New Electrical System Questions

[Terra Nova]

Might as well remove everything and start from scratch.

[mitiempo]

Originally Posted by Terra Nova

Might as well remove everything and start from scratch.

Agree.

[Nicholson58]

Originally Posted by SV Miss Fe

So I'm in the process of diagramming everything out for replacement and have a few questions. Great plan. You will reap the benefits forever. Otherwise, you will always wonder what is going on and when you most need to sort something out fast, you will clueless.

Once I'm confident with my diagrams I want to do use one of the deluxe panels from paneltronics. My theoretical max load (everything on at full power) is around 150 amps. Can I use a 100 amp panel since having everything on at once will never occur? I would size the panel for the max load plus some comfortable margin. Consider what you may want to add later. Also cinsider what you might get rid of or replace with more efficient stuff. How about LEDs?

Currently there are two large 12+ switch panels one forward near the mast and one aft near the battery bank. There are also multiple 3-6 switch panels spread around the boat. In my mind its a 33' boat. I'll never be far from the main panel can I just put the vast majority of switches in one large panel? Probably easier to keep the layout than to centralize unless the existing stuff is really dodgy.

Most panels seem to come with either digital or or analog meters. The boat came with a xantrex link 20 battery monitor. Can I use this and forgo the panel meters? The Xantrex will be far more accurate than analog meters. It looks like some of our originals were installed by Mr. Wizzard. All are obsoleted now with new Bogart digital meters.

Assuming I'm using high quality circuit breakers and excluding sensitive electronics do I need to use fuses anywhere? Fuses are way faster than breakers. In many cases, such as your VHF or sterio, you might install a glass Buss fuse close to the item rating. The breakers protect your wires, not the device. As a note on device protection, We have noted after a couple of lightening strikes that the devices that survived had two-pole air gap mechanical switches. This breaks both the + & - with an air gap. Most modern electronics have software switches only and get their guts blow out on a strike. I have added 2-pole switches to everything. Also on the topic of lightening, the small bow cabin wiring in our boat was sized for the tiny LED current draw. These wires were vaporized &/or fused. Stay with proper sized marine wire.

At your panel and battery cabling, use larger wire than you might think is OK. In this, bigger is better. The panel will run cooler and there will be fewer losses in your charging system.

Thank you in advance for your help! This forum is an awesome resource.

We have ignored our wiring messes until this year. Many wire ducts were packed to the top and there were 'spares' left in place for every item ever installed. I have pulled out a couple hundred feet of this so far. Fortunately, the undersized main panel wiring (known problem) was replaced by the PO. The remaining biggest mess is behind the nav station (photo) I am pulling the wires back one at a time and re-running in plastic wire ducts also being installed. This wad-O-wire is going away. There is only one main panel and this is in pretty orderly shape. Many sheets of wiring diagrams came in the boat's documents. About 95% of wires are numbered and those numbers are on the diagrams. You see two 300 AMP fuses in the center of the main power distribution. Two 500 amp shunts to the left & battery combiner top right.

[Frankly]

Not sure I understand all the shunts. I decided to group all my battery negatives together and then use a single shunt feeding my link 10.

I have included a couple of pics to give you some ideas about reducing the birds nest. I am in to building my own bus bars but they can be approximated from electrical equipment suppliers (Blue Sea).

Don't let anybody convince you that all three banks have to be physically together. As I mentioned earlier 4 midships and 2 in the fwd bilges. Under heavy charge/ discharge imbalances will happen but they all equal out when the currents get low and thus the voltage drops go to zero.

Wasn't sure about not having a starting battery (I did have a backup location if required). After 10 years I have been extremely satisfied with the simplicity of one big bank. Couple of times when I have become concerned about running the bank down, I just switch out a single set and they become the starting battery by default.

A couple of times a year I check everything out by starting from each bank singly. Always start with a cold engine with the fwd bank. Even a long way off the little 3GM Yanmar will bust right off.

Also a big believer in using terminal strips wherever major equipment connects to the electrical system (pumps, blowers, ect). Makes troubleshooting/ replacement a snap.

Consider the engine compartment a hostile environment for electrical equipment. Only put in there what is absolutely necessary.

[Frankly]

Damn, I hate this Chromebook.

[transmitterdan]

Originally Posted by Frankly

Damn, I hate this Chromebook.

Frankly,

In the second photo where there are several fuses leading away from the main DC bus there appears to be a serious fire risk due to the design. Can you spot it?

[GordMay]

#4 AWG Cu. Wire (90oC) is only rated to 90 Amps (NEC), or (105oC) 160 A (90oC) 135A (ABYC).
I see at least 1 200A fuse, and several 150A fuses. I can't read the insulation temp. ratings.

[transmitterdan]

That's a good catch but not what I was looking for.

[Frankly]

All wire is 105 degree C insulation.

ANL fuse block from bottom to top:

Main Feeed 2/0 250 amp class T at the common of the battery switch,
Fwd Battery Bank #2 150 amp, Starter #2 200 amp, Alternator #4 100 amp, IP Panel #4 50 amp, Inverter #2 100 amp, Solar #6 TBD, SSB #4 35amp

The ATO fuse block is 6 individually fused circuits with the first 5 jumped together:

20 amp Macerator, 10 amp Balmar regulator, 2amp, 2 amp, 2 amp, 1 amp all instrumentation monitoring. Feed is parallel #10 tapped from bus.

Interrupt rating of those ATO fuses is probably exceeded in this config, but can't have it all.

What am I missing?


_____________________


"My Balmar is still putting out"

[Matt Johnson]

Originally Posted by transmitterdan

That's a good catch but not what I was looking for.

Guessing the 8 gauge (maybe) wires leading to the bluesea fuse box without fuse protection.

Sent from my LG-V410 using Cruisers Sailing Forum mobile app

[ramblinrod]

Originally Posted by transmitterdan

Frankly,

In the second photo where there are several fuses leading away from the main DC bus there appears to be a serious fire risk due to the design. Can you spot it?

1. Too high current limit, exceeding wire gauge ratings (Gord).
2. Too high current limit, exceeding wire run length predicted (Rod).
3. Proximity of improperly secured wires to bottom left corner of positive buss bar without chafe protection. (Rod)
4. Don’t understand two jumpers from positive buss, but certainly lack of fuse from positive bus to Blue Sea fuse block is an issue. (Frankly)

ramblinrod
About Sheen Marine

[transmitterdan]

No, that may not be per ABYC or NEC but it isn't a problem in the real world. The fusing current of those wires is >400A.

The problem is with what appears to be a home made fiberglass terminal board. If fiberglass (or any plastic insulator) is compressed to make an electrical connection tight then the connection will surely loosen. And it will do so gradually to the point where the resistance of the connection causes heating at the bolt and then fireworks start. It is not a question of if but when.

The way to avoid that is to put a nut between the fiberglass and the terminal lugs. When tightening the connection hold the lower nut with a wrench and tighten the upper nut. This will form a good connection and does not depend on the piece of plastic to keep it tight.

[jongleur]

Originally Posted by mitiempo

A VSR (ACR) is a voltage sensitive relay. It does not charge only one battery. When the terminal post on either side of the VSR reaches a specified voltage (13.6 for 30 seconds and 13.0 for 90 seconds for the Blue Seas SI-ACR, the most common Blue Seas model in North America) it combines the batteries. After that each battery takes the current it requires, both at the same time.

I want to have
a house bank that is used for everything
including starting, and another battery used
exclusively if there is a problem with the house
bank. I went to Blue Seas's website and there
are two almost identical ACRs priced alike. I
have read their specs and neither one stands out.
Which one do I need, the SI or the Batterylink?

[Frankly]

Dan,

Good point you just don't have all the info. Output side Silicone Bronze bolt, G10, SB nut, SB flat washer, fuse blade, lug, flat washer, SB lock washer, SB nut. Don't know about getting a wrench to that bottom nut though.

The high amp fuse block is homemade but that is only because nobody had/ has chosen to produce such a beast. You could make it up from commercial components but not enough room in my case.

As to the feed for the BS fuse block, I admit to bending the rules a bit. I could have installed a say 50 amp fuse but what purpose would it serve. That fuse block is such an odd duck and I am using it in an odd fashion just didn't make sense. The total for those 6 ATO fuses is less than 40 amps and that assumes that all loads were at the fuse rating and on at the same time (none of which is true).

If some later nut comes along and loads it up with 30 amp fuses then let him swim home from the fire.

Any other legit criticism welcome.

I spend 30 years doing this for the US Navy and another 14 in the private sector, My best shot, but does not mean it is perfect.


---------------------------------

"some days you are the dog and some days you are the tree"

[jeepbluetj]

Originally Posted by jongleur

I want to have
a house bank that is used for everything
including starting, and another battery used
exclusively if there is a problem with the house
bank. I went to Blue Seas's website and there
are two almost identical ACRs priced alike. I
have read their specs and neither one stands out.
Which one do I need, the SI or the Batterylink?

Either will do. You don't need the start isolation feature of the SI and you don't need the Aux priority feature of the batterylink. Maybe one is cheaper?

I have the exact same setup you want in my Catalina 30. I have two GC6's as the main bank and a small G24 for the backup/spare battery. The ONLY purpose that the backup battery has is to start the motor if we kill the main bank. I keep the backup bank charged with a tiny trickle charger since I'm not away from shore power long enough to care. All power (in or out) is fed to wherever the 1-2 switch is.(which is always on 1 - the main bank)

Never used the spare battery yet.

The 2 gc6's fit fine under the chart table (standard battery location) and I made a new tray just in front of that under the starboard settee for the G24.