Electrical Upgrades

[efiste]

Thanks to the many wonderful posts on the C34 website, I think I am ready to tackle many much needed electrical upgrades on my 1987 C34. These include upgrading to 4 6V T105s, a high output externally regulated alternator, dedicated starting battery with echo charger, 1800W charger/inverter, and a battery monitor. I have procured the main components and am now zeroing in on wire, connectors, and fuses. I will be completing these upgrades in phases but in order to ensure I have the overall right approach, I have created a wiring diagram of the planned upgrades.

I have based much of my plans on the previously posted electrical upgrade details by Jim, Stu, and others. I am indebted to their generosity in sharing their information, approach, diagrams, and pictures! A few of the changes that I have made are the inclusion of a charger/inverter which (as I have read many posts about) requires very large 2/0 wire over a short distance AND a desire to keep the switch disconnects as simple as possible. I have read the many discussions about the different ways to utilize switches including the existing stock Perkins switch. I would like the primary "source" power (DC from batteries or AC from shore power) to be wired to switches on the existing Catalina AC/DC panels. I am going to replace the DC battery selector with a new Blue Sea e-series switch with has 3 positions for Off, On, and Combine (Emergency). Specifically, I want to wire all DC loads including the inverter and starting battery echo charger on this same switch. I would rather not have parallel or sub switches even though I do forgo some flexibility. I would also like to use some pre-purchased 1/0 wire and connectors for the battery interconnects but am not sure if this would be recommended with the 2/0 wire required for the inverter as a later part of the upgrades.

I have attached the document I created of my schematic. Please ignore some of my naivety in the diagram symbols. I think I pretty much used (or labeled) things correctly, but I am sure any electrical engineers would notice a few that are not correct ;-). Any help, guidance, or other thoughts would be appreciated. I think I understand the general concepts, but the devil is in the details. It will be frustrating enough to pull the 2/0 and 1/0 wire. I do not want to also set my boat on fire because of a unintentional oversight in the design.

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[mainesail]

I looked at it very breifly.

#1 No fuse needed at the alt end. Alts are "self limiting" and as cuh should not be able to "run away" or exceed the ampacity of the wire if the wire was sized right.

#2 You can't protect 2GA wire with a 300A fuse. The alternator wire needs it;s own fuse as do the "always on loads" as close to the "source" as possible. The source is the batteryr bank.

#3 The charger and echo charger wiring looks "switched". Not a good idea. You'll likely want to charge when away from the boat but you'll then need to leave the switch "ON" to do so..

[efiste]

Thanks, Mainesail. Your feedback on other discussion threads helped me get this far. In fact, you commented on my interconnect wiring in another thread. I appreciate it. Speaking of which, do you think the 1/0 wiring between my batteries in series-parallel will be sufficient with my planned install? I am trying to not waste the $60 investment in some already purchased wire and connectors, but will do so if it is not okay.

My thoughts on your feedback below:

"#1 No fuse needed at the alt end. Alts are "self limiting" and as cuh should not be able to "run away" or exceed the ampacity of the wire if the wire was sized right."

I assume you are referring to the 150 AMP MIDI fuse I have specified. I was not sure about this but would be happy to remove it for my diagram and to buy list. I guess you are saying a "short" is not really possible from the alternator if installed with the correct wire, so you do not need to fuse the wire as close as possible to the power source like other power sources. If so, I get it and will remove it.

"#2 You can't protect 2GA wire with a 300A fuse. The alternator wire needs it;s own fuse as do the "always on loads" as close to the "source" as possible. The source is the batteryr bank."

I was not attempting to protect 2GA wire with a 300A fuse but maybe that is what I have specified in my design. I assumed the alternator would not "pull" power and therefore was not an issue. If this is not the case, then I will add a 150A terminal fuse to the alternator bus bar connection. Does the 300A "main" battery terminal fuse seem appropriate for the rest of the design? I did not depict it, but will have in line fuses for any always on loads. That is just not part of my upgrades as they already exist.

"#3 The charger and echo charger wiring looks "switched". Not a good idea. You'll likely want to charge when away from the boat but you'll then need to leave the switch "ON" to do so."

This is in fact what I was trying to do. I had questions here, and I am glad you picked up on it. Is the situation of being able to charge the batteries (house from charger/inverter and starter from echo charger) that only "problem" you see? If so, I get that and think I prefer it. Or, is it a bigger problem with how the chargers might work or perform? It is the latter that I am not sure on. I thought it might even be bad that the echo charger continued to pull from the house bank even if I was away from the boat for several weeks while without shore power. I would also prefer to have a single disconnect for both the AC input (shore power) and DC input (house bank). If either is off, I know that I am not drawing current for either. Altogether it would be better to have an upgraded panel with more options, but that is for another year.

I am looking to install my system both correctly and per standards, so I will adjust if my "preferred" setup is not the best way.

Thanks again,
Eric

[Stu Jackson]

Hi, I admit to not reviewing the diagram at all...yet.  

I strongly urge you to reconsider the use of the Dual Circuit Blue Sea switch, and stick with your existing 1-2-B switch.

Why?  It's in the "Electrical 101" - Darn AGMs, which discusses the experiences of one of Maine Sail's customers, and is one of the best written stories of why the Dual Circuit concept has significant disadvantage compared to the 1-2-B switch.


AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
http://forums.catalina.sailboatowners.com/showthread.php?p=848465&highlight=darn%20agm

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These you've probably seen already, but they also discuss the practices for employing simpler switching, and do discuss the disadvantages of the DC system in somewhat great detail.

Basic Battery Wiring Diagrams  This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html [added 9/21/11]

[added 1/31/2012]  This is another very good basic primer for boat system wiring:  The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

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Yes, there are always many different ways to skin the cat, and, as Maine Sail says, the DC system is just fine for fishing boats as he describes, and explains why.

We just don't think the same system is applicable for the way we use our sailboats.

If you want separate electronics switching, to avoid potential drop outs, use the 1-2-B and a simple on/off as described.

Good luck.  No doubt more ?s later when we get a chance to dig into deeper.

Good planning always averts installation nightmares.  Great st see you've done your "homework!"  

[waterdog]

"#2 You can't protect 2GA wire with a 300A fuse. The alternator wire needs it;s own fuse as do the "always on loads" as close to the "source" as possible. The source is the batteryr bank."

I was not attempting to protect 2GA wire with a 300A fuse but maybe that is what I have specified in my design. I assumed the alternator would not "pull" power and therefore was not an issue. If this is not the case, then I will add a 150A terminal fuse to the alternator bus bar connection. Does the 300A "main" battery terminal fuse seem appropriate for the rest of the design? I did not depict it, but will have in line fuses for any always on loads. That is just not part of my upgrades as they already exist.

. Actually you would be if you eliminate he fuse near the alt.  imagine you slip with a tool around the + post on the alt.   You would then be welding in your engine compartment suppllied from the battery through he number 2 wire.   I think Mainesail is just telling you the fuse to protect that wire needs to be on the battery end rather than the alt end. 

Once you accidentally short something unfused, you develop a massive amount of respect for the energy available from the battery.  It really helps you think through the protection.  I would rather not say how I gained this knowledge...

[Stu Jackson]

Steve's right.  Fuse close to house bank (or PDP) from AO.  We also recommend a switch in the AO to house bank wire, but I have a Mega fuse and simply remove it when I work on the alternator.

[mainesail]

I think Mainesail is just telling you the fuse to protect that wire needs to be on the battery end rather than the alt end. 

Yes exactly the fuse protects the WIRE from the "source". It is not intended to protect the alternator but rather the wire so it can't short. The "source", perhaps 8000A in a short circuit event, is the battery bank. The fusing should ideally be within 7" of the battery bank. I tend to install "service switches" on alts fed directly to the house bank. This way when you are working on the engine you can turn it off. Just a simple Blue Seas ON/OFF battery switch in the engine bay marked "service switch" suffices.. Anything connected to a battery bank should be fused.

[Stu Jackson]

Eric,

Eric C34 #358

Specifically, I want to wire all DC loads including the inverter and starting battery echo charger on this same switch.

I think you may need to reevaluate this basic concept.

AC Wiring, Inverter and Path

Think of the inverter part of the I/C as a second source of AC electricity to your boat, much like the shorepower.  With your hull number, you most likely have one AC main breaker, 30 A, and maybe one or two AC sub-breakers, certainly one for the hot water heater, maybe not a second one.  That's what I have.

The combination I/Cs come with internal AUTOMATIC TRANSFER SWITCHES.  What this means is that the I/C can automatically determine when shorepower is present and use shorepower for AC power, or use the inverter for AC power if there is no shorepower present AND the inverter is turned on.  (You don't mention if you have purchased the remote control panel for the I/C, nor what brand and model of I/C you have.  Most I/Cs need the remote panel to initiate equalization charging and to control the inverter and charging functions without having to flip switches on the I/C itself.)

So, as far as AC power is concerned, and assuming you are planning to power all AC loads on the boat from the existing 30A AC main breaker on the panel with the inverter and use manual switching to turn off AC loads to avoid overloading the inverter, here's what is the simplest arrangement, and is most likely one of the many wiring diagrams in your I/C manual:

1.   AC shorepower in
2.   AC power FIRST to the I/C
3.   then from the I/C to the boat's existing AC main breaker

It's that simple:  either the shorepower feeds your main AC breaker or the Inverter does.  If that's your intent, then your diagram has it backwards.  Just switch the labels on the upper right.  AC Loads becomes incoming 30A shorepower.  Newer codes since I installed my Freedom 15 in 1999 suggest a 30A breaker between the shorepower inlet and the inverter.  This is an ADD and is not to be confused with the AC 30A main breaker in your nav station panel.

DC Charging Wiring from the I/C to the House Bank

This is where the 2/0 cables come in, because these wires are doing two things at different times.  They charge from the charger to the house bank.  They INVERT from the batteries to the inverter to the main AC breaker on your panel.  The 2/0 wires are for the large inverter loads, and are essentially waaaay oversized for the charging function.  Same wires, two different purposes, like: comin' and goin'.

These wires go nowhere near the DC switch, regardless of whether you use a 1-2-B or the DCP (dual circuit plus) switch.  The DC switch is and should be ONLY a USE switch, i.e., which battery bank do you want to use for providing DC power to the DC panel and the starter solenoid.

Since the DC loads on your boat can almost never exceed 20 A (turn EVERY light and pump and fridge on at the same time!!!)  I believe #4 wire is just fine from the banks to the switch to the DC loads, and even to the starter.  Many folks, as Maine Sail has written, have used larger wire, like #2 to #1/0, but you seem to have confused the HUGE #2/0 wire for the inverter purpose with the DC wiring from the house bank to the switch and the DC panel.

The DC side of your I/C should go to the house bank, NOT downstream of your DC switch (whatever switch you choose to use).

Echo Charge Wiring

This wiring should go between the two positive posts of your start (reserve) and house banks, NOT to an undefined "place" downstream of your switch.  I think this was mentioned before.

Summary

Suggest you "get your head around" the operation of the I/C.  I understand that you want to keep the switching simple.  This is exactly what I have done, so I do understand the concept.

If I understand your goal, then these comments should help you along.  If I missed it completely, please let me know.

PS - The basic combined I/C wiring diagram is Option 1 in the Freedom 10, 15, 20, etc. manuals available on the Xantrex website.

[efiste]

I appreciate the feedback. I have revised my schematics to incorporate much of the input including the AC side of the C/I. I was thinking that the AC circuit should be controlled from the boat panel, so that I could isolate the C/I. If I wire it like suggested (and shown in my drawing), I have to disconnect the shore power cable or switch the circuit breaker at the shore power station to interrupt power. Is this preferred over placing the C/I downstream of the boat's AC panel and then managing AC circuits on the boat via the C/I's remote control panel?

I have also added a DC disconnect dedicated to the C/I, so that I can interrupt the battery load if needed (i.e., for servicing and perhaps when leaving the boat for extended periods). BTW, the C/I is a Xantrex Freedom HF 1800.

Thanks again,
Eric

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[mainesail]

Have not really had a good look at it via my phone but you show red wires for the AC. AC wiring is:

Black = Hot
White = Neutral
Green = Earth/Ground


If your inverter is auto transfer there should be a 30A shore breaker before it that breaks both Black/Hot and White/Neutral. If you plug into a dock then you should have a fail safe galvanic isolator in the Green/Earth wire. If this unit auto transfers then the inverter feeds the AC panel and when connected to shore power it automatically transfers over to SHORE and when disconnected automatically transfers back to INVERTER. You should also have an inverter remote panel that allows you to turn off the inverter..

[Ron Volk]

Eric,

Could you let me know what program you used to do your schematic.

Thanks,

[efiste]

Maine Sail,

Thanks. I realize it is probably difficult to fully look over on a phone. Thanks for what you could provide. I knew about the galvanic isolator but forgot to include it. Should it be located before the AC breaker (on the boat) or after? Regarding the "shore power" breaker, do you mean that I should switch my AC Loads and Shore Power leads (i.e., place the C/I after the main boat AC selector) in my diagram or something else? I have updated the diagram with what I think you are referring to.

Eric

[efiste]

Sorry, I just re-read Stu's post from back in early May and see that he made it clear that I should have the shore power AC go directly to the C/I (as pictured before and now again) with a 30 AMP breaker in between and then feed the existing AC panel. I will update the diagram again and re-post. Thanks for everyone's continued help.

Eric

[efiste]

Eric,

Could you let me know what program you used to do your schematic.

Thanks,

Ron,

I am just using MS Visio from my work PC. Not quite all the right symbols, but something usable for discussion and to follow later.

Eric

[efiste]

Sorry, I just re-read Stu's post from back in early May and see that he made it clear that I should have the shore power AC go directly to the C/I (as pictured before and now again) with a 30 AMP breaker in between and then feed the existing AC panel. I will update the diagram again and re-post. Thanks for everyone's continued help.

Eric

Here's my update schematic which hopefully incorporates the correct updates from all of the helpful feedback. If this is right, the only thing I have left to buy is the new 30 AMP AC breaker and find room on my limited panel space. I also need to figure out how to build a base for the starter battery to be located in the aft cabin along the lines of what has been posted elsewhere on this site. Thanks.