1/BOTH/2/OFF Switches Thoughts & Musings

Joe · Jan 8, 2015

Can a dormant thread be hijacked? Or did he simply revive it? The subject was electrical.. and it was a "musing" rather than a specific question/answer post. Just curious.

Ron20324 · Jan 8, 2015

Sorry, i did not see it was a continuation. I had only clicked on from the main forum menu.

fortunare · Apr 14, 2015

wiring diagram

tkanzler said:
My Hunter 340 came wired per the butt-simple first diagram, only with two group 24 deep-cycles in parallel on #1, and it worked just fine. Ran the boat on the house batts only, and kept a group 24 start battery as the reserve, just in case. That little 3GM started with no effort, even after an all day sail across Lake Ontario using refrigeration, instruments, autohelm (intermittently), and a notebook computer on an inverter for 10 hours.

I did have a 30A, 3 circuit charger, though, with 2 of them combined for the house batts, and the other for the reserve batt., per the manufacture's instructions (again, factory, I think), so the reserve battery only got charged when I used shore power, which I tried to make a point of doing when spending any time at a dock.

Since my new (to me) Macgregor 26X has a total mess for wiring, I'm going to rewire it the same way, but add an ACR to keep the reserve battery topped up. 1/both/2/off switch again used as an on/off switch only, unless I run the house batt. down. Need to do something about a shore power charger, but with the ACR, I may only need a single output.
==============
1. What's an ACR?
2. Do you have a diagram of the circuit you ended up with? I did a search on this site and didn't find answer to fixing the mess on the 2005 Mac 26M I recently bought. Motor battery works fine but doesn't charge from the engine. House battery charges but has a maze of wires going to a switch panel and none of the interior electric or boat lights work. Whoever wired this must have been drunk. It has a 1,2 or both switch but none of the settings seem to change anything. Motor starts on 1 or both. Thanks, Mike

txg · Apr 28, 2015

Maine Sail, thanks for all your Input. I'm currently in the process of rewiring my battery bank (mainly because the boat is repowered with a new 33hp vetus engine).

Last weekend i exchanged the original 25 sq. mm (~ AWG3) wiring for 70 sq. mm (~ AWG 2/0) and added 160A battery fuses.

Batteries are two Victron 110Ah AGM for the main bank and one Victron 60Ah AGM for the reserve bank. The shunt for the bmv-602 is also installed. Next weekend, i will install the 1/2/both switch.

I will not install an ACR, as my charger has dual outputs and i plan to install two mppt solar charge regulators which are also dual output.

Bryan9 · Apr 29, 2015

Switch wiring for emergency combine

Maine Sail said:
Three ON/OFF switches...
An ON for HOUSE
An ON for ENGINE
AN BOTH for EMERGENCY COMBINE or ISOLATION

I also have a Beneteau equipped with two ON/OFF switches. Here's a helpful diagram showing how to wire the third "emergency combine" switch:

http://c34.org/bbs/index.php?action=dlattach;topic=6604.0;attach=4447;image

Stu Jackson · Apr 29, 2015

Bryan9 said:
I also have a Beneteau equipped with two ON/OFF switches. Here's a helpful diagram showing how to wire the third "emergency combine" switch:

http://c34.org/bbs/index.php?action=dlattach;topic=6604.0;attach=4447;image

Same thing, different graphics

http://c34.org/bbs/index.php/topic,6604.msg55916.html#msg55916

Bryan9 · Apr 30, 2015

Battery switch configuration with 3 ON/OFF switches

I plan to take Maine Sail's advice to use a removable key switch for the EMERGENCY/COMBINE switch, such as the following (Hella Marine Master Battery Switch):

wufibugs · May 1, 2015

At about 7 times the cost. Since it's just an on/off switch used only for emergencies it won't get much use which is a blessing and a curse. The idea would be to find one with brass lugs and contacts. I found an old automotive battery switch made before brass became so dear it had to be transported under armed guard.

SVTatia · May 10, 2015

1/both/off - Alternator question

Maine I have just installed my wiring as per your post and wired the + house battery cable directly to the alternator, with a fuse within the 7 inches from the battery and a on/off switch to work on the engine.

My questions is: Would there be a problem to the alternator internals by having a constant open power feed from the batteries? What I mean is when not in use, the alternator will be always "on". Thanks.

Bill Roosa · May 10, 2015

cars work like that all the time with no problem

Stu Jackson · May 10, 2015

SVTatia said:
Maine I have just installed my wiring as per your post and wired the + house battery cable directly to the alternator, with a fuse within the 7 inches from the battery and a on/off switch to work on the engine.

My questions is: Would there be a problem to the alternator internals by having a constant open power feed from the batteries? What I mean is when not in use, the alternator will be always "on". Thanks.

Yes, it would be, but not a problem, but MS also included the suggestion to include an "alternator service switch" to turn off when working on the engine/alternator. I simply remove the fuse when working on it. If using a switch, make sure it's closed before the engine starts.

SVTatia · May 10, 2015

Stu Jackson said:
Yes, it would be, but not a problem, but MS also included the suggestion to include an "alternator service switch" to turn off when working on the engine/alternator. I simply remove the fuse when working on it. If using a switch, make sure it's closed before the engine starts.

Thank you Bill and Stu.

S34 · Jan 3, 2016

I am in the process of wiring my boat after a complete structural rebuild and cannot believe my good fortune in finding this thread. Exactly the dilemma I am facing.
I hurriedly bought 2x 6v 232ahr batteries and what the marine shop recommended in the way of battery switch & ACR.)
(DCP & SI-ACR blueseas) in favour of my Perko 2/all/1/off and a vanilla (Auto?) relay that was part of the orig. 3gm30 install to combine batteries for charging.
After pondering the possibilities of the DCP before the install I decided to google..................Wow!

Firsty, many thanks to MS, Stu, & several others that have the patience to speak it like it is without agendas-Bravo
However comprehensive the discussion has been I have not seen the following:

If you are on bank "one" (Perko), and that bank has a melt down (short) and an emergency situation exists, how do you get to bank "two" without momentarily connecting "all" which could short "2" as well? (Without pulling fuses/connections) Install a switch on both negatives? I want to return my DCP & utilise the Perko+1 or install 3 switches.
Also, hopefully marine shop will do a deal on 2x12v instead of the current 2x6v.
All the best for 2016.

Bill Roosa · Jan 3, 2016

If bank 1 is melting down you will not incure much more risk just switching through both to off. There should not be a short down stream from the switch (or the wires would be gone for fuses blown) so you are switching through both and the good batteries see some voltage above 0 (internally shorted bats not dead yet) and into a battery internal resistance (just two cells shorted in the bat bat) so not much current is going to flow.

S34 · Jan 3, 2016

It will not rotate 360deg. so would have to be the quick pass.
Left to right facing perko /2/all/1/off/
Alternatively, I could replace with the three switch system you outlined as ideal for a Sailboat.
including the ACR.
Perko has 1099 stamp on back, Oct 1999?
Many thanks.

S34 · Jan 3, 2016

Maine Sail said:
I don't know why you would return the 6V batts in favor of a 12V house bank unless the 12V batts are truly a deep cycle product, most are not, beyond what the sticker says.

I figured if I lose a cell I no longer have a house bank, whereas if I lose a cell in 2x12V I just disconnect one battery?
The other option I thought of was to have 2x 6v deepcycle as reserve bank and switch between the two.
Permutations & combinations are mind numbing. 6v volt are Endurant R232.

Fred Villiard · Jan 3, 2016

I have had perko switches weld in the both position due to a shorted bank ad the second time due to my stupidity.
I will only use switches that DO NOT have to go thru both to switch banks.

1/BOTH/2/OFF Switches Thoughts & Musings

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