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Somebody help Capt. John

 

Ill try to make this a short read, LOL Impossible.
Found this older Sail Craft in St. Pete Florida, discovered its has three phase PM servo motors, 2000 watts of solar, regen, 2 ac units, no genset, and a 240v charger, uses 12 group 31 AGMs, all below floors in each hull, twin systems with cross tie for charging both sides at the same time. 8 more AGMs for two 12v house systems, 3 inverters. older style catamaran @ 44 LOA and 20 Beam.? Apache 40' modified to 44'.

So, I added the Fisher Panda mini digital 9 Kw, it contributes 46 amps in 220v configuration, so I can run one reverse cycle AC and the charger or both AC units, plus galley. 50 gal of diesel lasts about week.
Inside helm shows voltage of each bank, outside helm displays each motor's amp draw plus or minus, I have no idea what SOC or charger out put is, BTW is a Zivan 144v.
I'm going to include my motor plate for all you electrical engineers out there to run the math, I'm looking for feed back.
Heat is my main concern, Servo amplifiers do not heat up, the TENV PM motors will get warm after an hour or so. Let me back up.
When I bought her, the boat would not accelerate, I splashed her after the big gen install new battery's, (Duracell AGM 105 AH) and a 2.5 hr stress test tied to the dock I fried the starboard amp, so I pulled the motors sent them for inspection, new bearings, new Hall effect sensors, insulation, then contacted Advanced Motion Controls (Nash Dingman) for new amps, after a few months of schooling and no fires or sparks we were moving again. I added huge heat syncs to the amps and pancake fans, I did not have a O scope to tune the drives, I did it by the seat of my pants, its not perfect, nor am I, it works! Its tuned in Duty Cycle mode. Which meant it will quit on low voltage, 36v and high175v.
I turn on the rear Ac unit and have box fans blowing into the motor compartment's because I'm worried ill over heat, the highest motor case temp I've reached is 146 degrees, taken with a thermal laser, I don't think that's HOT but I'm not sure either. I've never pushed the amps over 18, and when I engage the motors it shows about 3.2 average amps after a spike to 6 on start up and the boat moves about 3knts in ideal conditions. I want to know how hard I can push with out blowing fuses or melting wires? I want to install a BMS so any brand names please post links if you have them?
I want to convert the TENV NEMA 180 cases to TEFC (fan cooled). Cameron @Power Tec will someday answer my emails where to get the fans.
Props are 15 inch, I don't know the pitch, I think the boat is 13 tons displacement I could be wrong. I would like to know what my range is, mathematical theoretic calculations will do.

Thanks all, attached are the?
 

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The answer to that question has nothing to do with how hard you push your motors, and every thing to do with your wire gauge and fuse size. ?If the system was properly installed then your motors top usage draw should be well under the cable gauge used and the fuses should be rated to protect the wires not the motors. Meaning if the system was properly install, then you should be able to run the motor continuously at max load, and the cables if properly sized should stay under the rates sheathing temperature. ?

You should measure the length of you Cables to and from the motor controllers and the traction battery. Then note the wire gauge then uses an ABYC wire gauge chart to make sure they can handle the continuous max load draw. ?

You can find such charts all over the internet, here is one snatch from google for example:?

On May 23, 2020, at 10:55 AM, john winterrowd via groups.io <sailorboy55577@...> wrote:

. I want to know how hard I can push with out blowing fuses or melting wires?

 

Thanks for the reply, cables from batteries are 00 pacer and look proper for application to the breaker, shunt, solenoid, from there to the wire looks like 10ga pacer with spades that fit the lugs, the same to the motors which are comparative in size to the motor leads. I'm starting to think the motors, or props are undersized or something like that. I see your point, at some point going from 00 cable to10ga is a bottleneck however I have monitored the 10ga wire temps and they don't seem to heat up as much as the motors, but are the motors to hot at 146F? Each are on separate systems and both produce very equal numbers.

Hummmmm?
 

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From a heat perspective, the props could be oversized, but never undersized. ?

The smaller the props the less load on the motor, and if the motor is shaft fan cooled the faster the shaft fan would spin. ?

Your choice to fix that would be either a smaller prop, or more gear reduction. Both choices would introduce some efficiency loses. ??

The amount of heat your motor can handle for continuous use, is dependent on the motors windings insulation heat rating and is therefore completely unique to your particular motor, generally the motor manufacturers should supply that information on request. ?



On May 23, 2020, at 2:37 PM, john winterrowd via groups.io <sailorboy55577@...> wrote:

?Thanks for the reply, cables from batteries are 00 pacer and look proper for application to the breaker, shunt, solenoid, from there to the wire looks like 10ga pacer with spades that fit the lugs, the same to the motors which are comparative in size to the motor leads. I'm starting to think the motors, or props are undersized or something like that. I see your point, at some point going from 00 cable to10ga is a bottleneck however I have monitored the 10ga wire temps and they don't seem to heat up as much as the motors, but are the motors to hot at 146F? Each are on separate systems and both produce very equal numbers.

Hummmmm?

 

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Also, measure how much your battery voltages sag under load.

AGM batteries also dry out and die.

?

Is this the boat that has long been a live-aboard solar catamaran by one of the longtime members in this group (16 years or so) on Yahoogroups?? As I recall, he pretty much gunkholed much of the time on the canal that crosses Florida below Lake Okeechobee.

?

Was his name Captiain Dennis or something like that?

Anyone remember?

?

-MT

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