As part of understanding the onboard systems on our new boat, I've been attempting to untangle the DC main wiring
. Easier said than done! I've had a suspicion that the wiring
is not correct based on voltage and amp readings across the house vs. main battery
banks. I'm part way through the wiring and think I've found a couple of suspicious items. I would appreciate your taking a look at the wiring diagram and letting me know your thoughts.
To begin with the DC circuit includes a "West Marine Battery
Combiner". The combiner appears to be not working, as no LED activity on the unit. The other suspicious item is the previous owner left the 1,2,Both battery switch in "Both". More likely, the way the boat is wired, the house + starter batteries are in parallel and he never had a problem.
To start, here's how I think the boat is currently wired. The yellow highlighted circuits are questionable. I'll review and revise the diagram this weekend; however, I pretty confident the wiring between starter and house batteries is properly represented.
In comparing this to Nigel Calder's "Boat Owner's Mechanical and Electrical
Manual", it appears that I have both the "Relay" circuit, using the Cole Hersee SPST Solenoid joining the house and starter AND "Electronic Relay" circuit, using the West Marine
Battery Combiner across the banks. I suspect the previous owner was having problems with the Cole Hersee solenoid and not charging
the starter battery. Currently, with the "Engine Start" switch open, I measure 5.4v coming from the Cole Hersee solenoid to the "Engine Start" switch. If this isn't working, he probably added the "West Marine Battery Combiner" into the mix.
Here's what I think I need to do - would appreciate comments and suggestions.
1. Remove the West Marine Battery Combiner.
2. Remove the lead from 1,2,Both switch to Terminal Block, labeled "A".
3. Test, verify the Cole Hersee solenoid is working properly.
4. Verify Cole Hersee solenoid is tripped by oil
pressure switch and not something else.
With that, I have the alternator charging
direct to the house bank. If the engine
is running (oil pressure builds, closes oil
pressure switch), the Cole Hersee solenoid closes, allowing charge to starter battery. When starting, the Cole Hersee solenoid is open, so the starter battery runs direct to the starter motor
(regardless of 1,2,Both switch position). In addition, the starter battery is never in the DC main circuit, powering boat lights, etc.
With that, I'm not sure about the Inverter/Charger. WIth the above changes, the inverter
is only running off the starter batter (bad) and the house is never being charged. I think I then need to move Starter and the Starter Battery leads from the "Terminal Block" to the "2" position on the 1,2,Both switch. Then when on shore power
, leave the swith on "Both" This completes the charge circuit to both banks. I'm still not happy with the inverter
running from the starting battery, but don't expect to be running many 110v appliances
. I guess this would be no worse than I have today. Here's how this might look with the above changes:
Much easier to understand! A final though, the Heart 10 Inverter/Charger claims to have an echo charge for a 2nd bank. I don't know why it isn't being used. Should I use this and does this change the analysis? Should the inverter be wired into the house? To do so, this introduces a wiring problem with the length of heavy wire from the inverter to the house bank (starter batter and inverter are in stbd lazerette and house batteries are in center of boat).
I'm going to review the wiring on the boat tomorrow and update the diagrams (if necessary). As part of this, I also plan on understanding the reamining circuits. I need to make sure the battery management circuits are right and I understand how they work. I look forward to your comments.