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#1

Main Message Board / Re: Shore Power Circuit Breake...

Last post by KWKloeber - Today at 03:49:43 PM

The shore power should not run straight to the bus powering the circuits.

Ok, I'm not educated on what a PO did or your particular panel (post a pic?) but, generally, the shore power cable runs to the panel main breaker, which feeds the bus that feeds the various breakers/circuits/equipment (like water heater.) 

That's "generally" - on my '84 panel for instance there's no bus; the 30a Main feeds to the Pos and Neutral terminal strips and individual fuses are wired to the Pos terminal strip. 

#2

Main Message Board / Shore Power Circuit Breaker Lo...

Last post by Tom Patterson - Today at 03:20:31 PM

We're having issues with our shore power connection and I'm trying to find the 30amp breaker that should be between the plug and the AC bus bar. I've traced the connection from the Smartplug receptacle to the panel, and I don't a see a breaker anywhere in the line. The PO replaced the original shore power connection with the Smartplug, but I can't believe he bypassed/removed the breaker. Where would the original breaker be located?

#3

Main Message Board / Re: ? Sudden overheating?

Last post by Schulcb - Today at 03:15:23 PM

Hello All,

Sorry KWKloeber, the gauge is reading those values I quoted above with the engine cover open, and continues to give erroneous (high) reading with the engine cover closed.

The wiring harness with the S wire is 12 gauge, I believe, and the temporary wire I've used to by pass the wiring harness is 14 gauge.  If the ground to the instrument panel is the culprit, wouldn't all of the gauges be giving incorrect readings?

Ron, I do have an infrared temp. gun and it consistently reads ~170 - 175'F.

Thanks,
Craig

#4

Main Message Board / Re: ? Sudden overheating?

Last post by KWKloeber - Today at 01:07:26 PM

Guys : Before you start tearing things apart - spend a few $$ on a heat detection gun and see what the temperature of the engine really is!!   

A thought

Ron

Perhaps you can post a link to your info about the engine cover grounding out the Temp switch.  I could not locate it.  Given what was explained so far that's the only explanation I see that makes any sense.

#5

Main Message Board / Re: Keel Bedding Survey

Last post by High Current - Yesterday at 08:26:16 PM

@High Anxiety

I've previously posted about my same experience re: the fingertight aft nut and keel bedding so many times that my head hurts every time I repost about it.

Well, thanks for doing it one more time.  I found your post quite helpful.  I've read a lot of posts about keels, including a few of yours, but managed to miss the similarity with the aft nut.

Are you thinking that CTY bolted-up the keel nuts/washers into wet gelcoat?  Doesn't seem logical to me.  What does, is the known issue on C-30s of torquing the nuts so many times that the washers compress the glass and bury themselves in the gelcoat.

Maybe it's not gelcoat per se, but whatever brittle white material coats the bottom of the sump partially covered all of the washers, appeared to be original, and cracked free easily when I disturbed it.  Photos below

That said I'm unsure whether I would trust the yard with anything.  Someone who blocks jack stands with 2x4s has (IMO only) questionable knowledge/conscientiousness and at worst doesn't care about their customers' yachts.  Gimmeabreak -- don't they have lumber yards in ME?

No kidding.  I have stories....

If I had time to do the work myself it wouldn't hesitate to DIY, but it's 4 hours away and I have young children who need me to pick them up from school every day.  My main reason to re-bed NOW would be to preserve integrity of the bolts.  BUT if I weren't going through this process I probably wouldn't be worrying about it...

See above for (IMO) the danger of too-often and too-tighting of the keel nuts.
Keel nuts that are 40 ft-lbs shy do not cause the Catalina smile.

Does it crush the solid glass or only the wood core that I don't have?

I used to think similarly but managed to convince myself otherwise.  Loose keel nuts put extra stress / strain on the keel-hull joint that could lead to cracks and water ingress.  On the other hand, I agree that 65 vs. 105 ft-lb is probably enough pre-load either way; at 105 ft-lb = ~10,000 lbf, a single bolt could hold the entire keel if it were in pure, static tension.

Reasons in favor of re-torquing that I can think of:
1)  Lead creep and other factors (see: corroded washer in my previous post) can reduce bolt tension over time
2)  Low bolt tension can lead to uneven loading of the keel and excessive stress/strain in the joint, possibly compromising the joint / bedding
3)  If a keel bolt has been severely corroded, I would rather have it snap off when I try to torque it on the hard than have it silently stop holding my keel.

------

(1) made me wonder:  What's the coefficient of thermal expansion of our hulls?  Does it matter at what temperature one torques the bolt?  Were my bolts loose simply because it was April?

I'm going to assume the keel stub is one inch thick (0.0254 m).

This says CTE of fiberglass is 25E-6 m/m-C: https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html  10 degC @ 1" would be 6.35E-6 m of expansion, or 0.025%.  Stainless is pretty close but let's ignore that for now to get a worst-case.

If I assume some lubrication (because anti-galling), then 105 ft-lb is about 10,000 lb of clamping force ≈ 44kN.  https://www.engineersedge.com/calculators/torque_calc.htm

The washers are 1 7/8" diameter.  Crudely, that amounts to 0.00178 m^2.  44kN / 0.00178 m^2 ≈ 25 MPa of stress.

Finally, looking here, one presumes strain is fairly linear at about 1% per 40 MPa:  https://www.researchgate.net/figure/Stress-strain-cure-for-fiberglass-Figure-6-The-stress-strain-curve-and-tyre-strip-for_fig4_305627338

Assuming I did it all right, 10C change in temperature causes 0.025% change in thickness which causes 1.8 MPa change in stress out of 25MPa total, before you consider that the stud is also contracting.  So no, temperature isn't a huge factor.  But that was fun!

#6

Main Message Board / Re: What's under the stern lad...

Last post by High Current - Yesterday at 05:19:48 PM

I can also confirm there's an embedded, threaded something on my 1990 mk1.5.  I got really nervous when I first looked under there and the studs had no nuts or washers, but I eventually put 2+2 together...

#7

Main Message Board / Re: ? Sudden overheating?

Last post by Noah - Yesterday at 03:29:51 PM

I assume Ron is suggesting using an "infrared thermometer" to measures heat, NOT a "heat gun" that creates heat. Both are good inexpensive tools to have onboard.

#8

Main Message Board / Re: New Video from Mainsail

Last post by B. Samartino - Yesterday at 03:29:33 PM

 
Wow, Great to see he is recovering so well.

#9

Main Message Board / Re: ? Sudden overheating?

Last post by Ron Hill - Yesterday at 02:51:53 PM

Guys : Before you start tearing things apart - spend a few $$ on a heat detection gun and see what the temperature of the engine really is!!   

A thought

#10

Main Message Board / Re: Oil/temp warning

Last post by KWKloeber - Yesterday at 11:20:07 AM

Edit - I've said it previously in this thread but will again. Tie down the wires so that harness movement doesn't get transmitted to the oil pressure switch terminals.  They fail too many times on the B engines. Wb doesn't put a spring-coil of wire on the sender wires to absorb vibration/movement. 
***

David where exactly where the two ends disconnected?  Were they quick-disconnect terminals?

Does she still have the black rectangular Westerbeke plugs on the harness near the back of the engine?

When did the fuel gauge stop working?

I would be rethining my choice of a mechanic if one claimed that I didn't need a harness ground wire connected!