drafts:mppt_faq
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drafts:mppt_faq [2017-08-12 07:58] – [Solar Charger is not charging] mvader | drafts:mppt_faq [2019-06-05 15:59] – [Q8: Can I connect different panels to the same charge controller?] mvader | ||
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====== MPPT FAQ ====== | ====== MPPT FAQ ====== | ||
- | ==== 75/15 and 100/15 cannot be controlled by a BMS, what now? ==== | + | See also [[victronconnect: |
+ | ==== Q1: I want to size or oversize my PV array, how can I do this? ==== | ||
- | The reason is that the RX pin is already used to the battery life on/off selection with the jumper. So therefore it is unfortunately not possible to control these two models with the VE.Direct .. remote on/off cable [link]. The solutions is buy the next model in line: the MPPT 100/30. | + | See the blogpost [[https://www.victronenergy.com/blog/ |
- | ==== My MPPT is only showing voltage readings, not currents and also no Watts? ==== | + | ==== Q2: 75/10, 75/15 and 100/15 cannot be controlled by a BMS, what now? ==== |
+ | |||
+ | By default the RX pin is already used to control the battery life on/off selection with the jumper. Use VictronConnect to change the function of the RX pin to remote on/off to enable BMS control. See | ||
+ | [[https:// | ||
+ | |||
+ | ==== Q3: My MPPT is only showing voltage readings, not currents and also no Watts? ==== | ||
Make sure to *not* connect PV minus to the battery. See the manual. | Make sure to *not* connect PV minus to the battery. See the manual. | ||
- | ==== Can the output of the MPPT be used as a power supply, thus without batteries? ==== | + | ==== Q4: Can the output of the MPPT be used as a power supply, thus without batteries? ==== |
The answer is; it depends on the type of load. | The answer is; it depends on the type of load. | ||
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Loads where under voltage does not apply, like light globes, can be operated without any problems. | Loads where under voltage does not apply, like light globes, can be operated without any problems. | ||
- | ==== I want to over dimension | + | ==== Q5: What about grounding one of the PV array poles? ==== |
- | Over-dimensioning a PV array is installing more Watt-peak than the maximum charge power of the chosen MPPT charge controller. A common reason to over dimension | + | The MPPT is non isolated, meaning that the minus of the PV input is at the same potential as the minus of the battery output. |
- | How to determine how far you can over dimension | + | Grounding is always done at one point only, to avoid ground currents. For a battery system, grounding must be done at the battery. |
- | There are two limits, when determining the maximum array size that can be connected to an MPPT: | + | ==== Q6: The Solar Charger is not working ==== |
- | - The Maximum | + | 1. Check that the PV voltage |
- | - The Maximum PV short circuit current (Isc at STC) | + | |
- | Both values are specified in the datasheets of all our MPPT Solar Chargers. Those two ratings of the PV array must not exceed these MPPT limits. | + | Or measure |
- | Note that these two maximum ratings must **not** be multiplied | + | 2. For models with a Remote on/off switch (a green two pole connector, labelled Remote L H), check that the jumper is in. L and H need to be shorted for the unit to switch on. Only the large models have this connector, see datasheet for details. |
- | === Determining the maximum PV open circuit voltage === | + | 3. Check that the battery |
- | First look on the datasheets of the solar panels to see what their maximum open circuit voltage is. Then multiply | + | |
- | === Determining the maximum PV short circuit current === | + | 4. Check for [[: |
- | Get the maximum PV short circuit current from the PV Panel datasheet. Multiply by the number of panels in parallel in the array. Having more panels in series does not change the number. | + | |
- | The result of the calculation may not exceed | + | If all above is fine, and still the unit does not operate, contact a dealer to have the unit tested. |
+ | ==== Q7: Can I use the MPPT Solar Charger as DC-DC charger? ==== | ||
- | === What about grounding one of the PV array poles? === | + | For example to charge a 12 Volt battery from a 24V battery bank? |
- | The MPPT is non isolated, meaning that the minus of the PV input is at the same potential as the minus of the battery output. | + | No. |
- | Grounding is always done at one point only, to avoid ground currents. For a battery system, grounding must be done at the battery. | + | ==== Q8: Can I connect different panels |
- | ==== Solar Charger is not charging ==== | + | No. Under no circumstances. |
- | 1. Check that the PV voltage is high enough compared to the battery voltage. Either read it with a remote panel or VictronConnect. Or measure, on the terminals on the charger!, not elsewhere and mind fuses, with a Volt meter. | + | ==== Q9: Can I use panels with optimisers? |
- | + | ||
- | 2. For models with a Remote on/off switch (a green two pole connector, labelled Remote L H), check that the jumper is in. L and H need to be shorted for the unit to switch on. Only the large models have this connector, see datasheet for details. | + | |
- | + | ||
- | 3. Check that the battery voltage is set properly in the settings (12/ | + | |
- | + | ||
- | 4. Check for [[: | + | |
- | + | ||
- | If all above is fine, and still the unit does not operate, contact a dealer to have the unit tested. | + | |
- | ===== DISQUS Comments ===== | + | |
+ | No. | ||
+ | ===== DISQUS ===== | ||
~~DISQUS~~ | ~~DISQUS~~ | ||
drafts/mppt_faq.txt · Last modified: 2021-09-30 07:18 by guystewart