overvoltage- cascade component breakdown

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rick .w.
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overvoltage- cascade component breakdown

Post by rick .w. »

Does anyone have experience with mx60 overvoltage , and what components are usually affected . I would think it would generally be a usual set of components that fail , shutting down panel input. , the unit still functions in all aspects except it does not come out of sleep and sometimes reads ZZZZ, (same thing). I have received the diode ratings I needed from tech . To start; the readout states that there is 19 volts of panel power coming in when the panels are disconnected , so there is bleedback coming from the battery bank through 1 or more diodes . the relay does not engage likely due the the 19 volt dc false reading being lower than trigger voltage ( 24 v. battery bank) and that might be keeping it in sleep. there is no cap swelling , transformer overheating ,resistor burn, or transistor overheating signs. but if there is someone who knows of one of the discrete components that is generally affected by overvoltage , it would be great to know before installing the microdiodes ,reassembling and then having to tear it down again to start pulling components to test their values .///rick
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rick .w.
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My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
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Re: overvoltage- cascade component breakdown

Post by rick .w. »

looks like my assumptions are incorrect , the panel input is supposed to be 75% of battery voltage with battery on -panels off maybe I cooked the relay ?
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Re: overvoltage- cascade component breakdown

Post by sbrownian »

rick .w. wrote: Tue Feb 09, 2021 8:27 am looks like my assumptions are incorrect , the panel input is supposed to be 75% of battery voltage with battery on -panels off maybe I cooked the relay ?
I would be worried about whatever devices are doing the PWM switching. Not having a parts list or schematic, I would 'assume' that Outback uses IGBT or FET type devices to 'chop' the incoming power from the panels. Depending on the voltage ratings, they can be damaged by over voltage conditions.

BTW, be careful testing IGBT/FET devices. Due to the high impedance of the insulated gate, they can be damaged by mishandling.

Most of the ones I am familiar with come with a shorting wire or copper strip on the gate terminals, and you only remove it when making the gate drive connections.
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Re: overvoltage- cascade component breakdown

Post by raysun »

I agree with @sbrownian. The likely casualties would be the power FETs as well as possible support components like small electrolytic capacitors and partly failed resistors.

It would be very hard to be sure without going through a long, painful, and possibly fruitless process of component swapping.

The MX series are robust units under normal operation, but even then have a practical service life. The large electrolytic capacitor is a part that will age with time and use. In a catastrophic failure event, it may well be damaged too.

The age of the unit, the fact its been discontinued for a long time, and difficulty sourcing parts are not helpful factors in repairing it.
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rick .w.
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Joined: Mon Feb 08, 2021 8:49 am
My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
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Re: overvoltage- cascade component breakdown

Post by rick .w. »

YUP your right on the money , I blew all 13 field effect transistors (fdp 2432's mosfets) 35 bucks from Ontario semiconductor and a couple hrs to install new ones , and I should be back in business. caps and resistors in line are a-ok . might consider adding a source-gate Zener diodes to limit damage if it happens again. Taken on harder jobs , especially the ones that are buried n hardened plastic molds. thanks for the comments guys, I was beginning to think no one repaired anything anymore.////rick
raysun
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Re: overvoltage- cascade component breakdown

Post by raysun »

Good luck!

Of course, the predicate event, PV array overvoltage, should be addressed as well.
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rick .w.
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My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
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Re: overvoltage- cascade component breakdown

Post by rick .w. »

riding on the edge at 141vdc , then it went down to 24 below zero , full sun , 174vdc... just a hair over 150 haha, so I will be removing 1 , 21 volt panel from each series rack with the high voltage the mx60 was turning low light into real amps. but nuff of that time to be conservative with the equipment.
raysun
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Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: overvoltage- cascade component breakdown

Post by raysun »

rick .w. wrote: Tue Feb 09, 2021 9:38 pm riding on the edge at 141vdc , then it went down to 24 below zero , full sun , 174vdc... just a hair over 150 haha, so I will be removing 1 , 21 volt panel from each series rack with the high voltage the mx60 was turning low light into real amps. but nuff of that time to be conservative with the equipment.
The 150V rating is absolute maximum. The unit attempts shutdown at 145V. That, however, is to protect downstream components rather than the controller itself.

For a 24V battery, there is no need to have such high string voltages in order to charge efficiently. The major benefit is to reduce the amount of copper coming off the array, and combiner costs. Its a false economy, of course, if it burns up the controller.

Taking a single 21V panel off each string doesn't sound like enough to protect against the "worst case" voltage excursion.

The panel electrical specs and array geometry are not mentioned, but if it works out to create another string by equally reducing the existing strings and getting closer to 100V per string or less, you should be able to safely produce power when hell freezes over.
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rick .w.
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Posts: 14
Joined: Mon Feb 08, 2021 8:49 am
My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
Contact:

Re: overvoltage- cascade component breakdown

Post by rick .w. »

I will lower each panel rack down to 85 volts , when I was running the high voltage rack in overcast skies the mx 60 was turning input amperage into 3x the input value and pushing it into the batteries it would read 5 amps in 15 out even at low light .5 amps in would be 1.2 to 1.5 at times at 140 volts ??? was the readout incorrect? I never thought of checking accuracy with my fluke. the mppt cycle would pull the voltage down to around 70 to 80 volts when this occurred It ran like this for 15 yrs my gel cell ups valve regulated batteries are 10m yrs old and still going strong. I am in process of buying a brand new fm80 , does outback still honor the 5 year warranty? the old mx60 will be retired to powering the shop batteries.
raysun
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Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: overvoltage- cascade component breakdown

Post by raysun »

rick .w. wrote: Wed Feb 10, 2021 9:43 am I will lower each panel rack down to 85 volts , when I was running the high voltage rack in overcast skies the mx 60 was turning input amperage into 3x the input value and pushing it into the batteries it would read 5 amps in 15 out even at low light .5 amps in would be 1.2 to 1.5 at times at 140 volts ??? was the readout incorrect? I never thought of checking accuracy with my fluke. the mppt cycle would pull the voltage down to around 70 to 80 volts when this occurred It ran like this for 15 yrs my gel cell ups valve regulated batteries are 10m yrs old and still going strong. I am in process of buying a brand new fm80 , does outback still honor the 5 year warranty? the old mx60 will be retired to powering the shop batteries.
Outback's warranty is 5 years AFIK.

MPPT is just that, Maximum Power Point Tracking. The controller will adjust the array power accepted to maximum at each "sweep".

140V must have been close to V(oc) so little, if any current would be flowing in an essentially open circuit condition.

The IN and OUT equivalence are easiest to compare in watts. IN voltage x IN amps is the measure of power from the array. OUT voltage (the battery voltage) × OUT amps = charge current to the battery. There will be a small amount of conversion loss, but all in all W(in) and W(out) should be nearly equal.

Reconfiguring the array will have the effect of lowering V(in) and raising I(in).
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Re: overvoltage- cascade component breakdown

Post by JRHill »

This brings on a question that I have pondered but not pursued - its just a curiosity.

For example, I used to have a sticky note where I logged record setting kW from the panel arrays. I didn't note the voltages. The sticky note lost its sticky and got away from me but as I recall, once, I almost hit rated output. a few other times almost. In more recent years I've never come within 80% of the kW rated output. Part of that is the slloooww growing oak trees right at the house which block a bit more light than originally. Also the fir trees at the top of the canyon which increasingly block more light in the low temperature season which would probably be the the high voltage event.

So here is the question: as the panels age (mine are at 12 years), does the output affect the current generation or the voltage they can deliver, or both? Maybe this question is specific to models and/or mfgrs and not a generalized? I'm wondering what y'all have noticed.
sbrownian
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Re: overvoltage- cascade component breakdown

Post by sbrownian »

A bit 'long haired' reading, but very thorough as it addresses the various types of panel construction, and makes allowances for technological improvement since 2000...

Photovoltaic Degradation Rates — An Analytical Review

https://www.nrel.gov/docs/fy12osti/51664.pdf
JRHill
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Re: overvoltage- cascade component breakdown

Post by JRHill »

sbrownian wrote: Wed Feb 10, 2021 11:33 am A bit 'long haired' reading, but very thorough as it addresses the various types of panel construction, and makes allowances for technological improvement since 2000...

Photovoltaic Degradation Rates — An Analytical Review

https://www.nrel.gov/docs/fy12osti/51664.pdf
Wow. That's a read with a fresh pot of coffee. I scanned it but it seems the aggregate of amps and volts and I couldn't find any reference to either being paramount. Esp with the various technologies of panel types. I don't want to distract from the subject of this thread. Thx Sbrownian for the resource.
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Re: overvoltage- cascade component breakdown

Post by raysun »

How about us that have to physically derate arrays because the panels will, on occasion, put out MORE power than STC rating?

I've seen this on several occasions, and even with derating panel output due to heating have seen actual output over 10% above STC. When I put up my new 440W REC Alphas, I had a 10 panel array, figuring I could "cheat" with the battery never going below 50V. The gods were amused. It wasn't even a week before I saw a sustained 5200W off the array! I put an end to that foolishness right away. Now I have 8 panel arrays. Gotta make do with 3520W per.
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Re: overvoltage- cascade component breakdown

Post by JRHill »

raysun wrote: Wed Feb 10, 2021 12:26 pm How about us that have to physically derate arrays because the panels will, on occasion, put out MORE power than STC rating?

I've seen this on several occasions, and even with derating panel output due to heating have seen actual output over 10% above STC. When I put up my new 440W REC Alphas, I had a 10 panel array, figuring I could "cheat" with the battery never going below 50V. The gods were amused. It wasn't even a week before I saw a sustained 5200W off the array! I put an end to that foolishness right away. Now I have 8 panel arrays. Gotta make do with 3520W per.
How old were your panels when you swapped them out for the 440s? (The 440 number sounds cool. Vroom).

When I was watching and logging panel output it had to be by that day before midnight. I could see the max for the day in current and kW but not voltage. Seems I had to be right at the Mate3 at the momentary time of VOC. Even then, OpticsRE doesn't have the info that I know of even from the reports. Maybe its in there and I haven't found it.
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Re: overvoltage- cascade component breakdown

Post by raysun »

5 years old. The new panels were $200 ea. I sold the 24 old panels for $100 ea.

Everybody was happy.
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Re: overvoltage- cascade component breakdown

Post by JRHill »

raysun wrote: Wed Feb 10, 2021 1:04 pm 5 years old. The new panels were $200 ea. I sold the 24 old panels for $100 ea.

Everybody was happy.
I have pondered this for quite some time. I could add panels and another CC. But when I really need the power there isn't any sunlight. So add as I will there would be little gain. Then in spring/summer/fall I have all the solar I need with what is in place. The added CC and panels would just get me to full faster and I don't need it then. So its really about efficiency with the generator and I love those PHIs for being tolerant of short charging. This is where the FLAs cost me a lot of dollars in years past and this is where the PHIs are really valuable.
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Outback IBR3 battery enclosure
Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: overvoltage- cascade component breakdown

Post by raysun »

Yes, charge efficiency and PSoC operation are blessings of lithium over lead, but we wander off topic...
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rick .w.
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Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
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Re: overvoltage- cascade component breakdown

Post by rick .w. »

still waiting on my capacitors from digikey for the mx60 they use fedex and it's been over 1 week , think I will find a component supplier that uses postal mail. they deliver rain snow sleet or shine the mail always gets through . my 3 caps and 20 mosfets are stuck in fargo north Dakota , with fedex ,because it's cold out, have to go back to buying from Electro sonic. and the FM80 is on route with ups. I'm missing a lot of sunny days , and wasting diesel on my 1965 lister one lunger . I have to burn 1 gallon every 2 days. And also I brought each rack of 100 watt panels down to a safe 60 volts give or take, with a safe 35 or so amp total from the 2000 watts , but I do have a hybrid rack of 300 watt panels I cut in when needed that jacks the amperage another 20 amps.
raysun
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Suniva 330 watt panels (12 - 6 strings of 2 in series)
Hyundai 355 watt panels (6 - 3 strings of 2 in series)
Honda EU7000is gas fuel generator

Re: overvoltage- cascade component breakdown

Post by raysun »

A gallon of off-road diesel every two days? I bet there's some electricity consumers in Texas that would be thrilled to swap power bills with you. 😉

Keeping the PV voltages in line will go a long way toward preserving charge controller well-being.
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rick .w.
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Joined: Mon Feb 08, 2021 8:49 am
My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
Contact:

Re: overvoltage- cascade component breakdown

Post by rick .w. »

ya, I heard some of them got a 17000.00 dollar electricity bill this month when the cost of a kw went from 20 cents to 400.oo dollars . that's why I moved to the middle of nowhere and built my little refuge. 3 backup m1 cyl diesels I gas 4300 watt gas backup and big daddy 1 -38 kw dorman 4cyl diesel 3 phase 120 /220 with 700 gallons of backup diesel. just in case
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Had 1200 Ahr FLA Locomotive batts
Just replaced with
2 x 300 Ah ReLion Lithium packs
MUCH more efficient!!
Location: Central Washington State

Re: overvoltage- cascade component breakdown

Post by sbrownian »

Make sure you treat that diesel. There are a few "bugs" out there that like the stuff well enough to grow in it...
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Re: overvoltage- cascade component breakdown

Post by JRHill »

I love the smell of diesel in the morning. It smells like something is gonna get done.
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Re: overvoltage- cascade component breakdown

Post by JRHill »

BTW, Rick, what is the "bank powered desulfation block"? I know the battery minder is powered by the battery but those can only handle one or two at a time. Do you have something that conditions a bigger bank?
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rick .w.
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Joined: Mon Feb 08, 2021 8:49 am
My RE system: 2000 watts of panels @45 amps into 24volt bat bank of 40 -12 volt gel cell sealed lead acid valve regulated batteries. with 250.00 , bank powered desulfation block, controlled by MX60 bought new ( 900+ back in the day here in Canada)
Location: 2 miles north of U.S border/ 41 acres 4 miles from pavement,on blizzard mtn in the rockies
Contact:

Re: overvoltage- cascade component breakdown

Post by rick .w. »

the desulfator is a forklift battery saver a BLS 24/36 volt MULTI F you can get 48 v also they go for around 220 to 250.00 u.s. they do a great job I connect the clamps to the pos and neg lugs just before the breaker going into the solar controller they have kept 40 - 80 pound valve regulated mainframe computer backup batteries clean for 10 yrs. and they are still going strong. but they are about due for a disconnect and load test. even sealed gel cells sometimes (rarely) need a touch up of acid I use straight sulphuric acid on the gel cells , which is really 50% and it just remoistens up the silica.. In regular lead acid flooded batteries I just dump all the acid out and fill them up with Epsom salts& water, 1 in my truck was done 2 yrs ago and is still going good
Last edited by rick .w. on Thu Feb 25, 2021 8:19 pm, edited 2 times in total.
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