Completely seized alternator!

[KWKloeber]

Guys : Look in the Mainsheet tech notes !! 

I wrote a couple of articles one of which covers some of what Ken has mentioned.  There is a formula of how and what to set the dip switch setting at on your Teleflex engine tach instrument.  This formula compensates for a different number of stator poles and a different size pulley!!

A few thoughts

Here's an explanation taking it through the reason how the alternator construction affects the tach reading.
https://groups.io/g/Catalina30/message/112386

The Teleflex gauge troubleshooting guide that I had posed on the TechWiki site describes the switch settings to use for each type of alternator.  Other manufacturers will likely have different switch settings, so check the literature/calibration instructions (or try settings trial/error.)
       

[Sailing Amok]

Thanks for all the info and suggestions everyone. I was able to find essentially the same alternator as what I'd taken off, at a local shop. Based on the discussion here, I decided that was the logical way to go for now, with an upgrade to a larger, externally regulated alt in the near future. This one will become the backup. Interestingly, this new Mando claims 55 amps, while the old one claimed 50 amps. Other than that the only difference appears to be that they changed the tension bolt from a 1/2 inch to metric, which I only figured out after attempting to install it. Always another trip to the store! Anyway, got it installed a couple weeks ago, but due to other life issues was only able to go out for a little motor around the harbour after installation, and haven't been able to go sailing all month.
I had hoped that the weird hissing sound the engine developed over the past couple seasons was the early warning of the alternator failing, unfortunately that does not seem to be the case, as the hissing remains. I'll start a new thread about the hissing, with a video I took this week. Other than that, we're planning to head out cruising for the weekend, so fingers crossed the engine behaves, or even better, the winds behave and we don't need the engine! For a couple who are normally on the hook every weekend of the summer, this has been a rough month...

[Breakin Away]

Thanks for all the info and suggestions everyone. I was able to find essentially the same alternator as what I'd taken off, at a local shop. Based on the discussion here, I decided that was the logical way to go for now, with an upgrade to a larger, externally regulated alt in the near future. This one will become the backup. Interestingly, this new Mando claims 55 amps, while the old one claimed 50 amps...

Could you post the model number? It might be handy to know if my alternator should fail in the future. Drop-in replacements are always good to know about.

[Sailing Amok]

Could you post the model number? It might be handy to know if my alternator should fail in the future. Drop-in replacements are always good to know about.
[/quote]

It's a Wilson Reman 90-31-7001

[KWKloeber]

Excellent choice Aaron !!!

If I had to stake my life on an Alt, it would be a Wilson reman.  They are better than an OEM Mando because 100% of them are tested before they go on their shelf for sale. 
Also, Wilson can tell you the voltage set point of each so you can pick the one that has the regulator set to the closest that you want.

Wilson even sells a new SAEJ1171 (the Mando number) as WILSON 90-31-7000N.

A good place to check for Wilsons for our engines (Alts and Starters) is www.FiltersPro.com 
Tracy is a great guy and a disabled Vet.  The only thing is that you need to know exactly what you want -- it's not an "alternator shop" that has experience mixing and matching alts for oddball applications/marine engines.

[Sailing Amok]

Also, Wilson can tell you the voltage set point of each so you can pick the one that has the regulator set to the closest that you want.

Ken, I'd chosen to go that route because of your previous praise for the Wilson remans on other threads here.  I didn't realise that they could tell me the voltage set point . Are they able to tell that from the serial number? Like, would I be able to contact them with the serial number of the one I purchased and find out the set point? Obviously too late to do anything about it, but I'd be curious to know.

[KWKloeber]

, Aaron

Possibly, but in the box w/ the reman there should have been a Test Report.   Where did you buy it? 

Wilson (BBB) gave me the V set of the 4 or 5 units they had on the shelves @ different nationwide locations.
Email BBB and see if they maintain the test results in a database.

The contact I last had there who gave me the Vs was
Jerry Davis
jdavis@bbbind.com
Who knows if he's still there --- if not try the BBB webmail form
https://www.bbb-cv.com/en/contact

Here's your Alt page:
https://www.bbb-cv.com/wilson/en/90-31-7000/product/90-31-7000

Let us know!

[Sailing Amok]

Bringing this thread back from the dead. The alternator we installed last year (Wilson 90-31-7000) had worked well until this weekend. Our battery bank was more depleted than usual, but still hardly at all. According to the xantrex link we were only down 38 amp hours out of our 520. But that is still more than our usual 20ish. This was due to a fridge issue, which I'll post about in a new thread.  Anyway, once we started motoring and got up to 2000rpm, we noticed a strange smell. I sniffed around the engine room and it seemed to be coming from the alternator. According to the Xantrex the alternator was putting out 40 amps, plus whatever loads, so I'd guess 51-52 total. Pretty close to the 55 amp rating. Took a temp reading with the IR gun, and it was 128c, that's about 260 in freedom units, near the windings. I started shutting off loads and we brought the engine speed down to 1600. The amps and temp started to drop pretty quickly and the smell went away. With the Xantrex showing 30 amps, all seemed well. Question is, shouldn't the alternator have limited its output to avoid burning up? Was it actually dangerously hot, or just a weird smell because we've never had it that hot before, in which case should we have ignored it and let it burn off? This alternator has about 60 hours on it, but with our solar and everything, this is the highest it's ever run. Usually I see around 20-30 amps.

[KWKloeber]

The alt is current-limited (by its 55 amp capacity) but there is no limiting to prevent it from reaching its rated capacity because then it would not have a capacity of 55 amps.  It would be whatever the limiting was.

Investigate why/what was allowing that high a current to be produced -- somewhere there must have been a low resistance path that allowed a high current flow.  Either that or the regulator went whacky   

[robbjd]

I have a stock Mando 50 amp alternator on our M35AC. I installed a Ruuvi sensor in the engine compartment adjacent to the alternator to monitor the temperature, and my prior ignorance was bliss. I now see temps in the 140*F range while motoring and wonder if anyone has provided additional cooling/air movement in the form of fans or vents? I don't know of anyone using the engine blower for it's intended purpose, so I'm thinking of reversing the flow and running it to provide more air circulation.
Thoughts?

[Sailing Amok]

Investigate why/what was allowing that high a current to be produced -- somewhere there must have been a low resistance path that allowed a high current flow.  Either that or the regulator went whacky   

So being down only 40 amp hours,  on my house bank wouldn't be expected to produce that much of an acceptance rate eh? I thought it seemed excessive. We are having a fridge problem right now. It had a refrigerant leak, which has been repaired, now trying to get the refrigerant level to a place where it cools properly. Currently running at 7amps continuously. Maybe there's more of an electrical problem with the fridge than I presumed, and something there caused this low resistance path? Other than that, from an electrical perspective, we did install all new batteries and a new solar controller (Victron Smart MPPT) this spring.

[waughoo]

I now see temps in the 140*F range while motoring and wonder if anyone has provided additional cooling/air movement in the form of fans or vents? I don't know of anyone using the engine blower for it's intended purpose, so I'm thinking of reversing the flow and running it to provide more air circulation.
Thoughts?

I replaced my failed vinyl ducts with new fiberglass rod blue fabric-ey ones that are crush proof.  I then replaced the inline blower with a Jabsco squirrel cage blower (quieter and more cfm).  I have the fan blowing out of the engine room and the pick up for that on the port side aft right near the exhaust elbow.  The air coming out the clam shell is plenty warm when motoring so I am indeed carrying out hot air, but I plan to add an inbound blower to supply cool air near the alternator. 

[Noah]

Alex—do you have specs/model number on your "squirrel cage" blower and ducting? Some small tips on what I do:
1. I always run the blower while motoring.
2. I sometimes leave the "engine room" small door open to the head for added cooling, if my alternator is pumping out 30A-60A charging low SOC batteries.

[KWKloeber]

So being down only 40 amp hours,  on my house bank wouldn't be expected to produce that much of an acceptance rate eh? I thought it seemed excessive.

I wouldn't think so, but Alt output is controlled by the internal resistance of the batteries (PLUS any loads running at the same time as charging the bank.)  So it's not just being down 40 A-Hr, its the condition of the bank.  I had one shorted wet cell and the shore charger was boiling off acid all over the top of that battery.  it was hot as a pistol -- good thing I was aboard.

Perhaps try adding your loads back on only one at a time and see if one of them makes her jump excessively??

They are made to output 55a and not burn up -- BUT NOT 100% DUTY CYCLE!

-kk

[Sailing Amok]

We had a similar experience with our old batteries, originally installed 2015. This spring they boiled off when plugged into shore power. Likely an internal short. Installed the new bank, and it has been great on shore power, solar, and when running the engine (with this one exception) I've checked the electrolyte levels and they haven't gone down at all.

I think I may drain the batteries to a similar level, while safely at the dock, and try running the engine to see what happens. I'll slowly add loads as suggested.

It's a bit irrelevant anyway, with our AB Cold Machine out of commission, our power consumption is practically non existent. Amazing how little power the DC cooler we're using consumes. It would be nice to have the icebox functional again, but for our usual 4 day weekends, we're fine. It's only on our annual 10 day cruise that we really need more fridge space, and therefore more power.