCC is configured and if a BMS-Can BMS is active in the system.
System Monitoring
It is strongly recommended that a GX Family Product is used in conjunction with these larger systems. They provide highly valuable information on the history and performance of the system.
System notifications are clearly presented and many additional functions are enabled. Data from VRM will greatly speed support if it is required.
4.15. 3 phase installation
The Multi RS Solar supports single phase, and three phase configurations. It does not currently support split phase.
The factory default is for stand alone, single unit operation.
If you wish to program for three phase operation, it requires at least 3 units.
The maximum supported system size is 3 units in total, with a single unit on each phase.
They must be connected to each other via VE.Can connections, with a VE.Can terminator (supplied) at the start and the end of the bus.
Once the units are connected to the battery and via VE.Can they will need to be configured.
Delta configurations not supported
For units in 3 phase configuration: Our products have been designed for a star (Y) type three phase configuration. In a star configuration all neutrals are connected, a so called: “distributed neutral”.
We do not support a delta (Δ) configuration. A delta configuration does not have a distributed neutral and will lead to certain inverter features not operating as expected.
4.16. 3 phase programming
In order to configure a 3 phase system the Multi RS Solar will need to be correctly installed, and running firmware version v1.13 or later.
Configuring a system for three phase or single phase is done in VictronConnect in the System menu.
Caution
AC output power will be disconnected for a few seconds when switching System configuration modes. Make sure the system is configured BEFORE connecting inverter AC output to the loads.
The factory default setting is Standalone (a single unit).
To set up a 3 phase system, connect to the first unit in VictronConnect, change the System setting to Three phase, and then select the correct phase for that unit (L1, or L2, or L3)
You will need to do this individually for each unit.
It is recommended to physically label the front of each unit, as well as give it a custom name in VictronConnect to match the physical label.
Prevent CAN network islanding toggle
This feature determines what the system does in case of a broken CAN connection between the RS units, and enables the 'Number of inverters in the system' setting below. Default is enabled.
If three Multi RSes are configured in three phase, each individual unit will only continue to work if it sees at least one other unit. This feature is only relevant in combination with the "Continue with missing phase" feature.
Number of inverters in the system
Enter the total number of RS units installed in the system. This should be set to 3 for a 3 phase Multi RS system.
In case a CAN connection is broken between two units the network is split into segments, this setting is used to determine the largest and shut down the smaller segment to prevent them from continuing on their own unsynchronised.
Note that setting the option "Continue with missing phase" to disabled overrules this behavior in such a way that it always ensures that all three phases must be powered at all times, so a broken CAN connection in a 3 phase setup will shut down all units.
Minimum number of inverters to start
Minimum number of inverters that must be present per phase when starting the system.
Set to 1 means that all 3 units in a 3 phase Multi RS system must be present to start.
Note
These System settings must be programmed individually, and set correctly on all connected inverters for synchronised operation.
Note on redundancy and continuous output during firmware updates
A three phase system can be firmware updated without losing power on the AC output.
Make sure that there is stable AC input available when starting the update and the unit currently being updated will switch to AC-passthru mode.
The AC synchronisation mechanism used for 3 phase has a 'protocol' version embedded.
Units can work together even with different firmware versions, as long as they are running the same protocol version.
This allows for continuous uninterrupted supply even when updating firmware, as the units will individually update one at a time, while others continue to synchronise and provide the stable AC output.
If Victron needs to change the 'protocol' version number, it will be clearly noted in the firmware change log. Always read this before updating.
In the event that there are multiple protocol versions running on the same VE.Can bus, all units will indicate error #71 until they are all updated to the same version.
Continue with Missing Phase
It is possible to configure the system so that if one unit is offline (for example due to it being physically switched off or a firmware update in case there is no grid connection to allow pass-thru), the other units can continue to operate and provide AC output power to their respective phases.
By default, the 'continue with missing phase' is disabled. Switching one unit off with the physical switch will make that unit switch off. If the unit is one of three units that are in three phase, then the others will also turn off as well.
If configured with 'Continue with missing phase' enabled, and minimum number of units is sufficient, then output to the other phases will continue even though its down to less phases than configured.
The 'Continue with missing phase' configuration option SHOULD NOT be enabled if there are specific three phase loads connected that require all three synchronised phases to operate (such as a three phase electric motor).
In that situation maintain the default 'disabled' setting for "Continue with missing phase".
Warning
Attempting to run a three phase load with only two phases operating could result in damage to your appliance.
Warning
If you have configured the system to continue to operate with a missing phase, and there is an issue with the VE.Can communications between the units (such as the wire being damaged), then the units will continue to operate, but will not be synchronising their output wave forms.
System Instance
Units with the same instance number work together on the AC side.
Changing the System instance setting allows multiple groups of Inverters to be on the same VE.Can bus, but not synchronised, and segmented into different AC outputs, without interference.
Continue with the same programming settings on the rest of the units.
Known Issues
The 'UPS function' is too sensitive in 3 phase operation compared to stand-alone operation. Disable the 'UPS function' in case the Multi disconnects frequently from the AC input.
Charge currents are not yet balanced across the 3-phases when the charger is in voltage-controlled mode.