ve.bus:grid-codes-and-loss-of-mains-detection
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ve.bus:grid-codes-and-loss-of-mains-detection [2020-07-20 16:48] – [LOM detection Type A and Type B] mvader | ve.bus:grid-codes-and-loss-of-mains-detection [2020-07-21 14:52] – [2.5 How to identify if LOM detection causes issues?] mvader | ||
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All countries have their own legislation and therewith their own requirements with regards to the speed of Loss of mains detection, under & over voltages, accepted ramp times, and so forth. To make an installation comply to local regulations, | All countries have their own legislation and therewith their own requirements with regards to the speed of Loss of mains detection, under & over voltages, accepted ramp times, and so forth. To make an installation comply to local regulations, | ||
- | The exact requirements differ widely between the countries. For example the normal Multis, Quattros and MultiCompacts are certified for use in the UK. For other countries, Germany for example, only the MultiGrid | + | The exact requirements differ widely between the countries. For example the normal Multis, Quattros and MultiCompacts are certified for use in the UK. For other countries, Germany for example, only the MultiPlus-II |
+ | In certain situations, the inverter/ | ||
+ | |||
+ | Make sure to also read [[ess: | ||
===== 2. Loss of mains detection (LOM) ===== | ===== 2. Loss of mains detection (LOM) ===== | ||
- | ==== What is LOM detection? ==== | + | ==== 2.1 What is LOM detection? ==== |
LOM is an automatic process that detects a change and so loss of the mains/ | LOM is an automatic process that detects a change and so loss of the mains/ | ||
- | ==== Why is LOM detection required? ==== | + | ==== 2.2 Why is LOM detection required? ==== |
The purpose of LOM is to detect that the Multi is no longer connected to the mains. Be that a generator or the grid. In such case, the Multi needs to open its back-feed relay. Not doing that would be unsafe. Imagine an electrician working on the street, and disconnecting a house. He then needs to be able to safely work on the wiring from the house. | The purpose of LOM is to detect that the Multi is no longer connected to the mains. Be that a generator or the grid. In such case, the Multi needs to open its back-feed relay. Not doing that would be unsafe. Imagine an electrician working on the street, and disconnecting a house. He then needs to be able to safely work on the wiring from the house. | ||
- | ==== How does LOM detection relate to overload shutdowns? ==== | + | ==== 2.3 How does LOM detection relate to overload shutdowns? ==== |
To detect a loss of mains, the inverter/ | To detect a loss of mains, the inverter/ | ||
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When connected to a generator, or to a grid with a long extension cable or long ‘last mile’ cable, the pushing and pulling on the grid does create high currents, and as a result the inverter/ | When connected to a generator, or to a grid with a long extension cable or long ‘last mile’ cable, the pushing and pulling on the grid does create high currents, and as a result the inverter/ | ||
- | ==== How does LOM detection relate to passthru? ==== | + | ==== 2.4 How does LOM detection relate to passthru? ==== |
Similar to above section about overload, a too weak connection to the utility can cause continuous increases and decreases in frequency, not resulting in overload but still resulting in continuous shifts in frequency. | Similar to above section about overload, a too weak connection to the utility can cause continuous increases and decreases in frequency, not resulting in overload but still resulting in continuous shifts in frequency. | ||
This (can) cause a safety mechanism to activate which temporarily disables feed-in. | This (can) cause a safety mechanism to activate which temporarily disables feed-in. | ||
- | ==== How to identify if LOM detection causes issues? ==== | + | |
+ | ==== 2.5 How to identify if LOM detection causes issues? ==== | ||
By temporarily disabling the LOM, one can identify that the LOM is causing an issue. Here is how to disable it: | By temporarily disabling the LOM, one can identify that the LOM is causing an issue. Here is how to disable it: | ||
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Open VEConfigure, | Open VEConfigure, | ||
- | Save the settings, and wait to see if this helps. In case it does help, see next section. | + | Save the settings, and wait to see if this helps. |
+ | |||
+ | In case disabling LOM solves the issue, one solution is to make for a better (lower impedance) connection to the utility. In case that can't be improved, another solution is to keep LOM disabled and install an external anti-islanding safety devices (ENS). For example from Ziehl, or another brand. They have different techniques of detecting a loss of mains, and can (often) therefor work without any problem. Detailed instructions for permanently disabling the built-in LOM feature are in the next chapter. | ||
NOTE: for LOM to cause issues is really rare. Its documented in detail on this page to help installations where it does cause an issue, but its really rather rare to happen in the first place. Do make sure to read the [[ess: | NOTE: for LOM to cause issues is really rare. Its documented in detail on this page to help installations where it does cause an issue, but its really rather rare to happen in the first place. Do make sure to read the [[ess: | ||
- | ==== What to do when LOM detection causes issues? ==== | ||
- | The previous section explains how to identify if LOM causes an issue. It can cause overload shutdowns, and it can also cause a system to frequently show " | + | ==== 2.6 Disabling |
- | The solution is then to make for a better connection | + | There are a few situations in which LOM needs to be disabled: |
+ | - For certain generators | ||
+ | - In case LOM causes Overload, Passthru or other issues while connected to the utility (see above) | ||
+ | To disable LOM, use VEConfigure and go to the Grid tab. A password is required to choose " | ||
- | ==== LOM detection Type A and Type B ==== | + | === Safety notes - Generator |
- | Within the Victron product range, there are two types of LOM detection available **Type A** and **Type B**. | + | There is no regulatory need to install external anti-islanding equipment when disabling |
- | All recent certified grid codes use Type B. On the MultiPlus-II models, **all** grid codes use Type B, and Type B is no longer used. | + | === Safety notes - Utility connection === |
- | **Type A** is the strongest form of LOM detection resulting in the quickest detection time. It requires a low impedance connection | + | Disabling |
- | **Type B** has a more soft approach and a slightly longer detection time. **Type B** has been type tested and approved for most Multi/ | + | Make sure to comply to local rules & regulations |
- | On generators, and also with installations having | + | |
- | For generators on which also **Type B** does not work, see Disabling | + | === Screenshot of LOM settings === |
+ | {{ : | ||
+ | |||
+ | ==== 2.7 Background: LOM detection Type A and Type B ==== | ||
+ | |||
+ | Within the Victron product range, there are two types of LOM detection available: Type A and Type B. | ||
+ | |||
+ | All recent certified grid codes use Type B. On the MultiPlus-II models, **all** grid codes use Type B, and Type A is no longer used. | ||
- | ==== Disabling | + | **Type A** is the strongest form of LOM detection resulting in the quickest detection time. It requires a low impedance connection to the grid (short, well sized cables). LOM Type A will not work with generators. |
- | Besides choosing | + | **Type B** has a more soft approach |
- | Note disabling the LOM on an input connected to the grid is only allowed when other external safety equipment is installed. | + | On generators, and also with installations having a relatively high impedance mains connection, Type B will work better than Type A. |
- | Disabling | + | For generators on which also Type B does not work, see Disabling LOM. |
- | ==== Grid codes and Type A and Type B LOM ==== | + | ==== 2.8 Grid codes and Type A and Type B LOM ==== |
Some Grid codes will use Type A and others will use Type B. The Type that has been tested and approved for compliancy is marked with __grid code compliant__. See below screenshot. | Some Grid codes will use Type A and others will use Type B. The Type that has been tested and approved for compliancy is marked with __grid code compliant__. See below screenshot. | ||
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{{ : | {{ : | ||
+ | |||
===== 3. Example configuration in VEConfigure ===== | ===== 3. Example configuration in VEConfigure ===== | ||
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Some, bigger or better quality generators, will be able to work with LOM **Type B**. For other less stable generators it will be required to disable LOM entirely. In that case make the installation such that it is still safe: no simple extensions cords, use enclosed wiring cabinets with warnings on the outside and/or an external ENS. | Some, bigger or better quality generators, will be able to work with LOM **Type B**. For other less stable generators it will be required to disable LOM entirely. In that case make the installation such that it is still safe: no simple extensions cords, use enclosed wiring cabinets with warnings on the outside and/or an external ENS. | ||
- | More information | + | More information |
==== Q4: I use ESS, but have disabled feed-back, is a grid-code still required? ==== | ==== Q4: I use ESS, but have disabled feed-back, is a grid-code still required? ==== | ||
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- | ===== DISQUS ===== | ||
- | ~~DISQUS~~ | ||
ve.bus/grid-codes-and-loss-of-mains-detection.txt · Last modified: 2022-10-31 23:41 by mvader