Running 230V through the bilge

[sailoppopotamus]

My no-name inverter recently broke down (smell of burning plastic on the boat ) and I'm looking to replace it. I've been toying with the idea of buying a rather oversized one (Victron Phoenix 1200VA, which will do 1000W continuous at 25 degrees) so that my girlfriend can briefly run a blow dryer on low for 5-10 minutes. Electrically I think this will be challenging, but fine, assuming a 120A draw. I have two 12V 150Ah deep-cycle AGM batteries in parallel and a dumb 80A alternator, so assuming I only get 50A out of the alternator I'm left with a 70A draw across the house bank, which hopefully won't harm it too much if sustained for less than 10 minutes. Obviously I'd have to run the engine for as long as the blow drying lasts.

One of the problems is that the current inverter, fitted very conveniently under the chart table, is physically much smaller than the proposed Victron. Not only would the new inverter annoy me in that location, it would also mean a total DC cable run of 8m (min 35mm^2) to the batteries. I've therefore been toying with the idea of installing the inverter in the stern cabin, and running a 220V cable to a socket close to the chart table. Regardless of whether the cable is 12V or 230V , the cable has to run through the engine "room" and bilges to get there. This would keep the DC cable run from the inverter to the batteries, which would also have to go through the engine room, to around 4m. Is this a foolish idea? Would it be safer to just run the DC cables to the alternator? Is the whole project of running a hair dryer off the inverter a dumb idea to begin with?

For what it's worth we typically only turn on the inverter on every once in a while to charge laptops, spare VHF radios etc.

 

[Neeves]

My no-name inverter recently broke down (smell of burning plastic on the boat ) and I'm looking to replace it. I've been toying with the idea of buying a rather oversized one (Victron Phoenix 1200VA, which will do 1000W continuous at 25 degrees) so that my girlfriend can briefly run a blow dryer on low for 5-10 minutes. Electrically I think this will be challenging, but fine, assuming a 120A draw. I have two 12V 150Ah deep-cycle AGM batteries in parallel and a dumb 80A alternator, so assuming I only get 50A out of the alternator I'm left with a 70A draw across the house bank, which hopefully won't harm it too much if sustained for less than 10 minutes. Obviously I'd have to run the engine for as long as the blow drying lasts.

One of the problems is that the current inverter, fitted very conveniently under the chart table, is physically much smaller than the proposed Victron. Not only would the new inverter annoy me in that location, it would also mean a total DC cable run of 8m (min 35mm^2) to the batteries. I've therefore been toying with the idea of installing the inverter in the stern cabin, and running a 220V cable to a socket close to the chart table. Regardless of whether the cable is 12V or 230V , the cable has to run through the engine "room" and bilges to get there. This would keep the DC cable run from the inverter to the batteries, which would also have to go through the engine room, to around 4m. Is this a foolish idea? Would it be safer to just run the DC cables to the alternator? Is the whole project of running a hair dryer off the inverter a dumb idea to begin with?

For what it's worth we typically only turn on the inverter on every once in a while to charge laptops, spare VHF radios etc.

It might be easier if you go and find a hair dryer that is not quite so powerful? You are surely in no hurry - its hardly boating weather. Xmas is coming it might part solve your 'gift' problem - kill 2 birds with one stone .

I've just noticed you are in the Med - forget part of what I posted.

Jonathan

 

[sailoppopotamus]

It's actually pretty difficult to find anything meaningfully less powerful than 800W. Nobody seems to make a 400W hair dryer, presumably because it doesn't actually go a long way towards drying hair. So I think the solution is to find a travel hair dryer rated at around 1000W and just use it on low/medium.

The whole discussion is a bit ridiculous, I agree. We live in Greece, and mainly use the boat in the summer, which only adds to the absurdity of the matter!

 

[ylop]

If a travel hairdryer on low is enough - there are some cordless hairdryers around with a battery or I think I’ve seen 12v dryers too.

does running a 1000W inverter when you have the engine running actually pull the alternator up to even 50% load or would you need to run the engine at high revs but with the only load being the alternator and if so will the engine like that?

 

[sailoppopotamus]

That is a good question. The alternator is new, and even if it weren't my batteries are primarily charged by solar so I've never needed to do serious bulk charging with an alternator before. The way I had it in my mind was that I would run the engine on idle for 2-3 minutes, then bring it up to 1500rpm and turn on the inverter & hair dryer. It's not a stock alternator so the amps/RPM curves in the Yanmar manual cannot be relied upon to guess its output. It's a 2GM20F with a single V belt -- I'm in the process of replacing the poor stock Yanmar belts with the Gates Green belts to accommodate the new alternator.

As for the battery powered hair dryers, there was only one on the market and it seems discontinued. The 12V dryers seem to be complete rubbish (based on reviews, not personal experience). They basically blow cold air, and seem to be terrible quality wise as well since the market is so small.

 

[William_H]

Back to original question. It should be no problem to run the 240v wire through engine bay not actually in bilges but in area open to bilges. I think the efficacy of running hair drier fro short period will soon become obvious. As said don't count on full output from alternator. I suspect inverter will shut down with low DC voltage fairly quickly. ol'will

 

[john_morris_uk]

I’ve run some double insulated 230 cables through the engine compartment without a single concern. Just make sure they’re clipped well and not subject to chafe.

 

[Neeves]

I’ve run some double insulated 230 cables through the engine compartment without a single concern. Just make sure they’re clipped well and not subject to chafe.

I agree.

I assume you don't actually mean running through the bilges and subject to any bilge water. The upper edges of the bilges, immediately under the cabin sole is in the bilges (but effectively along the (underside) of the sole). I secondly assume that you don't have water lapping over the cabin sole .

Jonathan

 

[Baggywrinkle]

Personally, I run all my 230v cables through the same conduit used for burrying wires in concrete. It can dip into bilges and low points as long as the open ends are well above any normal water level. Makes the cables secure and protected from impact/chaffe.

 

[ChromeDome]

Select a cable type approved for the use and make any connections waterproof to IP68 or equal.

Vanity isn't a core competence of mine, but last time I visited Greece in the summer the temperature and breeze alone made hair drying completely automatic - and fast.

You might actually get away a with blower without added heating.

 

[wingcommander]

You could mention to your partner that as a crew member a crew cut is a more sensible option....then run as fast as you can

 

[Alicatt]

If a travel hairdryer on low is enough - there are some cordless hairdryers around with a battery or I think I’ve seen 12v dryers too.

does running a 1000W inverter when you have the engine running actually pull the alternator up to even 50% load or would you need to run the engine at high revs but with the only load being the alternator and if so will the engine like that?

Yeah there are 12V hairdryers, my mother had one, she used it in the car. I have it now used it a couple of times and it works ok.
Thanks for reminding me, I'm going to dig it out to put on the boat for my wife to use

 

[RupertW]

This is something that has been nagging at me for a few years but changing the wiring would be very very difficult- not getting it out from the bilges as they are very accessible but finding somewhere else to run the 230V artic cable to the forward cabins.

 

[Boater Sam]

The absurdity is needing a hair dryer in the Med.
Running mains cable through a bilge will be fine providing it is in a conduit and well secured.
You will have to run the engine for at least 4 times as long as you think to make up for what you take out of the batteries in those few minutes, your alternator output will fall off quite quickly from its maximum, monitor it and you will be amazed.

 

[geem]

There is no problem running 230v cables through a bilge. It's far better if you can achieve it without any joints under the floorboards. They should be clipped or run in plastic conduit. My boat has had 230v cables running under in the bilge for 43 years but the cable is super high quality

 

[ChromeDome]

The absurdity is needing a hair dryer in the Med.

Yep!

See:

 

[PaulRainbow]

There is no problem running 230v cables through a bilge. It's far better if you can achieve it without any joints under the floorboards. They should be clipped or run in plastic conduit. My boat has had 230v cables running under in the bilge for 43 years but the cable is super high quality

My previous boat, built in 1980, had some original 240v wiring run through the very shallow bilge, not high quality, but domestic twin and Earth ! There was nothing visibly wrong with it, but i couldn't bring myself to leave it there and changed it for some quality cable.

 

[RupertW]

My previous boat, built in 1980, had some original 240v wiring run through the very shallow bilge, not high quality, but domestic twin and Earth ! There was nothing visibly wrong with it, but i couldn't bring myself to leave it there and changed it for some quality cable.

Can I just check what is quality cable in this instance. I ran 3 core blue outdoor cable (is that Artic?) 2.5mm through our shallow bilges. It would be very horrible trying to lead it a different way but changing it for a better cable is very doable.

 

[Graham_Wright]

My bilge cables (albeit 12 volts) run through conduits whose ends are above the presumed worst case water level.

 

[john_morris_uk]

Can I just check what is quality cable in this instance. I ran 3 core blue outdoor cable (is that Artic?) 2.5mm through our shallow bilges. It would be very horrible trying to lead it a different way but changing it for a better cable is very doable.

I use double insulated tinned copper marine cable. The only issue is that it comes in US colour coding.