Hot Foot in the Engine Room

[Capt Phil]

For those of you who have had to change out batteries in hot weather in an engine room, this might save you some pain and embarrassment. It was time to remove the old 8D's from our house banks and replace them with a new set. We had a 32 volt system for our house bank which required 4 batteries to be swapped in each bank. Naturally, they were located in the most awkward spot having to lean over the CAT D330 engines to remove and set each battery into the box on the outboard side against the hull. After unhooking the electrical lines from the battery terminals to the isolator switch, the plan progressed to the point where we had dropped each battery into place and were about to hook up the electrical lines to the battery terminals again. I had first hooked each battery together in series and holding the last positive lead in one hand, I placed it onto the positive battery terminal and was thrown across the engine room into the gen set! I had neglected to realize that I was standing barefoot on the broad copper sheeting that was the counter balance for the SSB radio transmitter! Even experienced cruisers make dumb mistakes!! Hope this helps someone ( or at least gives them a laugh).

[GordMay]

Thanks for sharing that cautionary tale.

How does one wire a 32 volt battery system?

[sailingmonica]

Ready to learn something new....

[anjou]

12v and 24v wont mathamatically divide into 32v

Amperage is more dangerous than voltage if your well grounded.

[S/V_Surya]

What is so hard you just take 21.3 1.5 AA batteries. Sheesh !!!!

[nigel1]

Originally Posted by GordMay

Thanks for sharing that cautionary tale.

How does one wire a 32 volt battery system?

I'm guessing at 4 x 8V Batteries

[Philsboat]

I was helping a friend change the oil on his brother's Norseman 447 when my friend let out a yell.He burned his back when he leaned against a bulkhead.We pulled back the insulation and found the bulkhead was charcoal all around his house battery isloation switch.The loose connection on the switch was red hot and ready to set the boat on fire .All it needed was some oxygen and a bit more time.
We then went over all the other high current connections on the boat.Kind of scary as we were in Dubrovnik getting ready to head for Italy.
Fires at sea aren't much fun!

Phil

[Capt Phil]

Nigel1 has it right. Each bank generates 32 volts, there are 4 8D's in each bank. This was standard voltage on house banks back in the 40's, 50's and into the 60's particularly on smaller commercial vessels. They were usually coupled with a standard 24 volt starting system so in a pinch if you lost your starting bank, you could jerry rig 3 of your 8 D's together to kick over the engine(s). You had to be careful of the amperage though otherwise you could fry your starter.

[Blue Stocking]

Never saw an 8D that wasn't 12volts. I used to drive Mack fire trucks that started on 32v, but that was thru a series/parallel switch for starting.
How does that 'rithmatic work.

[Capt Phil]

I didn't know Mack trucks had 32 volt starting systems... These 8 volt batteries are not all that common any more but were available a few years ago in San Diego. They were pretty spendy as I recall but a lot cheaper than re-wiring the whole boat which was a 1974 DeFever 54 with twin CAT's in her. My 32 volt banks were in series as I recall. 'Gave me quite a jolt in my bare feet!

[GordMay]

Thanks.
I’m embarrassed to have been unaware:
T 875 ➥ Trojan Battery Company

[svcambria]

Rolls 8 volt, Sections F,G, and H

Specifications - Marine | Rolls Battery

or 16 two volt batteries (Section A)?

Michael

[VirtualVagabond]

Originally Posted by GordMay

Thanks for sharing that cautionary tale.

How does one wire a 32 volt battery system?

...with Capt Phil's little instruction manual, and maybe thick rubber soles

[capn_billl]

It's easy to forget because 12volts wont do more than a slight tingle. But put a few in series and they can push enough current to hurt. I always wear shoes in the engine room. Mostly so I don't step on a screw or something. I have shocked myself enough to feel it when resting a sweaty elbow against the engine while connecting the house bank. 50 volts and above is considered hazardous with DRY SKIN. Any moisture and the skins resistance drops WAY down. A phone lineman was killed with 24Volts he was working on during a rainy day. Be carefull, remove ALL metal jewelry, better wear gloves when working on live power of any kind.