Re: Solar Panel coming through roof with cable

by Peter Brown Thu Nov 27, 2014 12:35 pm

Paulmold wrote:Couldn't you simply take a voltage reading directly from a 12v socket, then cover the panel and take another reading allowing time for the battery to settle. Then uncover and take another reading. Wouldn't that show if the panel was working, irrespective of the Sargent panel.

It will work but the battery smooth's out the change in voltage so you would really need a very sunny day to see the change in voltage. On a dim day the intensity of light can change more quickly than the battery responds - it can get very confusing.

I would be inclined to install an in line connector in the down lead somewhere inside the van where it is easily accessible as a test point. That will also be of benefit if you ever need to reset the Sargent unit. Sargent no longer recommend removing the connector in the control panel to achieve that but advise to remove both the leisure battery and vehicle battery fuses from the PSU. If however you also have a solar panel installed you need to either disconnect or cover that before the reset can happen.

Peter

by nevergiveup Thu Nov 27, 2014 3:03 pm

I fitted a simple inline fuse holder at the back of the wardrobe to enable/disable SP. You should get 21volts or so from the SP when off load. When I first fitted our panel , we used to turn everything possible on in the van and watch the charge rate on the sargent creep up, thanks to Sunshine. Rewarding to say the least!

David

by Peterm Fri Nov 28, 2014 10:09 am

As people have said be careful drilling up through the gell coat.
My hab door lock holes have been roughly drilled from the inside by the factory leaving a big fan of nasty cracks and chips all around the lock. Of course they don't go yellow and black until the warrantee has run out, but they are a bit unsightly at the moment, and the first thing a buyer would notice.
Build Quality? AS is second to none - or next to nothing, however you look at it.

by CC Fri Nov 28, 2014 11:08 am

Well I managed to get up on the roof yesterday and unscrewed the panel and flipped it over to double check and convince myself I'd not gotten the polarity wrong and it all checked out ok...

Annoyingly I've somehow mislaid the volt meter I had, no doubt due to recently switching vans everything went into the garage and don't have a clue where it is so have ordered another cheap one off eBay and got one of the 12v socket readers similar to the one mentioned by Paul at the same time.

The 12v socket in the Broadway's kitchen area (above the sink and hob) presumably runs from the habitation battery?

What would the panel realistically generate (if at all) in these current conditions? It's very grey and overcast here currently?

by CC Fri Dec 05, 2014 4:48 pm

I've tried getting a reading from the solar panel earlier today, for a short period the sun actually shone and it was bright (for a change) The cheap voltage meter I got from eBay only came this morning, but as I've said previously I'm unclear AS to how you actually use them! As usual the instructions tell you pretty much nothing.

So could someone tell me, where do I select on the turn dial and what should I be expecting guesstimated for brightish sunny weather and / or if it's dull and overcast as it now currently is most days please?

Just a thought...

I know the mc4 connectors should ideally be soldered, but providing they are crimped on tightly and making contact they should still transfer a charge ok shouldn't they? Was tempted to join the cables in some other way and then just use heat shrink tubing to seal from the elements but thought I'd best use the proper connections.

Flicking the dial I got a reading but it doesn't make any sense to me scratch head

Solar Panel coming through roof with cable - Page 2 2untv0i

by Paulmold Fri Dec 05, 2014 4:57 pm

Assuming this is being taken at the panel before it goes to the controller, so your panel is producing 20.7v. Take a similar reading at a 12v socket and I would think it will read around 14v. In which case all is well.

by Peter Brown Fri Dec 05, 2014 5:03 pm

Well I would have guessed that brown was +ve and blue -ve and that's the way you've connected the meter. The reading shown of +20.7v is exactly what you would expect with no load connected so that side of it looks good.

The quality of the connection - resistance - only comes in to play when you start to draw current.

All looks ok so far. I would just connect back up and check the vehicle and battery voltages every couple of days for a few weeks. Once charged and maintained by the panel even at this time of year they should be 'around' 13v on the Sargent panel during the day. If either battery falls below 12.5 (and keeps falling) then more investigation into the resistance of the connectors when we get some bright days in the spring.

Peter

PS for peace of mind you could cover the panel while the meter is connected and see the voltage disappear and then reappear when the cover is removed

by Dutto Fri Dec 05, 2014 8:56 pm

Cruising Comet..................... wrote:Flicking the dial I got a reading but it doesn't make any sense to me

CC

You are really lucky .... up!

.... "flicking the dial" resulted in three consecutive "smoke with horrible smell of burning" .... tap_fingers

.... until I bought one with full instructions! allthumbz

Oh, and I still got some Dymo Tape and replaced the symbols with two little squares reading "AC" and "DC" so that I didn't forget in the future. up!

May your good fortune continue! allthumbz

Best regards,
drinksallround

by Pete Taylor Fri Dec 05, 2014 9:24 pm

The meter in the photo is set to take the hFE reading. This is the measurement of gain in a transistor and is not, as far as I can see, related at all to the voltage produced by a solar panel.

To check the DC voltage the selector needs to be turned to the appropriate DCV (Direct Current Voltage) range setting. For "normal" testing in a vehicle application this would be the 20 volts setting, however the solar panel might be chucking out more than 20v, in which case you would need to go to the next setting up, which looks like 200v. I have no knowledge of the output of solar panels, Faraday was a lad when I learned my lectrix. smile!

It would be a brave man who went near live 200v DC with a meter like this and as for the 1000v DC setting, that is for the angels. quick_run

Incidentally, the probes on your meter have exposed points, if you use it on mains voltages around the house, be careful or you could do yourself a mischief. More expensive meters have a sliding shroud over the points. 240v AC usually just gives you a fright and you let go, unless you have a pace-maker. Don't try it though!
200v DC would cause your muscles to go into spasm and you would be stuck to it until someone turned you off (almost certainly too late). These voltages are present in some industrial applications (I used to have to work on live 200v DC lift equipment) they demand the utmost respect.

If your meter instructions have not translated from Chinese too well, there are loads of pages on the web which explain how meters work.

by Paulmold Fri Dec 05, 2014 9:35 pm

I believe the pointer is set to 200vDC so what's been said above is all correct.

by Pete Taylor Sat Dec 06, 2014 12:40 am

Paulmold wrote:I believe the pointer is set to 200vDC so what's been said above is all correct.

Looks to me that it is 180 degrees from that.

by Peter Brown Sat Dec 06, 2014 7:16 am

Pete Taylor wrote:
Paulmold wrote:I believe the pointer is set to 200vDC so what's been said above is all correct.

Looks to me that it is 180 degrees from that.

To use the transistor tester and get any sort of reading you would have to have a transistor plugged into the blue socket. That along with the construction of the spline of the dial says the meter must be set to the 200vDC scale. I expect the 1000v dc setting is just to make the dial symmetrical and changes nothing.

Peter

by CC Wed Dec 10, 2014 5:50 pm

Pete Taylor wrote:The meter in the photo is set to take the hFE reading. This is the measurement of gain in a transistor and is not, as far as I can see, related at all to the voltage produced by a solar panel.

To check the DC voltage the selector needs to be turned to the appropriate DCV (Direct Current Voltage) range setting. For "normal" testing in a vehicle application this would be the 20 volts setting, however the solar panel might be chucking out more than 20v, in which case you would need to go to the next setting up, which looks like 200v. I have no knowledge of the output of solar panels, Faraday was a lad when I learned my lectrix.

Hi Pete...

No the reading wasn't taken from hFE, it was taken from DCV 20v & 200v as Paul & Peter have suggested.

What you probably can't see in the pic, is the dial has a slanted end and a triangle on the turn dial to indicate which reading setting its set to.

It's all connected up via the Sargent unit, but I'm still not certain or convinced how much juice it's actually putting into the battery, if at all scratch head

by inspiredron Wed Dec 10, 2014 7:28 pm

Unplug the panel. Switch off the mains EHU.
Calibrate the Sargent current reading following the instructions in the manual.
Reconnect the solar panel.
Read off the charging current.
You could also use the current measurement (10A DC) of your meter but that would involve making somewhat dodgy connections between one of the solar panel cable pins and its corresponding pin on the cable from the Sargent while using the meter to connect the two remaining pins. Cross connecting the pins could damage the Sargent and I could not recommend it.