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--- multiplus_faq [2019-12-01 23:50] – updated ve-configure to veconfigure guy_stewart
+++ multiplus_faq [2024-07-17 06:57] (current) – [4.1 PowerAssist] guy_stewart
@@ Line 10: / Line 10: @@
-Some generators are more suitable than others for use with inverter/chargers, please talk to your local Victron Dealer before purchasing a generator and they may be able to advise you on locally available units that have been tested and are known to be good.
+Some generators are more suitable than others for use with inverter/chargers, please talk to [[https://www.victronenergy.com/where-to-buy|your local Victron Dealer]] before purchasing a generator and they may be able to advise you on locally available units that have been tested and are known to be good. It is recommended to get a generator from a supplier that is local to you for issues and servicing.
 For example; some things to look for when selecting a generator is a high quality alternator and AVR (auto voltage regulation).
@@ Line 35: / Line 35: @@
 If your generator is smaller than the recommended size for your inverter/charger, you will definitely need to adjust the settings on the inverter/charger and reduce the AC input current limit, and/or a DC charge current limit to prevent overloading the generator.
+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 ====
@@ Line 45: / Line 52: @@
-==== Software Changes ====
+==== Software Settings ====
 The settings which you should attempt first are 'Disable UPS mode' and 'Enable Dynamic Current limiting'. These compromise features, but maintain the quality of the power supply.
-If the generator will still not synchronise or disconnects, try turning on the setting for Weak AC. This will compromise efficiency.
+If the generator will still not synchronise or disconnects, try turning on the setting for Weak AC. This will compromise efficiency, but allow for a wider variation in wave form distortion to be accepted.
 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.
@@ Line 102: / Line 109: @@
-===== 1.5 Loss of mains detection (LOM) =====
+===== 1.5 Loss of mains detection (LOM) (Only applicable to ESS systems) =====
+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, 'none' should be selected.
 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.
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 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, the total charge current possible will be less that the rated maximum charge current output of the charger (under normal conditions) when weak AC is disabled.
+Effectively, when Weak AC is enabled, the total charge current possible will be less that the rated maximum charge current output of the charger (under normal conditions).
@@ Line 184: / Line 193: @@
 ===== 4.1 PowerAssist =====
+{{::cleanshot_2024-07-17_at_14.54.43.jpg?600|}}
 The [[https://www.victronenergy.com/upload/documents/White-paper-Achieving-the-impossible-EN.pdf|PowerAssist feature]] can be extremely useful, however it restricts the minimum AC input current limit and this may exceed your generators ability to supply. The [[https://www.victronenergy.com/blog/2018/04/20/multiplus-quattro-inverter-chargers-improved-current-limits/|exact restriction varies between models - see here for the list.]]
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 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 "Assist current boost factor" setting as a multiple of the AC input current limit, and attempts to provide that much additional current.
+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://www.victronenergy.com/live/ve.bus:manual_parallel_and_three_phase_systems#configuration
+Described in the online training theory here:
+@ 38 minutes and 43 seconds - https://professional.victronenergy.com/online-training/20/
+Demonstrated in the 3 phase installation training here:
+@ 25 minutes - https://professional.victronenergy.com/online-training/21/
 ====== Still not connecting? ======
-If the unit is still not connecting, switch the Multi over to Charger only mode.
+If the unit is still not connecting,
+Check the VE.Bus Monitor and AC Input Connection timer
+{{::veconfige_107016584.png?direct|}}
+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.
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 [[https://www.victronenergy.com/upload/documents/White-paper-Using-the-MultiPlus-to-reduce-operating-cost-of-a-generator-EN.pdf|Using the Multiplus to reduce operating cost of a generator]] - Fuel Saving White-paper.
+[[https://www.victronenergy.com/upload/documents/VE_Marine_generator_test_RVA_07-jan-2008.pdf|Marine Generator Test]] - Detailed testing and the application of marine diesel powered generators in small hybrid power systems
 [[https://www.victronenergy.com/live/auto-generator-start-stop:start|Automatic Generator start/stop]] - Outline and reference for generator auto-start functionality in Victron systems.
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 [[https://www.victronenergy.com/blog/2018/04/20/multiplus-quattro-inverter-chargers-improved-current-limits/|MultiPlus & Quattro Inverter/Chargers: Minimum AC Input Current Limits]]
+[[https://community.victronenergy.com/questions/1702/multiplus-with-generator-and-residual-current-devi.html|Multiplus with Generator And Residual Current Devices]]
+===== Community Discussion on MultiPlus 2x120 and generator phase compatibility =====
+[[https://community.victronenergy.com/questions/110548/multiplus-ii-2x120-generator-compatibility.html|Multiplus II 2x120 generator compatibility]]
+[[https://community.victronenergy.com/questions/128941/multiplus-ii-2x120-with-onan-5500.html|Multiplus II 2x120 with onan 5500 generator]]
-===== DISQUS =====
-~~DISQUS~~