"padeen" wrote in message
...
Roger, I like your parallel bilge pump idea, but I'm not sure how
you can
run this through one float switch as I've never heard of a DPST
bilge

Yup, I just realized that with a groan. There is no substitute for
sitting down and sketching out a schematic. Otherwise you end up
focusing on only part of the picture as you stand in the marine supply
store freaking out over how much it's going to cost you when the wife
sees the credit card statement.

If I weren't trying to keep battery drain parallel, I could just bring
the wires of the two pumps together at the switch which has enough
capacity for the amps. I'm using Rule's which (at least claim) to be
very tolerant of running dry. The pumps are only a foot apart anyway.

However, doing this with a pump on each battery would create a tie
between the systems which would become the main battery lead if I
turned the selector switch from both. FLASH BOOM!

So, I'll be calling the store first thing this morning and telling
them to send me another of those $40.00 switches. It's a good thing
our marina lets you stay aboard because that's where I'll probably be
sleeping this summer

--

Roger Long

No offence taken at all. I just hadn't looked for the cable sized yet
when I posted. My estimate was based on eyeballing the copper I could
see at the terminals and did not include the insulation.

The tie for the negative lead had disappeared and the yard made one up
that was about half the diameter. It's short so this is probably OK
but I need to verify that.

Oddly, I used to design electrical systems for boats but it's been
decades since I thought about them and my knowledge has leaked down to
the level of the average bear. I now design some very sophisticated
boats but someone else always worries about the electrical system. I
just write specs saying that they shall be "first class, incredible,
stupendous, and in accord with every know industry standard and
manufacturer's recommendation."

How do you like this one?

http://home.maine.rr.com/rlma/odurv2.htm

--

Roger Long



"padeen" wrote in message
...
Roger,
You'd make it easier for us, and yourself, if you could identify
those
cables with a gauge # and class, rather than a diameter. Wire
insulation
varies dramatically with its class, allowing a range of conductor
size
within a specific measurement. For instance, XLP (insulation
designation)
may be as much as .02-.05in larger than THHN.
Please don't take my post as criticism; I'm merely suggesting an
alternative
to wire descriptions by diameter.

"padeen" wrote in
news
why would the charger react badly to a normal start? This is, one
must assume, a start from a healthy battery.
Padeen


Starting means nothing. The charger simply puts out all it can during
starting, no matter how it's connected. I'm talking about leaving 20A of
load running, the lights/fans/stuff. As long as the circuit is like new,
no problem. But, this is a BOAT. Noone is going to pull apart the
electrical system and clean all the connections every 6 months. Electrical
systems on boats I meet are hard to get to, damned near impossible to pull
apart and clean. Now that 20A load is operating through BOAT connections,
all corroded from the bilge humidity, the occasional splash of seawater in
the bilge on a rough day. Ahh...those are more reality. Now, the
conveniently-connected charger is seeing a .5V drop from the battery switch
to the battery, or wherever you have the charger connected. This subtracts
from the battery's actual voltage every time someone turns on a light. So,
the charger reacts by increasing its output more than the load needs to
compensate. If it were independently connected to the battery, none of
this would matter as the charging current isn't in the path with the load
current.

Someone else mentioned their AM/FM radio buzzing. The charger connected as
you wish, not to the battery directly, will also cause any resistance in
the path to the battery to modulate the DC with charger pulses, making
electronics connected to it buzz or humm (or in the case of an alternator,
whine). This is another case for connecting the charger directly to the
battery posts, where the only way it will cause the buzz is if the battery
has a dead cell.

I'm an electronic technician. Another reason I don't like the charger
connected upstream is safety for the expensive electronics on board. If
any connection becomes loose between where the charger is connected and the
battery, the charger's full pulse voltage WILL be applied to the DC power
supply lines...18-22 volt pulses! This will destroy electronics. Unless
the battery, itself, becomes open...a directly-connected charger cannot
overvoltage the electronics. In your hookup, only one screw has to come
loose or one connection opens with corrosion and blewee!

I'm becoming convinced as well as educated. Certainly, the only place
I would connect the charger would be to the other end of big, fat,
short, battery leads. I certainly wouldn't even do that if I had
expensive electronics on board, was living aboard so that there was
significant time with DC loads being drawn while charging, or charging
via a generator.

For our simple boat however, where everything will be off 95% of the
time that it is plugged into shore power, I may still connect at the
switch. I'll see which looks most convenient when I put the charger in
and layout the leads.

The charger I bought has a standard plug. Rebuilding my rudimentary AC
panel so there is a switch for the charger is not in the cards. The
yard suggested putting an outlet box in the engine room (can a place
with no room be called a "room"). I would then have an outlet for a
light or tools as well and could disable the charger when necessary.

I'd appreciate your opinion on that Vs hardwiring.

--

Roger Long

"Roger Long" wrote in
:

I'd appreciate your opinion on that Vs hardwiring.


Boats never have enough AC outlets. There's some unwritten rule, I think.

The Amel Sharki ketch had ONE in the galley! It had been converted from
the Euro 220V outlet to 115VAC.

It now has an outlet conveniently located next to the dual battery charger
under the captain's bunk in the aft cabin....connected to two more AC
outlets conveniently located to provide AC power where there was none.

Every compartment has two or three AC outlets, now....(c;

Being able to unplug the bad charger for its return to its dealer for
replacement makes having it hard wired in a non-issue. Outlets are so easy
to install and are so handy to plug that trouble light into.....instead of
having that 50' yellow cord dragging over the decks.

Roger,
There are several good reasons to set up the battery charger as a "plug-in":
1-If you have a problem with it, the unit is easily removed for repair
or replacement.
2-Codes require a disconnect in sight of any piece of equipment and
unpluging qualifies.
3-Code requirement ends at the outlet.
I usually put a surface mount exterior plastic box local to the charger
mount and have never been disappointed.

Oh - by the by - no one out here on the sweat water (except some yard
people) take corosion lightly. It isn't as bad as it is on the coast,
but what would be a mess in a season there will take about three or fout
here. Stores still sell a lot of 8-18 to people that know. (I bet I
know whick jamoke a the marina hung the exhaust with galvanized strap.)

Matt Colie

Roger Long wrote:
I'm becoming convinced as well as educated. Certainly, the only place
I would connect the charger would be to the other end of big, fat,
short, battery leads. I certainly wouldn't even do that if I had
expensive electronics on board, was living aboard so that there was
significant time with DC loads being drawn while charging, or charging
via a generator.

For our simple boat however, where everything will be off 95% of the
time that it is plugged into shore power, I may still connect at the
switch. I'll see which looks most convenient when I put the charger in
and layout the leads.

The charger I bought has a standard plug. Rebuilding my rudimentary AC
panel so there is a switch for the charger is not in the cards. The
yard suggested putting an outlet box in the engine room (can a place
with no room be called a "room"). I would then have an outlet for a
light or tools as well and could disable the charger when necessary.

I'd appreciate your opinion on that Vs hardwiring.

"Larry W4CSC" wrote in message
...
"padeen" wrote in
news
why would the charger react badly to a normal start? This is, one
must assume, a start from a healthy battery.
Padeen


Starting means nothing. The charger simply puts out all it can during
starting, no matter how it's connected. I'm talking about leaving 20A of
load running, the lights/fans/stuff. As long as the circuit is like new,
no problem. But, this is a BOAT. Noone is going to pull apart the
electrical system and clean all the connections every 6 months.
Electrical
systems on boats I meet are hard to get to, damned near impossible to pull
apart and clean. Now that 20A load is operating through BOAT connections,
all corroded from the bilge humidity, the occasional splash of seawater in
the bilge on a rough day. Ahh...those are more reality. Now, the
conveniently-connected charger is seeing a .5V drop from the battery
switch
to the battery, or wherever you have the charger connected. This
subtracts
from the battery's actual voltage every time someone turns on a light.
So,
the charger reacts by increasing its output more than the load needs to
compensate. If it were independently connected to the battery, none of
this would matter as the charging current isn't in the path with the load
current.

Someone else mentioned their AM/FM radio buzzing. The charger connected
as
you wish, not to the battery directly, will also cause any resistance in
the path to the battery to modulate the DC with charger pulses, making
electronics connected to it buzz or humm (or in the case of an alternator,
whine). This is another case for connecting the charger directly to the
battery posts, where the only way it will cause the buzz is if the battery
has a dead cell.

I'm an electronic technician. Another reason I don't like the charger
connected upstream is safety for the expensive electronics on board. If
any connection becomes loose between where the charger is connected and
the
battery, the charger's full pulse voltage WILL be applied to the DC power
supply lines...18-22 volt pulses! This will destroy electronics. Unless
the battery, itself, becomes open...a directly-connected charger cannot
overvoltage the electronics. In your hookup, only one screw has to come
loose or one connection opens with corrosion and blewee!


This is another case for connecting the charger directly to the
battery posts, where the only way it will cause the buzz is if the battery
has a dead cell.

I wish this was true. I have new batteries and my Xantrex / Statpower 20
amp chargers are connected directly to my house and starting batteries. I
still get terrible static on my SSB and shortwave radios. Nothing on FM
fortunately so at least I can listen to music in the evenings.

Matt Colie wrote in
:

3-Code requirement ends at the outlet.


Which is why your boat isn't covered, either...

That's how they get away with that chinzy plastic AC power panel in the
wooden box, or no box at all....instead of a proper fireproof electrical
panel to keep it from burning to the waterline.

DC power isn't covered, either.

Your boat is plugged into the dock, where the code ends.....

"Gordon Wedman" wrote in
news:Rmrge.61526$tg1.47034@edtnps84:

I wish this was true. I have new batteries and my Xantrex / Statpower
20 amp chargers are connected directly to my house and starting
batteries. I still get terrible static on my SSB and shortwave
radios. Nothing on FM fortunately so at least I can listen to music
in the evenings.


This is caused by the RF radiation of the unshielded switching circuits in
the chargers.....not by them actually pulsing a good, clean battery
circuit. They radiate like hell on HF radio, a regular transmitter unto
themselves. The wiring in the plastic boat is their antenna.

You can minimize this radiation by stopping by Radio Shack and buying some
ferrite chokes for the AC and DC cables to run through. RatShack has them
in what's left of their depleted parts department. Get the square-looking
one that opens up to put the cables through and put them as close to the
charger as you can keep them. Looping one turn around them makes them work
even better.....

The best cure is if you have an old, reliable ferromagnetic or simple hand-
controlled charger....KEEP IT! They don't radiate any RF signal at all,
even at 40A of load....

Yeah, on our boat, you open up what looks like a locker while standing
in the galley with one hand in the sink and there's the bare AC
smiling at you. I gotta do something about that. Until then, the
shore power comes off before anyone steps aboard.

--

Roger Long



"Larry W4CSC" wrote in message
...
Matt Colie wrote in
:

3-Code requirement ends at the outlet.


Which is why your boat isn't covered, either...

That's how they get away with that chinzy plastic AC power panel in
the
wooden box, or no box at all....instead of a proper fireproof
electrical
panel to keep it from burning to the waterline.

DC power isn't covered, either.

Your boat is plugged into the dock, where the code ends.....