Solar Panel coming through roof with cable

Just after a quick bit of info... 

As soon as we get a dry day I want to finish connecting up my solar panel, just need to bring the cable through the roof and wondering if 

1) it's best to drill from the outside in, or from the inside out? 

2) Will I need an extra long drill bit? I suspect a standard drill bit is not long enough?

When mine was fitted I know the fitter drilled from outside in. I didn't see the drill bit so can't comment on it's length.

Hi CC probably best to drill from outside in provided of course you know exactly where it is coming through on the inside. Alternatively you could drill from the inside with a smaller drill first to minimise any exterior damage. I would stick a bit of gaffa tape on the roof first.

If you drill from the inside out, then you are pretty sure it is going to come out in the right place, as in flat roof.......rather than halfway into a corner of a locker or something if you measure wrong.

Hi


Drill from the inside as DD suggests, after you have decided where you want the cable to come through.     It is only about I to 2 inches depth.


Cheers


Andy 

My fitter must have done some pretty accurate measurements because he came through just a centimetre inside the wardrobe door.

There is cabling for lights, speakers, reversing camera, heater controls and control panel between the ceiling and roof. Nobody can tell exactly where they are in any van. I've not tried a cable detector on the roof but it may work. Do though sit inside looking at the ceiling and fittings and choose a site to drill that looks likely to be free of cables. You will be drilling through GRP, insulation and boarding so (from the top) let the drill cut and don't push.

Good luck.

Peter

Thanks for the advice everyone... As Peter says my main concern was going through something I shouldn't like another cable! I'm going to be using a floor seal in the wardrobe ceiling as this is what Auto Sleepers used where they bought the TV coax from the Teleco through the ceiling and its a neat solution for the cable entry. (For the roof I have a single gland)

Surprised a standard drill bit is long enough? Are we sure about this... as I only have standard length bits and I don't want to start making holes unless I know I can fully complete the installation in one go and get everything sealed up straight away. 

Thanks 

No worries CC, I have done two now, and I have no special drills! Its that confidence bit when you start drilling.....................at least if its a small drill and you measured wrong its easier to rectify. When I did mine , SHMBO wouldnt look!! That inspired me no end.....

David

nevergiveup wrote:No worries CC, I have done two now, and I have no special drills! Its that confidence bit when you start drilling.....................at least if its a small drill and you measured wrong its easier to rectify. When I did mine , SHMBO wouldnt look!! That inspired me no end.....

David

I'm glad it's not just me worrying then.... 

Been putting it off as I can't bring myself to drilling through it unprepared, but I know I have to get the installation done so have to bite the bullet as they say  I will take your advice and put a smaller bit through first to make myself feel a little more at ease! 

Thanks All 

I routed mine down the side of the heater flue - it just needed a round file to make the shape and sealed it with caulking - no cables in the way that way 

Having drilled more than a few holes in fibre-glass bodywork (check my avatar!) I would take the advice not to push if you are drilling from the inside, use a sharp drill and let it do the work; that way you avoid bursting the gel-coat as the drill comes through. Ask me how I know about that.

Hi there,

Don't forget that there is sometimes fibrelass insulation up there and it can wrap round a drill bit!

For myself, I would start on the inside with a 4mm bit drilling just through the ceiling.  Then I would use a knitting needle to a) feel for anything between the hole and the roof and b) to push any insulation out of the way.

Before drilling up through the roof proper I would open up the ceiling hole to the desired diameter (10mm?) and double check the cavity and the path to the roof before drilling up through the roof itself.

Hope this helps.

Best regards,


PS

Don't forget to isolate all electrics inside the van before you start! 

I forgot to mention the obvious- use a hand-drill, not an electric drill.... doh.

Hi CC

It's always a bit of a teeth clenching time when drilling holes into your motorhome followed by a sense of relief when it all (hopefully) turns out OK.

I've always used something that is common to both the inside and the outside of the van as a datum point to take your positioning measurements from usually the aerial and then drilled from the outside using a small pilot drill first followed by the required size of drill or hole cutter. The old motto "measure twice cut once" applies although in my case it's "measure five or six times cut once "  being more appropriate.   

A standard drill length should suffice as the roof is only about 5 to 6 cm thick give or take a few mill' consisting of a thin outer layer usually aluminium or thin GRP then the insulation usually polystyrene on the laminated structure used these days and finally the inner board. Masking tape can be used at the point of drilling to prevent the drill bit skidding on the shiny surface.

So gird your loins and proceed with confidence.

Cheers John

Hi there,

I'm not sure that a "standard" bit will reach all the way through ceiling and roof.

From memory, in the Duetto there is quite a distance between the ceiling and the roof; sufficient for insulation and an air-gap plus the thickness of ceiling and roof I think it may even exceed 100mm.

Maybe a check on the depth of the closest skylight would give a good indication. 

Best regards,

Had to replace a roof vent on the Duetto today and thought I'd post a picture of the roof construction for you,

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Best of luck! Im sure youll be ok.My panel fitted by AS during manufacture just looks like a hole with loads of silicone crudely splodged around it! But don't forget that drill bits get shorter as they get smaller in dia so although it is really good advice to use a small dia drill ,you may have to either use a bigger dia or I would suggest you obtain a "long series" drill bit, they are not that expensive at the sizes you need                          REGARDS  Paul

Well CC?? did you do it ok??.................Don`t keep us in suspense.

nevergiveup wrote:Well CC?? did you do it ok??.................Don`t keep us in suspense.

Yes I managed to do the dastardly deed 

Actually it was surprisingly straight forward, in the Broadway's cupboard there is a round vent in the roof (which I fail to see is of any use) I fed the cable through the vent and all I had to drill through was the GRP which was fairly easy, and saved having to go through any insulation or ply etc or hitting any wires etc.

However... (There's always an however ) I'm not sure if the panel is working as I'm not getting a + readout on the Sargent Control Panel? It's been raining daily so not been able to double check everything, but hoping to look today... 

Any ideas how I can check the panel is out putting? Suspect I have to put a multi meter on the panels + & - cables first? But how do I actually use the multimeter to get the correct reading? Can I just unplug the j plug connector going into the base of the Sargent unit in the wardrobe and test there? 

Just hoping I somehow haven't mixed up the polarity of the connectors (the MC4 connectors did confuse me slightly) although I double checked everything at the time so would be surprised... If I have done this does anyone know if the onboard Sargent unit has reverse polarity protection built in for the solar feature? I know it has 'Reverse Polarity' written on the front of the unit but not sure if the solar charging bit is protected?

Thanks

CC

If the connector going into the base of the Sargent unit is easily accessible (mine is not) then pulling the plug and measuring voltage/checking polarity is easiest done there. You don't need bright sunlight but not fog, rain or drizzle. Cover the panel with a blanket or mat, remove the plug and clip your meter to the contacts (should be 0v), remove the cover and check reading then.

The best way to check performance with the panel connected is using the current drawn indication on the Sargent control panel. Perform a calibration then switch on a few lights and note the current drawn. Covering/uncovering the panel will cause a difference in the current indicated equal to that being supplied by the panel.

I got the current van new in the middle of October 2011 and had a panel installed by the dealer. Because of the poor light conditions it took me a while to convince myself and then the dealer that it wasn't working. It then took a while to find out that it was actually a problem in the Sargent PSU that was then replaced.

Peter

Thanks Peter... 

Hope it's not the Sargent PSU as I can imagine Marquis suggesting it's because of something I've done. They weren't happy when they quoted me an unbelievable price of £850 to supply and fit a 100w panel and I said I can fit one myself for around £200! The response was 'Marquis wouldn't be very happy about you fitting the panel yourself' and suggested it might affect the Marquis Automarq warranty which I thought was extremely patronising and out of order 

I have to remove the Sargent PSU in the wardrobe to access to bottom connections so think I'll check the roof connections first. I even wondered if the polarity was correct on the wiring harness supplied from Sargent as the pins didn't seem to relate to the Sargent PSU manual.

It could well be working, I just expected it to instantly be showing a + input on the control panel straight away? I did try a recalibration of the panel as the first step incase this was the issue.

CC

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.

Might try that thanks paul, have a 12v clipsal socket in the tv cupboard I could try... pretty embarrassed to admit I'm not very experienced with the use of a volt meter despite owning one however.

Nor am I, so I use one of these in a Clipsal to cig lighter converter..

http://www.ebay.co.uk/itm/Car-Vehicle-Voltmeter-Voltage-Gauge-Volt-Meter-Cigarette-Plug-Monitor-12V-24V-/261491768208?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3ce21fbb90