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Gene Neill · 30-11-2019, 06:12

Quote:

Originally Posted by DanaTucker

I am a big fan of being able to turn off main circuits using one switch. If I am sailing, the starter and shore power circuits are always switched off.

Quote:

Originally Posted by smac999

you should have a seperate swtich for the engine starter and house panel. 99% of the time the engine switch can be off, but the house switch can still be on. you want to be able to power one and not the other.

So the consensus is, I should have another on/off switch for the engine control panel? It would make sense to have no power going to the engine when no power is needed, which is the vast majority of the time.

I had thought the ignition switch itself would be sufficient ...

Gene Neill · 30-11-2019, 06:35

Working on it ...

DanaTucker · 30-11-2019, 07:19

Quote:

Originally Posted by Gene Neill

So the consensus is, I should have another on/off switch for the engine control panel? It would make sense to have no power going to the engine when no power is needed, which is the vast majority of the time. I had thought the ignition switch itself would be sufficient ...

In most cases it would be. Way back when, I had a helper that needed to charge his phone using my truck. He did not know the USB ports were wired directly into the battery. He turned the key to the accessory position, which allowed power to the ship to shore radio, cd player and dash gauges. Ten hours later, soaking wet, tired and starving, I went to start the truck and all I heard was click, click, click. We were the last ones on the job.

It is hard to figure out all the things that could go wrong when you have no one else to rely on or being out of radio range. Another good thing about the main motor battery switch is even though your ignition is off, you still have a main power source going to the starter as well as the alternator.

It is easy to be working around the motor and cause a short or create a spark, if you come into contact with either power point with metal tools. Like all things dealing with boating, it is always better to spend a few extra dollars if you can, to avoid the 1,367,456,890 things ya never though would happen to you.

Spot · 30-11-2019, 07:34

Gene, I would not swap the starter pic for the panel as the panel key switch is controlling the solenoid that controls the starter.
This is an interesting diagramming method. For me personally I would want all wires included, including the engine subsystems like temp, oil pressure, glow plugs, etc...

CatNewBee · 30-11-2019, 08:47

Quote:

Originally Posted by Gene Neill

Working on it ...

The victron BMV shunt has also a positive wre with a fuse to the battery pole.

roland stockham · 30-11-2019, 09:18

My 2c worth.

I prefer at least one bilge pump to be hard wired in with just a fuse at the battery end (for fire prevention). I have found the little 3 way switch panels to be unreliable. I would also fit a min of two pumps.
Why fit a swich on the alternator feed. If it ever got turned off wthe the motor running it would blow all the alternator diodes. If you need to turn off the altanator the switch should be in the field curcuit.

Where is the start battery?

You appear to be running the starter from the house bank. To me this is dangerous on any open water boat. It is also likely to damage the batteries as house banks are not designed for high currents. Maybe this is just left out on the diagram?

Stu Jackson · 30-11-2019, 10:07

Quote:

Originally Posted by Spot

Gene, I would not swap the starter pic for the panel as the panel key switch is controlling the solenoid that controls the starter.
This is an interesting diagramming method. For me personally I would want all wires included, including the engine subsystems like temp, oil pressure, glow plugs, etc...

Spot on! pun intended!!!

waterman46 · 30-11-2019, 12:44

Quote:

Originally Posted by Red Sky

I don’t get the on/off switch before the starter, it’s not the starter switch??? Wouldn’t there be a fuse and on/off switch from the house bank, after the bilge pump connection but before the + strip?

Following comments are based on your original diagram. It was good enough for a very simple system, with caveats.

Your On=Off switch is the battery disconnect switch. It is placed correctly. Yes some will want you to add a starter battery (I would also) but I assume you didn't want to do so, and that is OK for a very simple system but far from ideal.

I assume you are just not showing the starter solenoid and starter button circuit, but they must be present if you want to start the motor!

Yes you can remove that switch to the alternator. In place of that switch you can put a 100A circuit breaker. I did that on mine. It functions as a switch also, but importantly will protect the battery if there is a short in the alternator.

Finally, your bilge pump really should have separate manual and water level switched circuits. Can't see from your diagram what is actually there, but basically there can be two +12V wires to the pump. One circuit, switched from the main panel and labeled "Auto Bilge Pump", feeds power to the bilge water level switch and hence to the pump. You would leave the main battery switch and this Auto Bilge Pump switch ON when you leave the boat. A second circuit for the bilge pump +, switched from the cockpit if possible or anywhere else it is convenient, gets fused 12V directly from the battery switch and is labeled "Manual Bilge Pump". So the manual circuit bypasses the main panel and the bilge level switch. The pump ground remains the same as you have shown.

Montanan · 30-11-2019, 13:29

First thoughts and just a brief read of the posts.

Question: What are the two device shown in series before the bilge pump? That circuit does not have a fuse / breaker protection, nor do they have any switch controls.

You have indicated a 300 amp fuse linked to a 2/0 gauge wire. Either the wire is undersized or the fuse is oversized considerably. Revisit that portion.

You have a 225 amp fuse linked to a 75 amp alternator. Reduce that fuse clearly overkill for the power it is intended to provide protection. The 1/0 conductor seems oversized but as always depends on the length of run and if oversized for the voltage drop specification of the round trip circuit no real harm done.

Will a 2 gauge conductor handle the cumulative load applied to your DC panel?

**Wotname** · 30-11-2019, 14:01

Quote:

Originally Posted by Montanan

First thoughts and just a brief read of the posts.

Question: What are the two device shown in series before the bilge pump? That circuit does not have a fuse / breaker protection, nor do they have any switch controls.
...........

One device is an in-line fuse and the other is the bilge pump switch/control panel panel!

**s/v Jedi** · 30-11-2019, 14:15

Your latest diagram is really wrong. The engine control panel does not have any load carrying starter wires.

Sorry but you are too unfamiliar with electrical circuits to be modifying schematics. I recommend you stick to RC’s original schematic as that is correct.

Montanan · 30-11-2019, 14:15

Quote:

Originally Posted by Wotname

One device is an in-line fuse and the other is the bilge pump switch/control panel panel!

smac999 · 30-11-2019, 18:54

Quote:

Originally Posted by Montanan

You have indicated a 300 amp fuse linked to a 2/0 gauge wire. Either the wire is undersized or the fuse is oversized considerably. Revisit that portion.

300a fuse on 2/0 is totally normal. every 2000w inverter is wired that way.

Montanan · 01-12-2019, 09:02

Quote:

Originally Posted by smac999

300a fuse on 2/0 is totally normal. every 2000w inverter is wired that way.

No inverter is depicted in the OP circuit diagram, only a DC switch panel. I asked the OP what the specified cumulative load of the DC panel is so as to ascertain the appropriate conductor sizing which in the circuit drawing is depicted as a 2 gauge. The DC panel has an inline fuse depicted, but does not indicate the amperage rating thereof.

The ampacity rating of a 2/0 wire is much less than 300. It would be inappropriate to utilize a fuse that exceeds the conductors or the anticipated load ratings.

Specialized fuses utilized with inverters commonly have a blow rating twice that of the continuous rating so as to accommodate the short period of surge power requirements for appliance start ups.

It would be inappropriate to have a 300 ampere continuous rating fuse in line with a 2000 watt inverter.