multiplus_faq
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multiplus_faq [2017-06-27 04:49] – guystewart | multiplus_faq [2024-07-17 06:57] (current) – [4.1 PowerAssist] guy_stewart | ||
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- | What to do when a MultiPlus does not accept generator power | + | __What |
- | ---- | + | __ |
Power supply from a generator is typically more variable than a power supply from shore or the main grid. The MultiPlus is sensitive to this and will reject power that is outside of it's programmed settings causing the unit to not connect, synchronise or charge. | Power supply from a generator is typically more variable than a power supply from shore or the main grid. The MultiPlus is sensitive to this and will reject power that is outside of it's programmed settings causing the unit to not connect, synchronise or charge. | ||
- | **Selecting a Generator** | + | ==== Selecting a Generator |
- | Some generators are more suitable than others for use with inverter/ | + | |
+ | Some generators are more suitable than others for use with inverter/ | ||
For example; some things to look for when selecting a generator is a high quality alternator and AVR (auto voltage regulation). | For example; some things to look for when selecting a generator is a high quality alternator and AVR (auto voltage regulation). | ||
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AVR equipped generators will audibly struggle and eventually stall when overloaded, signalling there is an issue. They are also better able to cope with a brief high current load which would overload an inverter based generator. | AVR equipped generators will audibly struggle and eventually stall when overloaded, signalling there is an issue. They are also better able to cope with a brief high current load which would overload an inverter based generator. | ||
- | Inverter based generators have a characteristic where the motor continues to run even if the unit has electronically overloaded and no longer delivering power. It may appear that the generator is operating and the system is charging when it isn't. These units are also more easily overloaded by surge loads. | + | Inverter based generators have a characteristic where the motor continues to run even if the unit has electronically overloaded and no longer delivering power. It may appear that the generator is operating and the system is charging when it isn't. These units are also more easily overloaded by surge loads, as they are electronically limited rather than mechanically. |
+ | |||
+ | Make sure that the generator, inverter/ | ||
+ | Eg 230V / 50hz. Do not mix and match frequencies and voltages, or parts from different regions. | ||
+ | |||
+ | |||
+ | ==== Generator Sizing ==== | ||
+ | |||
+ | It is possible to overload generators with the power demanded by the Multi' | ||
+ | |||
+ | ^ Inverter Charger Size ^ Minimum Recommended Generator Size ^ 240V AC Input Current Limit ^ | ||
+ | | 800VA | 2 kVa | 5A | | ||
+ | | 1200VA | 2.5 kVa | 7A | | ||
+ | | 1600VA | 3 kVa | 10A | | ||
+ | | 3000VA | 5 kVa | 16A | | ||
+ | | 5000VA | 8 kVa | 25A | | ||
+ | |||
+ | If your generator is smaller than the recommended size for your inverter/ | ||
+ | |||
+ | If you do want an inverter based generator (eg for noise reasons under lower loading), get one that is at least 30% larger than required than an equivalent AVR based model to help prevent nuisance overloads. | ||
+ | |||
+ | It is also important to look at the DUTY CYCLE rating of the generator. Some generators are marketed for their peak output, but may only be designed to sustain 50% of that peak load rating for longer periods of time. | ||
+ | |||
+ | Battery charging is a very heavy use case load for a generator, so make sure it is up to the job, and the installation has plenty of good airflow and ventilation when operating to allow for heat to dissipate. | ||
+ | Some generators are only designed to operate for several hours, before requiring time to rest and cool down. Make sure this limitation is part of your load profile and system design. | ||
+ | ==== Operation ==== | ||
- | **Operation** | ||
It is important to note that the inverter/ | It is important to note that the inverter/ | ||
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- | **Software | + | ==== Software |
The settings which you should attempt first are ' | The settings which you should attempt first are ' | ||
- | If the generator will still not synchronise or disconnects, | + | If the generator will still not synchronise or disconnects, |
Lastly, adjusting the settings for Voltage and Frequency windows. These are higher risk to your appliances, they should only be used cautiously when it is confirmed that the loads will tolerate the out of specification power supply. This should be done by a competent technician with the aid of a multimeter and only opened so far as to allow for safe functionality. | Lastly, adjusting the settings for Voltage and Frequency windows. These are higher risk to your appliances, they should only be used cautiously when it is confirmed that the loads will tolerate the out of specification power supply. This should be done by a competent technician with the aid of a multimeter and only opened so far as to allow for safe functionality. | ||
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Warning: changing these settings will allow to feed-through current that may be of insufficient quality for the electrical requirements of your equipment. | Warning: changing these settings will allow to feed-through current that may be of insufficient quality for the electrical requirements of your equipment. | ||
- | ====== 1. In the “Grid” tab of VE-Configure: ====== | + | For information on VEConfigure and how to get started, please see this [[https:// |
+ | |||
+ | ====== 1. In the “Grid” tab of VEConfigure: ====== | ||
| | ||
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**AC low disconnect: | **AC low disconnect: | ||
- | **AC Low connect:** minimum value: at this value or any higher value, the MultiPlus will reconnect after having disconnected (default = 187Vac). | + | On generators where the output voltage drops under load, setting |
+ | The reason this happens is that the Multi will synchronise and follow the generator voltage as it sags. | ||
+ | |||
+ | If the generator is disconnected under load (either due to low-voltage disconnection, | ||
+ | |||
+ | As overload is driven by current, not power, this can result in an overload. | ||
+ | |||
+ | By increasing this minimum voltage level, you tell the inverter/ | ||
+ | |||
+ | **AC Low connect:** minimum value: at this value or any higher value, the MultiPlus will reconnect after having disconnected (default = 187Vac). | ||
===== 1.4 Maximum voltage levels ===== | ===== 1.4 Maximum voltage levels ===== | ||
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+ | ===== 1.5 Loss of mains detection (LOM) (Only applicable to ESS systems) ===== | ||
- | ====== 2. In the “General” tab of VE-Configure: ====== | + | This part is only applicable on systems where a grid-code is selected (generally only ESS systems) on an off-grid system a grid code should not be used and in the selection box for grid code, ' |
+ | |||
+ | Loss of mains detection will push and pull at voltage and frequency to see if there is still a generating source. This process can cause issues with some generators, or high impedance connections to generators. | ||
+ | |||
+ | For large and stable Generators Type B LOM will work, and is safer. | ||
+ | However, if you are experiencing issues with voltage, frequency or power fluctuations, | ||
+ | |||
+ | **Disabling LOM** | ||
+ | |||
+ | Disabling the LOM on an input connected to the grid is only allowed when other external safety equipment is installed. | ||
+ | Disabling the LOM on an input connected to generator can be done, but then other methods / warning signs / physical lockout safety measures must be provided. Ensuring that any installer that will work on the generator, wiring or system, will make sure to also switch off or otherwise disconnect the Inverter/ | ||
+ | |||
+ | For Full information on Loss of Mains detection, please see [[ve.bus: | ||
+ | |||
+ | |||
+ | **Example configuration in VEConfigure** | ||
+ | |||
+ | * A generator that requires LOM to be disabled. | ||
+ | * Generator on AC in 1, and grid on AC in 2, as recommended. | ||
+ | |||
+ | {{:: | ||
+ | |||
+ | |||
+ | |||
+ | ====== 2. In the “General” tab of VEConfigure: ====== | ||
{{:: | {{:: | ||
- | ===== 2.1 Load impact limitation ===== | ||
- | **Dynamic current limiter** : (default = disabled) | + | ===== 2.1 Dynamic current limiter |
+ | |||
+ | (default = disabled) | ||
This feature is intended to reduce load impacts on low-power generators, such as portable inverter technology models. These generators may be unable to respond to sudden load impacts. | This feature is intended to reduce load impacts on low-power generators, such as portable inverter technology models. These generators may be unable to respond to sudden load impacts. | ||
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By activating the limiter, the **PowerAssist®** function of the MultiPlus will absorb the change in load and transfer it smoothly to the generator, giving it time to react. | By activating the limiter, the **PowerAssist®** function of the MultiPlus will absorb the change in load and transfer it smoothly to the generator, giving it time to react. | ||
- | ====== 3. In the " | + | ===== 2.2 AC Input Current Limit ===== |
+ | |||
+ | The charger on the Multiplus is very powerful. If you have an existing generator that is not able to supply the maximum charging current of the Multi, you will need to adjust the AC Input Current Limit in the General Tab of VEConfigure. | ||
+ | |||
+ | A reasonable starting point for the AC Current input limit is 80% of the generator capacity in Watts. For example: | ||
+ | |||
+ | a 5kVA generator typically provides about 4 kW | ||
+ | |||
+ | 80% of 4 kW is 3200 W | ||
+ | |||
+ | 3200 W / 230 V volts = 13.9 A | ||
+ | |||
+ | Set the AC Current Input Limit to 13 A | ||
+ | |||
+ | If you find the generator is still overloading, | ||
+ | |||
+ | There is another additional setting in the Charger Tab for DC current limiting. | ||
+ | |||
+ | The AC input current should be adjusted first, as it also takes into account the PowerAssist functionality. | ||
+ | |||
+ | The Multi is able to synchronise the generator waveform with it's own and provide power to the loads from the generator as well charging the battery. This means it still possible to overload the generator with a low 'DC Charger current limit' if the AC input limit is not also set correctly to the size of the generators output. | ||
+ | |||
+ | |||
+ | ====== 3. In the " | ||
{{: | {{: | ||
- | **Derating of the power factor** | + | ===== 3.1 Derating of the power factor |
Some generators have a waveform which makes it difficult to charge with the normal charge mechanism. Through activating the " | Some generators have a waveform which makes it difficult to charge with the normal charge mechanism. Through activating the " | ||
Disadvantage of using this option is that the input power factor, normally equal or close to 1, will be degraded. This function should be used only when the preceding ones are ineffective. | Disadvantage of using this option is that the input power factor, normally equal or close to 1, will be degraded. This function should be used only when the preceding ones are ineffective. | ||
+ | |||
+ | This leading or lagging power factor will have the effect of demanding more kVa from the generator for the same or less DC Watts delivered to the batteries. You may need to further reduce the DC Current Limit in the Charger tab of VEConfigure if the generator continues to overload after changing this setting. | ||
+ | |||
+ | Effectively, | ||
+ | |||
**Important note:** | **Important note:** | ||
- | A detailed description of all settings is available in the VE-Configure | + | A detailed description of all settings is available in the VEConfigure |
+ | |||
+ | ====== 4. In the “Inverter” tab of VEConfigure: | ||
+ | |||
+ | ===== 4.1 PowerAssist ===== | ||
+ | |||
+ | {{:: | ||
+ | |||
+ | The [[https:// | ||
+ | |||
+ | If you have a small generator and have trouble getting connected or staying connected, Disable PowerAssist to allow the device to reduce the AC input current limit. | ||
+ | |||
+ | There is an additional configurable parameter of PowerAssist called "Boost factor" | ||
+ | |||
+ | When the Multi is charging from the generator, and the current required exceeds the AC input current limit (due to a sudden additional load) then the Multi will switch to PowerAssist mode. | ||
+ | |||
+ | At that moment the precise current needed is unknown. The Multi uses the " | ||
+ | |||
+ | In some cases this multiple is either too high, or too low. This would most likely present as the generator unable to stay connected, or fluctuations to the frequency and voltage. | ||
+ | |||
+ | The fastest way to diagnose if setting may be interfering with your specific generator and load operation is to disable power assist entirely. If that resolves the issue, then try reducing the Assist current boost factor down until it works reliably and still getting the benefit of the feature without the interference. The optimal value for this will depend on the size of the inverter, the size of the generator, and the size of the load. | ||
+ | |||
+ | ====== 5. Generator control in 3 phase and parallel systems ====== | ||
+ | |||
+ | There is some specific and non-intuitive conditions when setting AC input current limits, and Charge Current limits for Large systems that involve more than one MultiPlus, and/or a GX device. | ||
+ | |||
+ | Those specific details are articulated here: | ||
+ | https:// | ||
+ | |||
+ | Described in the online training theory here: | ||
+ | @ 38 minutes and 43 seconds - https:// | ||
+ | |||
+ | Demonstrated in the 3 phase installation training here: | ||
+ | @ 25 minutes - https:// | ||
+ | |||
+ | ====== Still not connecting? ====== | ||
+ | |||
+ | If the unit is still not connecting, | ||
+ | |||
+ | Check the VE.Bus Monitor and AC Input Connection timer | ||
+ | |||
+ | {{:: | ||
+ | |||
+ | With Multi firmwares xxyy460 and up, VEConfig will indicate why the AC Input is rejected and will also show an indication of the remaining waiting time as a blue bar. | ||
+ | |||
+ | After the waiting time the unit will connect to AC input provided that there is no assistant which prevents the unit from connecting to grid and that the required relay test is performed. | ||
+ | |||
+ | Switch the Multi over to Charger only mode. | ||
+ | |||
+ | Try with a different generator. | ||
+ | |||
+ | As troubleshooting and correcting these faults have serious safety implications, | ||
+ | |||
+ | There can be issues with generators with Residual Current Devices (RCD' | ||
+ | |||
+ | Simplify the AC wiring, With everything safely shut down and tested for voltage, disconnect the AC-Output active, neutral and earth. Direct wire in the generator connections, | ||
+ | |||
+ | If there is still no connection, contact your dealer or distributor. Tell them the steps that you have taken already to attempt to get it to work and they can help from there. | ||
+ | |||
+ | |||
+ | ====== Further Reading ====== | ||
+ | |||
+ | There have been extensive articles and documentation written about generators and their interaction with Victron systems. This includes troubleshooting, | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | ===== Community Discussion on MultiPlus 2x120 and generator phase compatibility ===== | ||
+ | |||
+ | [[https:// | ||
+ | |||
+ | [[https:// | ||
+ |
multiplus_faq.1498531768.txt.gz · Last modified: 2017-06-27 04:49 by guystewart