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-   -   Are my alternators redundant? (http://www.trawlerforum.com/forums/s6/my-alternators-redundant-24782.html)

djones44 02-20-2016 01:26 PM

Are my alternators redundant?
 
I have two Balmar alternators on my boat that I suspect are greatly underutilized, to the point where I'm wondering if I can remove them, if they give me any issues down the road.

I have Twin Detroit 8.2l diesels, with a new Xantrex battery charger looking after four 8D batteries and a starter battery for the 8Kw Onan generator. I will always need the generator, running often when cruising, because I have only a Princess electric stove to cook on. There is no propane on the boat outside of BBQ canisters.

Being situated on Saltspring Island, I'm already on my cruising grounds, and the new Xantrex keeps the equally new 8D's topped up to the last electron at all times. And the boat has 30A shorepower to 6 110v outlets throughout the vessel. I'm doing 75% day cruises and in summer the obligatory few weeks in the Northern Gulf Islands and Desolation Sound. No plans for Alaska or north of Port Hardy.

I'm interested in the Ryan project and hoping that I can replace the tachometer feeds from the alternators by some other means, or just manage by syncing the engines by ear as I usually do. I'm not about to remove them pre-emptively, but I can see not replacing one or both if they fail or demand BOAT units. I'd prefer to double down on maintaining the Onan instead and I like the idea of simplifying my diesel landscape.

What do you think - are they the mindless overkill I suspect they are, and vestigial to older days, or...?

djmarchand 02-20-2016 01:43 PM

Before considering letting a failed alternator just sit there not working, make sure that both sides can charge all loads if the other is out. Most boats are not set up that way. For one side, maybe just the starting battery is charged from that side.


You can fix this with rewiring and adding combiners. But Delco alternators which should fit are a pretty cheap replacement for the Balmars if you don't have heavy DC loads.


David

O C Diver 02-20-2016 03:21 PM

What's your plan if the Onan fails, go home? I have an electric stove that requires the generator or shore power. If the generator fails, plan B is the gas grill and the microwave through the inverter. No worries about my second alternator (225 amp) recharging the house bank.

Ted

ksanders 02-20-2016 03:31 PM

Quote:

Originally Posted by O C Diver (Post 416835)
What's your plan if the Onan fails, go home? I have an electric stove that requires the generator or shore power. If the generator fails, plan B is the gas grill and the microwave through the inverter. No worries about my second alternator (225 amp) recharging the house bank.

Ted

That's the way we think as well.

We have a Balmar on one of the engines that charges the house batteries.

The other engine alternator charges both engine batteries which are separated by a ACR.

We also have a on/off switch that will tie the start batteries to the house battery, in case either alternator fails.

The generator supplies a inverter/charger, and we have a backup 40 amp charger that can be activated with the flip of a switch if the inverter/charger dies.

CaptTom 02-20-2016 04:03 PM

Quote:

Originally Posted by O C Diver (Post 416835)
What's your plan if the Onan fails, go home? I have an electric stove that requires the generator or shore power. If the generator fails, plan B is the gas grill and the microwave through the inverter. No worries about my second alternator (225 amp) recharging the house bank.

Ted

I'm with Ted and Kevin. Our Princess stove doesn't get as much use as the grill and microwave (via inverter) anyway, and we'd be OK without it in a pinch.

I treat the genset starting bank as totally separate. We run the genset often enough that it keeps its own battery charged. One 100A alternator recharges the house bank. The other engine only has a 40A (I think) alternator but it only needs to keep the starting bank topped off. Switches allow this to be reversed if one fails, and a combiner can pull all three banks together if needed.

On shore or genset power, there are two chargers; one dedicated two-bank charger for the two starting banks, and the 100A inverter/charger for the house bank.

Funny story, when I bought the boat the PO had wired the combiner to keep it always closed, combining all three banks. Needless to say, one of the first jobs when I got the boat home was all new batteries and restore the combiner to proper operation.

None of this would matter for day trips, or marina hopping, where shore power recharges everything overnight. But so far it's worked great for extended cruising on the hook. We really don't need shore power; if we're not underway for 4-5 hours a day, just run the genset for an hour in the morning and evening to cook a meal, heat the water and charge up the batteries. If we're underway, and just stopping for the night, we rarely run the genset at all.

cafesport 02-20-2016 06:47 PM

Redundancy is a good thing.


Spell check via iPhone.

djones44 02-20-2016 07:52 PM

Quote:

Originally Posted by cafesport (Post 416877)
Redundancy is a good thing.

Up to a point - of course. Having twin engines, I may already protest too much.

As a designer, though, I'm not comfortable seeing three generators, the Xantrex Truecharger, an inverter et alia all soaking up salt air. And all of them with a big brother 110V grid alongside to lean on.

I guess the first thing I'd try is replacing the generator using the second engine as a PTO. (For my 37' cruiser i.e. there's no question that bigger boats need standalone generators).

Could we drop the 3rd diesel (Onan) and serve up AC from the 2nd engine,folding the Xantrex into it too as the smarts, a master alternator?

Dwight

O C Diver 02-20-2016 09:07 PM

Don't think I would want to leave the second engine running only as a generator. Not enough load for that size engine.

Ted

djones44 02-20-2016 09:53 PM

Quote:

Originally Posted by O C Diver (Post 416899)
Don't think I would want to leave the second engine running only as a generator. Not enough load for that size engine.

Ted

Good point, it's clear that we have to let the big dogs eat.

I guess I'm thinking more along the lines of twin Lehmans that are used to idling or 1000 rpm. I see the value of twins more for docking and security than speed, although 10 kn is a good thing. I guess it's cheating though; trying to avoid another diesel but running an apartment nonetheless.

To be simplistic, if we swap in a unit like this onto a Lehman, what could we do from idle (just before electrocution)?

Dwight

FlyWright 02-21-2016 12:27 AM

To your original question, "Are my dual Balmars redundant?" I'd say, yes, just like you'd want them. Is it a little overkill? Maybe, but since it's there, what's the harm? If you feel compelled to carry a cheap spare, you can get a standard 40-60A unregulated alternator.

It's nice to have that away-from-the-dock capability to recharge after a long stay on the hook. I have one Balmar on my house bank and a std unregulated 55A alt on my start battery. My Balmar really packs a punch into my house bank. I appreciate the ability to customize the charge with the external regulator.

Do you have a centerfielder managing the charge of both alts into your house/start bank? No separate start battery, right?

FF 02-21-2016 07:19 AM

Hooked up so each alt sees its own load , might save much of the recharge time.

But with a 100% noisemaker operation its moot.

Peter B 02-21-2016 07:38 AM

Quote:

Originally Posted by djones44 (Post 416818)
I have two Balmar alternators on my boat that I suspect are greatly underutilized, to the point where I'm wondering if I can remove them, if they give me any issues down the road.
What do you think - are they the mindless overkill I suspect they are, and vestigial to older days, or...?

No. They are not. Just be thankful you have them, and as one of the most trouble free items in your engine, they are unlikely to give trouble for years. As indeed others have already said in similar vein.

Better to conserve the xantrex for when the engines are not running, and save wear and tear on your generator, likewise. The price you people pay for diesel still is ridiculous, and must be one of your lowest cost items, so using both engines is a no-brainer, in my view, and those alternators are giving you virtually free power when the engines would be running anyway. You appear to have overthunk this one a mite, I think.

bayview 02-21-2016 11:57 AM

If you removed them you would have to find a shorter belt. That and interference free routing may be difficult.

Ski in NC 02-21-2016 01:23 PM

Pretty silly question. If alternator poops, just fix it. Unless totally burned up, almost all alternator trouble can be fixed at the individual part level. Balmars are just normal industrial/truck/auto alternators they hit with shiny paint.

And yes, having redundant supplies of DC power IS important.

djones44 02-21-2016 03:20 PM

Quote:

Originally Posted by Ski in NC (Post 417068)
Pretty silly question. If alternator poops, just fix it. Unless totally burned up, almost all alternator trouble can be fixed at the individual part level. Balmars are just normal industrial/truck/auto alternators they hit with shiny paint.

Alternator trouble is usually addressed by rebuilding the unit, unless you want to tear things down every time a bearing or brush goes squeaky. I change my spark plugs and my oil all at once as well.

Not for everyone to re&re&re their Balmars, and afford that as routine. There may indeed be a rebuildable one appear locally on CL, while I shop for a shorter belt or one that does AC. Run a big winch cable up to my battery switch. ;-).

I think marine instrumentation and devices will be consolidated somewhat, as PC's were, otherwise only Rube Goldberg will design boats.

Quote:

Originally Posted by Ski in NC (Post 417068)
And yes, having redundant supplies of DC power IS important.

Xantrex is Greek for redundant.

Dwight

River Cruiser 02-21-2016 08:15 PM

I for one wouldn't buy a boat without engine driven alternators. If a owner removed his alternators because he didn't want to repair them the fear of other systems he may of cannibalized would not even let me make a offer.


Sent from my iPad using Trawler Forum

Peter B 02-21-2016 10:50 PM

Quote:

Originally Posted by djones44 (Post 417089)
Xantrex is Greek for redundant.
Dwight

One small but important difference there Dwight. The Xantrex does not, repeat not, generate, it merely converts AC to DC, or the reverse. So, it's either converting AC to DC to charge, or DC to AC from batteries...

The Alternators generate charge...so not comparing apples to apples...

djones44 02-22-2016 11:10 AM

Quote:

Originally Posted by Peter B (Post 417233)
One small but important difference there Dwight. The Xantrex does not, repeat not, generate, it merely converts AC to DC, or the reverse. So, it's either converting AC to DC to charge, or DC to AC from batteries...

The Alternators generate charge...so not comparing apples to apples...

If you read the full thread, Pete, it's about whether or not I need two big expensive alternators, when I already have an 8Kw generator. I don't really want 3 diesels and more thru-hulls and exhausts in my 37 ft boat ER. A rhetorical question, of course, I will keep at least one of them.

However, to answer your point, if I actually removed both alternators and only had the Onan generator, it would feed the Xantrex and charge, repeat charge, the batteries anywhere, look Ma, no alternator(s).

Ideally I want a master 2nd Balmar that generates AC from an idling second engine. Sounds dodgy until you realize it would grant you air conditioning in Oz, without the Onan. Put that second Lehman to work.

FWIW my boat doesn't have a shower or tub, e.g. just a shower handheld that we use sitting down at my transom door behind the dinghy. The PO was handicapped and he used the whole cockpit as his shower stall. I don't lament not maintaining a shower with all its issues inside my boat. But I don't live in Florida, either, and I'd certainly need one there.

"The unexamined boat is not worth cruising."

Dwight

Ski in NC 02-22-2016 09:47 PM

What will you do if the Xantrex or Onan poops?

djones44 02-22-2016 10:35 PM

Quote:

Originally Posted by Ski in NC (Post 417577)
What will you do if the Xantrex or Onan poops?

If both alternators had been removed, I'd hope that 4 8D's at the top of their game could somehow cover my diesel ops until the next marina, if we must be rhetorical. Might not even have A/C, to really make us sweat.

OTOH, if one alternator had been swapped out for an on-engine "Balmar" that pumps sinusoidal AC to my battery switch - the Xantrex is now a chip or two inside this master alternator - which is fat-cabled to my shore power input.

If you're keeping score at home (Tinker to Evers to Chance) the Xantrex and the Onan (but not Elvis) have both already left the boat, and the second engine is idling efficiently. ;-)

Again this is scaled for small trawlers to 42 ft that require more than inverter AC but don't want another diesel.

Dwight


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