New off grid 48v build

Bigfillly

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Aug 20, 2017
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Quick update,
When the inverter output is connected to the grid, the inverter goes up to 110% usage and trips the main switch out on the consumer box, it come up with code (07) on the inverter too,
Can anyone explain what is wrong with it please,
Thanks,
phil.
 

not2bme

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did I read that right? 'When the inverter output is connected to the grid'?

So you're outputting the inverter power into the breaker in your house? Your PIP is not a grid-tie inverter. You can't send power back into your mains. It won't work.
 

Bigfillly

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Just to clear things up,
Im not connecting it myself, the electrician that came to connect it couldnt stop it tripping the switch, he did in the end but he needs to get a few breakers for it to work,
The last thing I want to do is give the power back to the grid, I ment when the inverter output is connected to my consumer box where the trip switches are,
Does that make better sense :-D
 

completelycharged

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Caution on overloading the PIP if you have wired it into the consumer unit. If you can post a wiring diagram or indication on the connection it might help as it should be wired into a separate unit before the consumer unit if you are using it to feed the consumer unit (I was a sparky for 11 years in the UK...).


Should ideally be something closer to this :


image_sjampi.jpg


That would allow the PIP to charge from AC and still supply your house loads on consumer unit 2.

Consumer unit 1 can just be a 16A switched fuse.

STB Block as they were called is just a connector block for meter tails / upto 35mm2 connections that is backed by the 100A incomming fuse..


Guessing it might be wired something like this

image_dmkmjm.jpg
 

Korishan

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I'm guessing "Consumer Unit" is another name for the Main Breaker/Fuse Panel, or at least the 2nd one after the Main?
 

Bigfillly

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I see, I get what your saying now COMPLETE CHARGED,its a bit of messing about but if it has to be that way, then it has to be that way, I never realised this inverter couldnt be connected to the consumer unit (korishan, you are correct)
Ill have the sockets, lights and shower from the inverter, Ill leave the cooker straight from the grid/mains,
Thanks for the great info, Ive passed the info onto the electrician, Ill update when hes been again,
Phil.
 

completelycharged

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Shower will overload the inverter as they are usually 7kW minimum, unless it is a booster pump in which case the initial surge may cause issues.

"Consumer Unit" is the UK name for the breaker box...

Normally the connections in the UK are :

Mains Cable -> 100A Fuse -> Meter -> STB Blocks -> Consumer Unit

The 100A Fuse is owned by the distribution company and the meter is owned by either the Distribution company or a Metering supplier under a sub contract, or that's how is was...
 

Korishan

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Ahh, gotcha. Here in the US we have Mains -> Meter Box -> Mains Breaker (which can have sub-breakers in it) -> House Sub-Panel (which has the rest of the breakers for the house in it)
The Mains meter can either be on a pole or attached to the outside of the house and is not locked at all for emergency cutoff. The sub-Panel can be inside the dwelling.
Here the meter is owned by the power company (in most cases, not sure if there are times when they aren't)

Thanks for the UK education :)
 

not2bme

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Still doesn't explain why your electrician doesn't know why it's tripping. If he isolated the "consumer unit' to only the pip output then he should have realized that the PIP is only a 4kw unit and the whole house can't run on 4kw if you look at all the appliances it has. The only way he can get confused if he thinks it's a grid tie unit and that all he has to do is hook the pip output up to the "consumer unit" like all grid-tie units do (or so it's done in the US for most typical installs). That is backfeeding into the grid even if you're thinking that the "consumer unit" is isolated from the grid, which it isn't. If you have only one "consumer unit" then you need to look into getting another "consumer unit" that is isolated just for your PIP output.
 

SilverNodashi

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not2bme said:
Still doesn't explain why your electrician doesn't know why it's tripping. If he isolated the "consumer unit' to only the pip output then he should have realized that the PIP is only a 4kw unit and the whole house can't run on 4kw if you look at all the appliances it has. The only way he can get confused if he thinks it's a grid tie unit and that all he has to do is hook the pip output up to the "consumer unit" like all grid-tie units do (or so it's done in the US for most typical installs). That is backfeeding into the grid even if you're thinking that the "consumer unit" is isolated from the grid, which it isn't. If you have only one "consumer unit" then you need to look into getting another "consumer unit" that is isolated just for your PIP output.

Unless he has a "floating ground" fault, which often happens if electricians install something like a PIP4048 onto a DB board, but want to leave some appliances on the municipal mains.
 

Bigfillly

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I thank everyone that has help me along the way, Ive learnt a lot and wouldnt have got there without all you guys, so THANK YOU ALL,
its all hooked up, the lights and sockets are on the second consumer unit, Ive also got a changeover switch for if theres no solar and low batteries, is there really any need for it? as the pip has a grid input and will bypass if it needs to,
Also is there anyway to connect my iPad to the inverter, so I can check on it from my house?
Thanks.
 

Bigfillly

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Hi all again,
Yesterday I had my morning check on the system and noticed that my array to the pip had no watts coming from it, the sun was on them well and the volts were good (I think around 70v) but no watts, so no charge at all, I swapped the array over to a spare pcm 60x and still no watts,
What can I check for?
Thanks,
Phil.
 

Bigfillly

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I’m thinking maybe one panel is defective and bringing the others down, any thoughts?
 

ajw22

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I think it's very unlikely that a PV panel shows normal voltage, but is incapable of supplying any current at all.
Does the PCM60X show 70V on the input side? If not, perhaps the PV breaker could be broken inside. Or a broken fuse/breaker on the output side.
 

OffGridInTheCity

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I think it's very unlikely that a PV panel shows normal voltage, but is incapable of supplying any current at all.
Does the PCM60X show 70V on the input side? If not, perhaps the PV breaker could be broken inside. Or a broken fuse/breaker on the output side.
Agree @ajw22. I recently bought/tested some used panels - and found that the 'broken ones' (1 diode blown) had significantly lower voltage that specs / similar panels. If there's a raw problem with the panels, the voltage will show this.

Of course its important to know what's normal so you can recognize the drop. :)
 

Bigfillly

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Indeed the pcm60x is showing the volts are fine, it has watts but they are very low, 300w with good bright sun and the array is 8x250w, I have another pcm60x with 8x260w and in the same sun they show 3 times as much watts, after about an hour of sun the watts go down to 40w,
I’ll have a tear down and test each one, I’ll update you all what I find out,
Thanks very much,
Phil.
 

ajw22

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Hard to go on without pictures or little information on how the panels are connected. If the voltage is fine, but output suddenly dropped to 1/3rd, then my suspect #1 would be the combiner box/adapter for the panels. It's the best season now for PV output (good sun angle & cool), so it's possible some breaker/fuse inside the combiner box tripped/blew, or maybe it was undersized and something melted. Most MC4 connectors are only rated for 30Amps 20Amps.
Or maybe some of the wires got a little loose. Tends to happen with stranded wires in screw terminals (always use ferrules!).
 
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