smileypete

What sort of loads are you looking to run off 240V? Running the short term heavy 240V loads straight off a genny or Travelpower, in winter at least, should be far less problematic than running a large charger/batt bank/inverter combination. But a winter mooring with shoreline has got to be the best option.

One other thing, this topic mentions the use of stranded instead of solid cable, together with 'bootlace ferrules' necessary on fine stranded wire.

Might be nice to have some background on the boat itself, otherwise I'd assume a typical narrowboat say 55' or so. With a 32A supply it'd be possible to feed the boat with two 16A radials, maybe one for the kitchen and one for everything else. Or even a single 32A ring main, provided the loads can be distributed fairly evenly on each side of the ring - not always easy in practice. Then just add the normal 2 pole RCD, all of it will fit in a standard 4 module 'garage consumer unit' that's typically used. Unless the boat is serious money I'd fit a decent galvanic isolator with remote LED status monitor like the safeshore ones, instead of an isolation transformer, but that's personal preference. You could then have just a single selector switch between 16A, 32A, inverter. Maybe use an extra pole on the selector to isolate the calorifier and charger when the inverter is selected. On the DC side the better quality DIN sockets can be used for heavier loads alongside some car 12V sockets for small chargers etc. Maybe them fused centrally but protected by lower current DC breakers next to the sockets. If the boat IS serious money, it may be worth paying a good marine electrical specialist for an hour or two to review the design and give some tips.

What was the original reason for buying it in the first place? Selling it on for a quick profit? Apart from the word 'planar' in the title, nothing else indicated it was a genuine planar heater. If the seller wanted to get more hits on Ebay search maybe they could say '(like Planar and Eberspacher)' if Ebay allow it.

Haven't yet read all replies, but how about fit the 2 pole MCB protecting the combi into a separate small 2 or 3 module enclosure. It'd make the wiring more logical and easy to follow. Eg: https://www.screwfix.com/p/wylex-3-module-ip65-insulated-enclosure-with-visor/74436 If connecting up 'flex' (fine stranded cable) to standard leccy bits don't forget to squish some bootlace ferrules on the bare ends of the strands, as standard leccy bits generally aren't designed for fine stranded cable...

Seems like it could be time to repeat my three main scenarios for batt ownership: Plan A for most (95%?) of boaters would be decent brand leisure batts. Plan B would be Trojans but only if they can be provided with the correct charge and EQ voltages, and required maintenance and monitoring. I expect this needs a genuine long term interest, hmmm... Plan C is to use a less common battery make/type/chemistry/desulphators etc, but then you may be the guinea pig on that one. I guess relying 100% on a Smartgauge makes Plan A the best choice, and having a proper working understanding of 'tail current' opens up the possibility of Plan B? So I guess the boater's knowledge of charging and monitoring needs to match the expense and charging needs of the batts.

ISTR the DC compressor fridges have a 15A surge on 12V (according to the Danfoss data sheet) and can be very touchy about volt drop, so the cable size is ~5x what the running current will suggest. Seems the rule of thumb for 12V fridges is 1mm2 per metre distance between fridge and batts, and the info Brian posted appears to confirm that. Gotta remember that the fridge needs to start OK when there's another heavy 12V load pulling the terminal voltage down, eg big inverter.

Did it melt all along or just by a terminal. If the latter then it could be that the installer has connected fine stranded wire into standard domestic eleccy bits without a 'bootlace ferrule' on the end of the bare ends. The ferrule is needed as standard domestic eleccy bits are designed for solid core or normal stranded cable. Examples of bootlace ferrules: If it's melted all the way along it sounds like it's overloaded and needs proper diagnosis. Would help if you can post a photo of the wire in question and the stuff surrounding it.

It does sound like you'd be best off with an electrician with good boats experience or a marine electrical specialist to do the install for you. A typical simple install on a narrowboat would use a small 'garage consumer unit' with RCD and one 16A MCB feeding the whole boat. A search on 'This forum' for 'garage consumer unit' would pull up some topics, a professional install shouldn't cost the earth.

If the impeller is good maybe try opening the tap and bypassing the pressure switch, good quality external pressure switches (square D) are only about £20.

I hate hot stuffy over heated spaces, feels like I'm being suffocated. Summer is OK as I can get a nice breeze going through the boat, and ice cold drinks help.

The bit where you said 'still not a great piece of design imho' Maybe, but it's what the install instructions say...

Trust the install instructions?

Well contact them and ask if you like, then share their answer with us. I'm sure 99% of their customers, including marine electrical specialists, trust the install instructions...

I'm sure they've taken it into consideration.

According to Mr Victron it'll go down to 9.5V so 0.6V added on top is still below the min 10.5V terminal voltage for 12V batts. Maybe but Victron manufacture thousands of combis. If you can't make reliable connections, then step 1 is to find out how to make them reliably!

Victron call for 2x50mm2 and a 400A fuse so 95mm2 sounds reasonable: https://www.victronenergy.com/upload/documents/Manual - MultiPlus 3k 120V Ve.Bus enabled - rev 00 - EN.pdf No point using conduit for large conductors, cable tray would be better.

'Amps divided by three' gives a volt drop of 0.05V per metre, so half a volt for a round trip of 10 metres, or a quarter of a volt for a round trip of 5 metres. Half a volt is about 4% volt drop on 12V which is acceptable for most things, a quarter of a volt isn't too bad for a charge source on 12V, in practice that'll fall to nothing as the batts get near to full charge anyway. Sure there's probably somewhat better ways of working it out, though the cost/benefit doesn't hold up for the average narrowboater just looking to add a bit of solar...

On the above post I forgot to mention to add a suitable fuse in the controller positive cable at the battery end, the Tracer manual should cover this, or I'd go a size up on what the controller output is or what the cable can handle. So a 40A fuse for a 30A controller with 10mm2 cable. A midi fuse and holder will do and can take the ring terminals needed for 10mm2 cable.

In which case I'd follow what the Tracer manual requires, failing that do as outlined in post #11 in this topic: So nearest cable size would be 16mm2 between batts and controller for up to 40A of charge current. Then 4mm2 or 6mm2 solar panel cable between panels and controller, use the latter if using lots of panels in parallel. Sure the 16mm2 will be total overkill with a 100w panel but would allow the solar array to be extended up to 500W+. On the above topic I forgot to mention to add a suitable fuse in the controller positive cable at the battery end, the Tracer manual should cover this, or I'd go a size up on what the controller output is or what the cable can handle, so a 50A fuse for a 40A controller with 16mm2 cable. A midi fuse and holder will do and can take the ring terminals needed for 16mm2 cable.

So you have a 100w panel charging a start battery with a 40A Tracer MPPT? Seems the controller is a little oversized...

Sorry was on the mobile at work and didn't have time to say more. The forum search is a bit broken in that it defaults to searching the current topic and not the whole forum - the tech bods are unwilling or unable to fix it. Nevertheless it sounds like the pump pressure may be too low and/or as said there's a fine bleed hole in the pressure switch that can get gunked up. It s should be possible to measure the pressure with the 'tyre' valve under the black cap on top of the accumulator. Generally the accumulator pressure should be around 14psi/1 bar with pump isolated (off) and cold taps open. Then with pump powered, taps closed and pump cycled off the pressure in the accumulator should have risen to around 28psi/2 bar, this reflects the cut off pressure of the pump. Systems with a calorifier should also have an expansion vessel near the calorifier, this looks like the accumulator (in fact it's the same item used for a different purpose) and it should be pressurised to around pump cut of pressure of 28psi/2 bar with pump off and hot taps open. Systems with a 4 bar calorifier can use a higher pressure pump but even so it might be best to keep to one with a 28psi/2bar cut off pressure to reduce stress on the calorifier as they're costly if they develop a leak. A common error is buying a pump with too high a cut off pressure, but most can be adjusted down OK. Fitting a suitable pressure gauge, usually up to £10 from the likes of Ebay can make diagnosing problems much easier, they often come with a 1/4 BSP male fitting and need a BSP adaptor to get to the more useful 1/2" BSP size. If the pressures check out OK and the pump still misbehaves then one way to avoid disembowelling the pump is fit and external 'square d' type pressure switch as Tony says, cost around £20 or there's some cheaper copies from around £10, eg: https://www.ebay.co.uk/itm/Well-Water-Pump-Parts-Double-pole-Adjustable-Pressure-Control-Switch/172785420015

Trustpilot: https://uk.trustpilot.com/review/batteriesontheweb.co.uk As for the batts they're comparable to Trojans, plenty of info on their website: http://usbattery.com/ If you do use them please let us know how it went. With new batts I'd give them as full a charge as poss then record the specific gravities and acid levels, and if poss the 'resting voltage' for future reference.

What max current output is the controller? Best to follow what the manual for the equipment recommends, but a good rule of thumb for cable sizing is 'amps divided by three'. So for a 30A one then 10mm2 would allow for some future expansion, likewise a 20A then use 6mm2 similarly. Volt drop will be fine for the controller up to 5m from batts on a 24V boat. For the panels just use standard 4mm2 solar cable unless 6mm2 is about the same price in which case go for that. But the max distance (separation) you can reasonably go to keep the volt drop reasonable with 'amps divided by three' , depends on whether the system voltage 12v or 24V, and is whether the equipment is a charge source or not. Good rule of thumb here is 5m distance on a 12V boat, halve it for charge sources, and double it for 24V. For greater distances just increase the cable size pro rata. So a charge source on a 24V well halve it then double it which brings you back to 5m For a more comprehensive answer there's a few boatbuilding books around and probably a few guides out there on the web.

Could do... the foam does er expand, maybe use a bit sparingly and top up later if need be? Worth a quick look for some tips on use: https://www.google.co.uk/search?q=expanding+foam+tips