electrician says vhf should go straight to battery

[prv]

VHF straight to battery - always. How else do you call for help if the electrics fail? Except flattening the battery of course.

What other kind of failure did you have in mind? All I can think of is a connection coming off a switch terminal or busbar behind the panel, which is a) unlikely with reasonable maintenance and b) trivial to fix. I guess the wire itself could chafe through somewhere out of sight, but your direct connection is susceptible to that too (and in your case it can't be turned off when it starts sparking, and is live and ready to cause damage even when the boat's unattended).

In any case, I wouldn't expect to be calling for help for an electrical failure (including flat batteries which is hardest to solve) unless I had an urgent need for the engine and was unable to hand-start it (I haven't tried that yet so don't know if it's feasible).

Also, as the prime mans of distress calling it should always be immediately available to any user who does not know the boat.

If I've fallen off the boat underway the radio will already be on. If I've suddenly been struck down by galloping gingivitis or whatever at anchor then 999 on a mobile is probably as good as anything, assuming I've inadvertently taken aboard someone who can't identify a clearly-labelled "Radio" switch on a panel right in front of their nose. I can't help thinking that applying power is likely to be the least of the worries of someone who's never operated a VHF before.

KS's VHF is and will remain connected via the switch panel. Switch panels are not some complex and mysterious beast liable to fail at any moment. Do you all run your nav lights direct from the battery too?

Pete
PS: A separate battery for the VHF, on the other hand, is a good idea if you can manage it. I consider it overkill for KS.

 

[Heckler]

I've never had an electric bilge pump, nor wanted one.

Hee hee, me neither! No water in my bilges, dry as a bone. If Beneteau thought them necessary they would fit them!
Stu

 

[vyv_cox]

Who would have thought that such an innocent question would run to 43 posts?

 

[TradewindSailor]

As coding only applies to vessels used commercially...... The quote is taken from the standards that would apply to a charter yacht.

I did not say it specifically requires direct wiring as the requirement is about function and not means of achieving it. Difficult to see how the requirement could be met without an independent supply.

Read BoatMikes contribution carefully, I don't think I can do better :

"Having fitted out many ferries and commercial vessels needing Lloyds and MCA certification I think the definition of the subject under discussion needs to be clarified. For “straight to the battery” please read “straight to the battery isolating switch” No battery should have wiring direct to it without the facility to isolate the battery and isolating switches should always be as near to the battery as possible. The requirement to wire VHF radio and indeed other safety related items direct rather than through a general service panel is to ensure that a short circuit or failure in the domestic circuits does not interfere with the “safety” circuits. Fire is not the only issue. Flooding, or other damage may also require that all other circuits are isolated ASAP. In the case of ferries the usual preference is for a separate battery for safety related supplies that is not in the machinery space. The normal requirement however is for a supply independent of other general house supplies. For small yachts like ours it is sensible to apply the principle as far as possible. This may mean taking the VHF from the battery isolating switch or indeed the feed in to the main service panel. Obviously the first is preferable, but if, like my boat, the battery bank is some way away from the VHF and distribution panel and there is a very large heavy cable feeding the latter, it is in my opinion acceptable to use that same feed and connect to the input terminal to avoid the need for a duplicate heavy cable to avoid voltage drop. Either way the issue of bilge pumps is an “owner issue” frankly there is nothing in the code to say you should leave a feed to these when the ship is docked and passengers disembarked as there is no MCA related safety issue when the passengers are ashore. Under no circumstances however should anything at all be wired directly to a battery terminal without the facility to switch it out of circuit before connecting or disconnecting batteries.
"

There is a very serious point behind this : The Tread Starter stated that an electrician required that the "vhf should go straight to battery".

My position is that it is not required by any legislation, even for commercial boats.

My view is similar to BoatMike's that no system should be left permanently connected to the batteries .... except perhaps for the bilge pumps. By running small guage wires back to the battery, usually in the same conduit as the heavy guage (sometimes 150 amp fused) supply cables can be a recipe for electrical fires. Consider a local fire, chemical leak, or biological infestation, that causes the breakdown of insulation between the 150 amp +ve cable and the light 5amp negative. Unless that negative is also fused for 5amp (rare in my experience) you will have a glowing red hot cable running all the way back to the battery bank; not only melting the other cables in the conduit, but also causing acrid smoke and starting fires.

Remember that there are a lot of boats out there with different battery / vhf arrangements. It may require a 40 or 50 ft cable run to attach a vhf directly to a battery, rather than attach it to a well designed and protected supply point.

In addition for both commercial and non-commercial boats, the vhf should be switched off while the boat is unattended ...... all those DSC alarms going off with nobody onboard .... urgh!

 

[fisherman]

When I got my boat it had only one bank of batteries, in the engine room. I quickly changed to a dual system, with the service batteries above deck. Hopefully in a flooding or fire below situation there is a good chance the VHF will function.
You could, I suppose, have a VHF dedicated battery, (£50 from Halfords?) as close to the set as possible, with a heavy cable from the main system, with an isolation switch. You need the cable heavy to cope if the VHF battery is flat. Switch on with everything else, battery gets charged, but you can isolate instantly if required. Probably need a diode as well, not to discharge the VHF battery back to the main system when not motoring.

 

[H2O2]

Don't jeopardize your connection

electrician says vhf should go straight to battery but i think i should wire it to the blue sea breaker panel what do you guys think ?

A working VHF could be your very last life line. Dont jeopardize this by having it wired over a fuse or a breaker.

 

[sjclewes]

Thanks everybody, what an unbelievable response it has made very informative reading and I’m now clear in my mind where I’m heading. It never ceases to amaze me how brilliant this site is, when one has a dilemma there are always so many kind and helpful people out there ready to help. All I can say is a great thanks to you all.

 

[TradewindSailor]

a working vhf could be your very last life line. Dont jeopardize this by having it wired over a fuse or a breaker.

this has to be the most stupid and dangerous suggestion i have seen for a long time!!!

 

[oldharry]

What other kind of failure did you have in mind? All I can think of is a connection coming off a switch terminal or busbar behind the panel, which is a) unlikely with reasonable maintenance and b) trivial to fix. I guess the wire itself could chafe through somewhere out of sight, but your direct connection is susceptible to that too (and in your case it can't be turned off when it starts sparking, and is live and ready to cause damage even when the boat's unattended).

In any case, I wouldn't expect to be calling for help for an electrical failure (including flat batteries which is hardest to solve) unless I had an urgent need for the engine and was unable to hand-start it (I haven't tried that yet so don't know if it's feasible).



If I've fallen off the boat underway the radio will already be on. If I've suddenly been struck down by galloping gingivitis or whatever at anchor then 999 on a mobile is probably as good as anything, assuming I've inadvertently taken aboard someone who can't identify a clearly-labelled "Radio" switch on a panel right in front of their nose. I can't help thinking that applying power is likely to be the least of the worries of someone who's never operated a VHF before.

KS's VHF is and will remain connected via the switch panel. Switch panels are not some complex and mysterious beast liable to fail at any moment. Do you all run your nav lights direct from the battery too?

Pete
PS: A separate battery for the VHF, on the other hand, is a good idea if you can manage it. I consider it overkill for KS.

Nothing like this has ever happened to me in 40 years sailing either. But I prefer to have the radio ready without having to grope round for a switch in the dark at 3.00am with the boat rapidly making water, in a F10.

And if I have fallen off the boat, being usually single handed I am very unlikely to be back to tell you about it, whether or not the radio was on.

I just think its safer to have my radio working independently of everything else, and I dont have room for a dedicated battery for it. But then perhaps thats a throwback to the early days of wooden MAB's where the electrics were by definition something less than reliable anyway! Electrics in the older 60s plywood boats that I grew up with were like their Stuart Turner engines - worked when they felt like it!

 

[lenseman]

A working VHF could be your very last life line. Dont jeopardize this by having it wired over a fuse or a breaker.

Hello H2O2 - Welcome to the forum

Please can you fill in your bio a bit more as I would like to mark my charts so that I will know which parts of the ocean to steer clear.

What you have suggested is a very silly indeed, as a fire on a boat is probably one of the most dangerous things that can happen whilst afloat and any un-fused electrical circuits are as silly as smoking or using matches whilst filling a petrol tank!

 

[prv]

I just think its safer to have my radio working independently of everything else, and I dont have room for a dedicated battery for it. But then perhaps thats a throwback to the early days of wooden MAB's where the electrics were by definition something less than reliable anyway

I think that's exactly what it is. When people were first fitting electricity in yachts it would have been a somewhat suspicious thing, and you'd want all kinds of shutoffs and backups in case some undefined disaster befell it. Much of this was then passed down as "essential" without thinking too hard about it. How many of us have "battery isolator switches" on our cars, for instance?

Pete

 

[Ubergeekian]

I think that's exactly what it is. When people were first fitting electricity in yachts it would have been a somewhat suspicious thing, and you'd want all kinds of shutoffs and backups in case some undefined disaster befell it. Much of this was then passed down as "essential" without thinking too hard about it. How many of us have "battery isolator switches" on our cars, for instance?

Loads of people with classics. I use one of these on my Herald

Triumph, bless 'em, only fused the headlamp flasher circuit and nothing else, so this is my way of minimising the chance of a hungry mouse setting fire to several years of work. All cars used for rallying - which doesn't necessarily mean rally cars - have battery cutoffs too, I believe.

 

[prv]

I use one of these on my Herald

There's a coincidence - I was just googling such things as I was thinking of fitting them to KS to fill the isolation role of the big chunky 1-2-both-off switch when I replace its charge-directing role with something more sophisticated.

All cars used for rallying - which doesn't necessarily mean rally cars - have battery cutoffs too, I believe.

That's not exactly the norm though, is it?

Pete

 

[Tranona]

"

There is a very serious point behind this : The Tread Starter stated that an electrician required that the "vhf should go straight to battery".

My position is that it is not required by any legislation, even for commercial boats.

Sorry you chose to read "direct to the battery" as meaning unfused and unswitched. I used the term "independent supply" - that is independent of the main distribution panel.

The requirement (as in the MCA document) is for a secure supply and all I was suggesting is that this is met by an indpendent supply - and I am pretty sure that is what the OPs advisor was saying.

You are just confusing function with means as there are different ways in which this requirement can be met - on my boat it is a completely independent dedicated battery, but that is what the Greek surveyor required in line with their coding requirements.

 

[Ubergeekian]

There's a coincidence - I was just googling such things as I was thinking of fitting them to KS to fill the isolation role of the big chunky 1-2-both-off switch when I replace its charge-directing role with something more sophisticated.

It seems to work pretty well, and it's well made too.

That's not exactly the norm though, is it?

No, but battery isolators are common on cars which are left unattended for long periods (classics) or which are more likely to take up unusual attitudes (rallying) and both of these are fairly close parallels to boats ...