June 6, 20197 yr So finally up and running today. Roof space was an issue so I went North, East and West. Running 16X335W Canadians in 2SP2 on a 150/35 North and 2S6P on 150/100 East/West. (Will see how that pans out) Multiplus II - 5KVA with Venus. 2X Pylons US3000 ** Things that still need to be done - further labeling and some T-piece trunking to clean it up a bit better. Extractor fan to help get rid of the heat. *** Things I should of done.. gone for a 3-row DB, would of looked a bit better. First Picture.. before..
June 7, 20197 yr Having done similar, my "cupboard" is open bottom and top, I would check the temp of the devices because the higher the temp in the cupboard, the more the inverter will derate it's max power. In summer I hear my inverters fan running frequently. Now that it is cooler, hardly ever. Keep a hand on the MPPT - mine was hotter than a aquarium thermometer could measure, even the Prestic became goo after a while, all adding towards increasing the temp in the "cupboard".
June 7, 20197 yr 5 minutes ago, The Terrible Triplett said: Keep a hand on the MPPT - mine was hotter than a aquarium thermometer could measure, even the Prestic became goo after a while, all adding towards increasing the temp in the "cupboard". If it does not go "psssh" when I lick my finger and touch it.... tis okay! Okay, I am kidding. Although that is pretty much how I check other power electronics. If you put a wet finger on it and the wet surface evaporates immediately, then it is too hot. For the MPPT, I work from the principle that if you can touch it and don't find yourself wanting to to stop touching it immediately, it's below 60°C and it's not really a reason for too much concern. It does start to derate above 40°C, so cooler is always better. Just not worth it to add a large fan if you're not getting the energy back required for said fan.
June 7, 20197 yr Author The fan is around 40w, will see how it goes. Today is the first time it has been up since the morning. Was getting between 1500-1800w from the PV at about 8, which was used to charge and the geyser kicked in at 9:15, been cruising at 2600w since then. I am not sure what to make of the East/West config and what I should be expecting to get.
June 7, 20197 yr 53 minutes ago, plonkster said: it's below 60°C Mine was above 60°C. 55 minutes ago, plonkster said: Just not worth it to add a large fan if you're not getting the energy back required for said fan. True. I put a small AC fan on a R199 AC timer that switched the small fan on from 10am and off at 5pm, to circulate the air more aggressively in the cupboard, even though the top and bottom was open. Fall and winter the fan is off. Problem solved. Note: I KNOW Victron can take it, but why do it if we don't need to do it. The more moderate the temps are, the longer it lasts. Say as is Victron lasts +-15 years but with some air circulation, maybe +-25 years. 🙂 Ps. Remember my "air cooled" install in the window using burglar bars more effectively, the one that made people freak out? 🤣 But let me say this, that Phoenix seldom if ever had the fan on!!! MPPT's always cool to the touch. From here - off-grid - and photo angle so that it looks even more worrisome - even thought it had all the protections in place: To here - bottom and top open - wife is completely happy as this is at a major though fare junction in the house that has a lot of traffic:
June 11, 20197 yr Author So after running a few days.. I can report back that it seems to be working OKish. The 4 Panels North peak at around 1100w. The 6 East/ 6 West configuration is running 3 in series, which seems to be making the difference, get a peak of 2200w. Not sure how to determine what yield I should be getting. 80/85% of rated power? I have a question around the Pylons and the MPPT max amps, seems they have set the MPPT's to not exceed the 37amps per pylon module. I thought that something else would manage this, like the BMS or the settings on the Inverter on setup?
June 11, 20197 yr 44 minutes ago, PaBz0r said: ... , seems they have set the MPPT's to not exceed the 37amps per pylon module. ... I'm under correction here as I don't have Pylon's but I have had a under preforming situation. Had to set my MPPT to the max it can charge, I limit the VenusGX to the max the system must charge the batteries. Only issue is when the VenusGX is off, my batts will get hit with the full power of the array / MPPT. Bleh - I just need to switch the panels off first or only do any changes at night. 🙂 If you limit the MPPT then the system under preforms. @plonkster can add a lot more to my bare minimum explanation.
June 11, 20197 yr Author 18 minutes ago, The Terrible Triplett said: Only issue is when the VenusGX is off, my batts will get hit with the full power of the array / MPPT. Bleh - I just need to switch the panels off first or only do any changes at night. 🙂 If you limit the MPPT then the system under preforms. Thats how they explained it to me as well. It was set up to limit each on 35A. I have changed the 150/35 to Max 25A, thats based on where it peaked the last few days, didn't get too close to that. I have upped the 150/100 to 45, which brings me back to 70. I have left some room to play around with. Unfortunately I calculated the East/West based on 12 panels, so I guess the sun hitting 6 optimally at a time I could get away with a much smaller MPPT.
June 11, 20197 yr 30 minutes ago, The Terrible Triplett said: Had to set my MPPT to the max it can charge, I limit the VenusGX to the max the system must charge the batteries. Yup. The rule is that the limit on the hardware is always respected, we never override that. What it means is you still have to respect certain limits in PV-array vs battery bank sizes. If you need to bring in large amounts of PV (for loads) but you only want a small amount of backup, it is much better to use a PV-inverter (aka grid-tied inverter) instead of an MPPT.
June 11, 20197 yr 18 minutes ago, plonkster said: The rule is ... You know me ... rules are like bones. They are meant to be broken - with the accompanying Dr's bill off course. 19 minutes ago, plonkster said: ... , it is much better to use a PV-inverter (aka grid-tied inverter) instead of an MPPT. Bleh ... they must just make 12/24v lithium's affordable. Then my problem is solved. 😜 On a more serious not ... you are right. Be wise.
June 13, 20197 yr On 2019/06/11 at 10:46 AM, PaBz0r said: Thats how they explained it to me as well. It was set up to limit each on 35A. I have changed the 150/35 to Max 25A, thats based on where it peaked the last few days, didn't get too close to that. I have upped the 150/100 to 45, which brings me back to 70. I have left some room to play around with. Unfortunately I calculated the East/West based on 12 panels, so I guess the sun hitting 6 optimally at a time I could get away with a much smaller MPPT. As I was advised, on the system open the taps, the Pylontech have onboard management that will protect the batteries. Welcome to team blue. G
June 13, 20197 yr Author 1 hour ago, georgelza said: As I was advised, on the system open the taps, the Pylontech have onboard management that will protect the batteries. Welcome to team blue. G Not sure how it will react when this happens, perhaps shutdown? Which could be an issue
June 13, 20197 yr I'm saying, have the MPPt get what ever it can from the PV, and then past on to the batteries whatever it can, I've been told the Pylontechs will throttle their side anyhow, if it's getting more than it can handle. G
June 13, 20197 yr 2 hours ago, georgelza said: throttle Not really. If you overdo it they switch off. And leave you in darkness. But they do allow you a lot of margin. You can charge up to 2C for short periods, and you can discharge at the same high level for about a minute or so. The point is that the batteries will not allow you to abuse them, they will protect themselves if you try to. So you don't have to be overly concerned with sticking exactly to the charge/discharge instructions the BMS sends (though it helps of course). The only important thing to note: Don't exceed 54V. The Pylontech BMS has no grace on that side, if you exceed 54V it switches off immediately.
June 14, 20197 yr "the batteries will not allow you to abuse them, they will protect themselves if you try to." And so it begins, next stop Skynet..... LOL.
June 14, 20197 yr 16 hours ago, plonkster said: The point is that the batteries will not allow you to abuse them, they will protect themselves if you try to. So what happens if the BMS fails? EDIT: Question comes from my own personal "SURPRISE!!!" experiences. Edited June 14, 20197 yr by Guest
June 14, 20197 yr 4 hours ago, The Terrible Triplett said: So what happens if the BMS fails? Then you have a warranty claim 🙂
June 14, 20197 yr 48 minutes ago, plonkster said: Then you have a warranty claim 🙂 No fireworks? I want a refund then! (cwl) No seriously, if the BMS fails, I supposed all goes off?
June 14, 20197 yr Author 20 minutes ago, The Terrible Triplett said: No fireworks? I want a refund then! (cwl) No seriously, if the BMS fails, I supposed all goes off? Hopefully...
June 14, 20197 yr 2 hours ago, The Terrible Triplett said: No seriously, if the BMS fails, I supposed all goes off? I don't know. If you know your stuff you design it so that either there is some redundancy, or so that it fails safe (ie a BMS failure causes the battery to disconnect and protect the cells).
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