Waterproof junction box
 

Hi,

Does anyone have a good suggestion for this situation.

Have four 75 watt solar panels mounted on a radar arch. Need to bring
the wiring into the boat, but only want to put two holes in the boat
(two #6 wires, positive and neg).

I want to run a pos and neg from each panel into a waterproof junction
box, where they will all be junctioned into one big pos. and neg.

My problem is I don't know of a good product (like a bus bar??) to make
the connections, and

I need the connection to be made inside a relatively small, waterproof
junction box that can be mounted on the radar arch somewhere.

I know they make this kind of product for residential electrical
applications, but I suspect there is a good alternative for marine use.

Can anyone point me in the right direction?

Mike.

You might start at the Marinco website, also check out "vaporproof"
type fixtures for commercial wiring. They are likely to be the kind of
moisture proof fixtures you need. Expensive enough without adding the
"marine" label to them.

Jonathan

beaufortnc wrote:

Hi,

Does anyone have a good suggestion for this situation.

Have four 75 watt solar panels mounted on a radar arch. Need to bring
the wiring into the boat, but only want to put two holes in the boat
(two #6 wires, positive and neg).

I want to run a pos and neg from each panel into a waterproof junction
box, where they will all be junctioned into one big pos. and neg.

My problem is I don't know of a good product (like a bus bar??) to make
the connections, and

I need the connection to be made inside a relatively small, waterproof
junction box that can be mounted on the radar arch somewhere.

I know they make this kind of product for residential electrical
applications, but I suspect there is a good alternative for marine use.

Can anyone point me in the right direction?

Mike.

have you thought about taking a plastic box, inserting a bus bar, your
wires, making sure everything works, and then encapsulating everything in
epoxy. In the 70's thats how we made "Electronic Modules"

Scott


"beaufortnc" wrote in message
oups.com...
Hi,

Does anyone have a good suggestion for this situation.

Have four 75 watt solar panels mounted on a radar arch. Need to bring
the wiring into the boat, but only want to put two holes in the boat
(two #6 wires, positive and neg).

I want to run a pos and neg from each panel into a waterproof junction
box, where they will all be junctioned into one big pos. and neg.

My problem is I don't know of a good product (like a bus bar??) to make
the connections, and

I need the connection to be made inside a relatively small, waterproof
junction box that can be mounted on the radar arch somewhere.

I know they make this kind of product for residential electrical
applications, but I suspect there is a good alternative for marine use.

Can anyone point me in the right direction?

Mike.

Mike:

I did the same thing on my boat: wired four solar panels totalling 220 watts
into a junction box on deck and then one 10 gauge cable to the DC panel.
West Marine and others sells a junction box with a phenolic base and cover.
It is about 4" x 6" x 2" deep and has a terminal strip with just enough
screw positions for 4 conductors in and 1 out, pos and neg. The cover has an
o-ring seal and there are inlet and exit grommets for the wiring. I had to
do some grinding of the inside of the cover to get enough clearance for all
of the wire and terminals. But it worked.

But you almost certainly can't fit 6 gauge wire into the box. But 10 gauge
should be sufficient. 300 watts of solar panels should put out 20 amps while
charging at 15 volts at the panels. With 10 gauge wire and say 20 feet each
way to the DC panel or wherever then the voltage drop will be only 1 volt,
giving you 14 volts at the other end. This should be enough to charge your
batteries at 20 amps.

And unless you have a mount for your panels that tracks the sun, you will
only put out the full 300 watts for a few hours each day when the sun is
near 90 degrees incidence to the panel face. FWIW a real world average is
that your 300 watts of panel capacity will put out 100 amphours of energy on
a full sunny day. So, the average current will be much less than the 20 amps
at peak.

And finally be sure to use a solar charging controller and a 30 amp fuse or
circuit breaker on the battery end of the circuit.

David

My panels have a junction box on the under/back side with terminal for both
interconnections and for isolation diodes. If yours doesn't have such a
feature, then you should also look into the need to install your isolation
diodes in your new box.

Read your panel specifications and hook up recomendations to determine if
the panels already have these panel isolation diodes installed. Redundant
diode only tend to drop the output voltage (about half amp per diode).

My thoughts and experiences FWIW.

Steve
s/v Good Intentions

Bud makes a line of heavy polycarbonate NEMA 4X boxes that have waterproof
seals and American Electrical makes a line of plastic waterproof cable
grips. Together they will seal your junctions up tight and both are
available at Digikey.com.

I am using them everywhere a critical junction might be exposed to the
elements.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"beaufortnc" wrote in message
oups.com...
Hi,

Does anyone have a good suggestion for this situation.

Have four 75 watt solar panels mounted on a radar arch. Need to bring
the wiring into the boat, but only want to put two holes in the boat
(two #6 wires, positive and neg).

I want to run a pos and neg from each panel into a waterproof junction
box, where they will all be junctioned into one big pos. and neg.

My problem is I don't know of a good product (like a bus bar??) to make
the connections, and

I need the connection to be made inside a relatively small, waterproof
junction box that can be mounted on the radar arch somewhere.

I know they make this kind of product for residential electrical
applications, but I suspect there is a good alternative for marine use.

Can anyone point me in the right direction?

Mike.

Glenn Ashmore wrote:
Bud makes a line of heavy polycarbonate NEMA 4X boxes that have waterproof
seals and American Electrical makes a line of plastic waterproof cable
grips.

You talking about Bud Radio as in Willoughby (Cleveland suburb)?

Lew

On Sun, 27 Mar 2005 05:47:10 GMT, Lew Hodgett
wrote:

Glenn Ashmore wrote:
Bud makes a line of heavy polycarbonate NEMA 4X boxes that have waterproof
seals and American Electrical makes a line of plastic waterproof cable
grips.

You talking about Bud Radio as in Willoughby (Cleveland suburb)?

Lew

==========================================

Bud Industries, Willoughby, Ohio

http://www.budind.com/cgi-bin/view?part=n4-mb

I use the polycarbonate versions:
http://www.budind.com/cgi-bin/view?part=n4x-pnr A bit better finish and
easier to work with.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Wayne.B" wrote in message
...
On Sun, 27 Mar 2005 05:47:10 GMT, Lew Hodgett
wrote:

Glenn Ashmore wrote:
Bud makes a line of heavy polycarbonate NEMA 4X boxes that have
waterproof
seals and American Electrical makes a line of plastic waterproof cable
grips.

You talking about Bud Radio as in Willoughby (Cleveland suburb)?

Lew

==========================================

Bud Industries, Willoughby, Ohio

http://www.budind.com/cgi-bin/view?part=n4-mb