ThunderStruck Motors, LLC 2985 Dutton Ave. Ste 3 Santa Rosa, CA 95407 Tel: (707) 578-7973 Fax: (707) 581-1860 |
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ThunderStruck Motors, LLC 2985 Dutton Ave. Ste 3 Santa Rosa, CA 95407 Tel: (707) 578-7973 Fax: (707) 581-1860 |
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Hi Chris,
Nope, I don't have details concerning the "tied to the dock" stress test since this situation can't happen while underway. I was just curious about max winding temps at loads higher than my boat will generate at full throttle.
Details about my conversion have been posted dozens of times, certainly a few times since yuor first post from January 2012. Here's one from March 2013
http://groups.yahoo.com/group/electricboats/message/23272
and another direct response to a similar question from you in Feb 2012
http://groups.yahoo.com/group/electricboats/message/20984
But it mught help if you can tell us more about your current performance. Your Morgan 41 should be around 13 tons, if so, I personally believe that an ME0913 is undersized for your boat. Your motor speed at 48V nominal should be around 1900 rpm, though the Sevcon Gen4 can artificially push the RPM higher through dynamic field-weakening (?), but I think that your efficiency drops if using that feature. I do not think that the Sevcon Millipak can do the same thing.
Motenergy rates the ME0913 at 125A continuous AC (180A DC into their controller) but my observation has been that the Sevcon Gen4 puts out about 100-110A AC while onsuming 106A DC (according to the Sevcon Clearview display), so the Sevcon Gen4 appears to be considerably more efficient than the Motenergy controller that was used to develop the motor's ratings. I think that the Motenergy controller is similar to the Millipak, which we all know needed heat sinks to operate near full rating. My Gen4 is mounted flat against a bulkhead and has never had a heat issue. My point is that while the Sevcon Gen4 48V size 4 (the common one supplied with marine drive kits) is rated for 180A continuous, I believe that it's potential output is way beyond the ME0913's actual continuous rating, especially when used in the bilge of a boat.
So if you are using a Gen4 and a ME0193 in a 48V nominal system, I suggest that you target for 1900 RPM and a max battery draw of 125A at full throttle in open water. So now you need to figure out your prop and gearing to put you near those specs. I'm sure that you rememebr fromyour earlier inquiries on this particular topic, all the calculations that you can do on paper are based on so many assumptions, that they will produce a rough estimate at best. If the paper guesstimate does not deliver to your performance targets, then you'll have to tweek the configuration and I think that is where you are today.
What is your current gearing? What is your current draw (watts or amps-volts) at full throttle while underway? Do you have any metrics on motor or controller temps besides "too hot". This might help us make some suggestions to reduce the number of trials and errors. But if you don't have empirical data or are not willing to share, then there is a simple evaulation process.
Since your boat is operational, the process is to run your boat at full throttle, let your boat speed stabilize and check your RPM and current. If the drive exceeds your target current without hitting your target RPM, then your boat is over-propped ar the gear ratio is too low. You would need to reduce your prop or increase your gear ratio. If you hit max RPM target without reaching your max current target, then you are under-propped or over-geared. You wouldd need to increase your prop or reduce your gear ratio. If you hit your target RPM at your target current, you're already there. This is a good as your drive can perform. Now if possible, check your motor temperature, if the motor is running cool (well under spec), you might be able to set a higher current target and run the process again, increasing the prop or decreasing the gear ratio. However, running closer to max temp is obviously harder on the equipment and accelerates the eventual end of life for the components. Please note that I did not include boat speed in your targets. Your speed will be whatever your speed will be when the drive is dialed in. If you boat motors at 4kts, 5kts, or 6kts at full throttle and you want more, you'll need to go to a more powerfull motor to get more speed.
So in my boat, I have already hit my performance targets (rpm, current, temp, boat speed) (beginner's luck?) and don't mind that everything runs below 100C. I ithink that this is much better in the long run.
Let me know if you need more info.
Eric
--- In electricboats@yahoogroups.com, Chris Hudson <clh5_98@...> wrote:
>
> Thanks Eric,
> So that would make your battery current at around 125 amps (I'm assuming your system is 48 VDC)? Do you recall your motor current, volts and RPM at that time? Also what is your reduction ratio? Reason is I'm planning a ratio change on my system as my motors get too hot at the speed I'd like to cruise at. RPM are low and motor current too high.
>
> Chris
>
> Sent from my iPhone
>
> On Jun 26, 2013, at 16:40, "Eric" <ewdysar@...> wrote:
>
> > Hi Chris,
> >
> > Just the internal fan on the ME0913. After 45 minutes at around 6000W of current (a load that is only available while tied to the dock), the temp appears to have stabilized right around 100C (it stopped climbing around 30 minutes). I don't know about longer than that, by then my battery bank was down to less than 20% remaining of my usable capacity and I was ready to recharge. I think that ambient air temp was around 75-80 deg F. although I did not make a note of it at the time.
> >
> > Eric
> >
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It seems to me those sealed, finned motors do often run pretty warm,
even hot, under load. You might perhaps just blow a fan straight at
the motor to blow the heat off the fins.
Craig
=====
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Hi Chris,
Nope, I don't have details concerning the "tied to the dock" stress test since this situation can't happen while underway. I was just curious about max winding temps at loads higher than my boat will generate at full throttle.
Details about my conversion have been posted dozens of times, certainly a few times since yuor first post from January 2012. Here's one from March 2013
http://groups.yahoo.com/group/electricboats/message/23272
and another direct response to a similar question from you in Feb 2012
http://groups.yahoo.com/group/electricboats/message/20984
But it mught help if you can tell us more about your current performance. Your Morgan 41 should be around 13 tons, if so, I personally believe that an ME0913 is undersized for your boat. Your motor speed at 48V nominal should be around 1900 rpm, though the Sevcon Gen4 can artificially push the RPM higher through dynamic field-weakening (?), but I think that your efficiency drops if using that feature. I do not think that the Sevcon Millipak can do the same thing.
Motenergy rates the ME0913 at 125A continuous AC (180A DC into their controller) but my observation has been that the Sevcon Gen4 puts out about 100-110A AC while onsuming 106A DC (according to the Sevcon Clearview display), so the Sevcon Gen4 appears to be considerably more efficient than the Motenergy controller that was used to develop the motor's ratings. I think that the Motenergy controller is similar to the Millipak, which we all know needed heat sinks to operate near full rating. My Gen4 is mounted flat against a bulkhead and has never had a heat issue. My point is that while the Sevcon Gen4 48V size 4 (the common one supplied with marine drive kits) is rated for 180A continuous, I believe that it's potential output is way beyond the ME0913's actual continuous rating, especially when used in the bilge of a boat.
So if you are using a Gen4 and a ME0193 in a 48V nominal system, I suggest that you target for 1900 RPM and a max battery draw of 125A at full throttle in open water. So now you need to figure out your prop and gearing to put you near those specs. I'm sure that you rememebr fromyour earlier inquiries on this particular topic, all the calculations that you can do on paper are based on so many assumptions, that they will produce a rough estimate at best. If the paper guesstimate does not deliver to your performance targets, then you'll have to tweek the configuration and I think that is where you are today.
What is your current gearing? What is your current draw (watts or amps-volts) at full throttle while underway? Do you have any metrics on motor or controller temps besides "too hot". This might help us make some suggestions to reduce the number of trials and errors. But if you don't have empirical data or are not willing to share, then there is a simple evaulation process.
Since your boat is operational, the process is to run your boat at full throttle, let your boat speed stabilize and check your RPM and current. If the drive exceeds your target current without hitting your target RPM, then your boat is over-propped ar the gear ratio is too low. You would need to reduce your prop or increase your gear ratio. If you hit max RPM target without reaching your max current target, then you are under-propped or over-geared. You wouldd need to increase your prop or reduce your gear ratio. If you hit your target RPM at your target current, you're already there. This is a good as your drive can perform. Now if possible, check your motor temperature, if the motor is running cool (well under spec), you might be able to set a higher current target and run the process again, increasing the prop or decreasing the gear ratio. However, running closer to max temp is obviously harder on the equipment and accelerates the eventual end of life for the components. Please note that I did not include boat speed in your targets. Your speed will be whatever your speed will be when the drive is dialed in. If you boat motors at 4kts, 5kts, or 6kts at full throttle and you want more, you'll need to go to a more powerfull motor to get more speed.
So in my boat, I have already hit my performance targets (rpm, current, temp, boat speed) (beginner's luck?) and don't mind that everything runs below 100C. I ithink that this is much better in the long run.
Let me know if you need more info.
Eric
--- In electricboats@yahoogroups.com, Chris Hudson <clh5_98@...> wrote:
>
> Thanks Eric,
> So that would make your battery current at around 125 amps (I'm assuming your system is 48 VDC)? Do you recall your motor current, volts and RPM at that time? Also what is your reduction ratio? Reason is I'm planning a ratio change on my system as my motors get too hot at the speed I'd like to cruise at. RPM are low and motor current too high.
>
> Chris
>
> Sent from my iPhone
>
> On Jun 26, 2013, at 16:40, "Eric" <ewdysar@...> wrote:
>
> > Hi Chris,
> >
> > Just the internal fan on the ME0913. After 45 minutes at around 6000W of current (a load that is only available while tied to the dock), the temp appears to have stabilized right around 100C (it stopped climbing around 30 minutes). I don't know about longer than that, by then my battery bank was down to less than 20% remaining of my usable capacity and I was ready to recharge. I think that ambient air temp was around 75-80 deg F. although I did not make a note of it at the time.
> >
> > Eric
> >
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Hi Chris,
Just the internal fan on the ME0913. After 45 minutes at around 6000W of current (a load that is only available while tied to the dock), the temp appears to have stabilized right around 100C (it stopped climbing around 30 minutes). I don't know about longer than that, by then my battery bank was down to less than 20% remaining of my usable capacity and I was ready to recharge. I think that ambient air temp was around 75-80 deg F. although I did not make a note of it at the time.
Eric
--- In electricboats@yahoogroups.com, Chris Hudson <clh5_98@...> wrote:
>
> Eric,
> Do you have an external fan, or is that with the motor's internal fan?
>
> Chris
>
> Sent from my iPhone
>
> On Jun 26, 2013, at 10:20, "Eric" <ewdysar@...> wrote:
>
> > Hi Orest,
> >
> > Propusion Marine has two solutions for water cooling....
> >
> > You'll notice that James rates his systems more conservatively than the motor manufacturer does, he has observed that most drive systems installed in the bilge of a boat do not dissapate heat as well as the same motor on a test bench. So his ratings are based on observed performance, getting temperature readings from sensors installed in the motor windings while in use in a boat. His drive systems will not overheat when run continuously in a boat at rated capacity. I don't know if the other drive system vendors have collected this type of objective data from actual conversions.
> >
> > I personally know that my air-cooled 5.5kW rated system will not exceed 100C while consuming a full 6kW of power deep in the bilge of my boat, the manufacturer of the motor says that the windings must be kept under 150C.
> >
> > Fair winds,
> > Eric
> > 1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kW Lithium batteries
> > Marina del Rey, CA
> >
> >
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Hi Chris,
Just the internal fan on the ME0913. After 45 minutes at around 6000W of current (a load that is only available while tied to the dock), the temp appears to have stabilized right around 100C (it stopped climbing around 30 minutes). I don't know about longer than that, by then my battery bank was down to less than 20% remaining of my usable capacity and I was ready to recharge. I think that ambient air temp was around 75-80 deg F. although I did not make a note of it at the time.
Eric
--- In electricboats@yahoogroups.com, Chris Hudson <clh5_98@...> wrote:
>
> Eric,
> Do you have an external fan, or is that with the motor's internal fan?
>
> Chris
>
> Sent from my iPhone
>
> On Jun 26, 2013, at 10:20, "Eric" <ewdysar@...> wrote:
>
> > Hi Orest,
> >
> > Propusion Marine has two solutions for water cooling....
> >
> > You'll notice that James rates his systems more conservatively than the motor manufacturer does, he has observed that most drive systems installed in the bilge of a boat do not dissapate heat as well as the same motor on a test bench. So his ratings are based on observed performance, getting temperature readings from sensors installed in the motor windings while in use in a boat. His drive systems will not overheat when run continuously in a boat at rated capacity. I don't know if the other drive system vendors have collected this type of objective data from actual conversions.
> >
> > I personally know that my air-cooled 5.5kW rated system will not exceed 100C while consuming a full 6kW of power deep in the bilge of my boat, the manufacturer of the motor says that the windings must be kept under 150C.
> >
> > Fair winds,
> > Eric
> > 1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kW Lithium batteries
> > Marina del Rey, CA
> >
> >
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Hi Orest,
Propusion Marine has two solutions for water cooling. The first is a retrofit cooling unit bolted between the air-cooled motor and the gear reduction unit. This setup along with forced air, has delivered a measured drop in winding temperatures of 30C under full load. You can see it here:
http://www.propulsionmarine.com/electric/7-kw-water-cooled-electric-drive
The second solution uses a water cooled motor, I think that Perm Motors in Germany manufactures the actual motor. This page has pics that show some of the internal cooling passages:
http://www.propulsionmarine.com/electric/10kw-water-cooled-electric-drive
You'll notice that James rates his systems more conservatively than the motor manufacturer does, he has observed that most drive systems installed in the bilge of a boat do not dissapate heat as well as the same motor on a test bench. So his ratings are based on observed performance, getting temperature readings from sensors installed in the motor windings while in use in a boat. His drive systems will not overheat when run continuously in a boat at rated capacity. I don't know if the other drive system vendors have collected this type of objective data from actual conversions.
I personally know that my air-cooled 5.5kW rated system will not exceed 100C while consuming a full 6kW of power deep in the bilge of my boat, the manufacturer of the motor says that the windings must be kept under 150C.
Fair winds,
Eric
1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kW Lithium batteries
Marina del Rey, CA
--- In electricboats@yahoogroups.com, Orest Iwaszko <orestyko@...> wrote:
>
>
> Has anyone used a water jacket of some kind or water tubes like a still from salt water to cool the electric motor . There may be a thread already if someone could steer me to it. Or is it feasible ?
>
> Thanks Orest Port Alberni.
>
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Hi Orest,
Propusion Marine has two solutions for water cooling. The first is a retrofit cooling unit bolted between the air-cooled motor and the gear reduction unit. This setup along with forced air, has delivered a measured drop in winding temperatures of 30C under full load. You can see it here:
http://www.propulsionmarine.com/electric/7-kw-water-cooled-electric-drive
The second solution uses a water cooled motor, I think that Perm Motors in Germany manufactures the actual motor. This page has pics that show some of the internal cooling passages:
http://www.propulsionmarine.com/electric/10kw-water-cooled-electric-drive
You'll notice that James rates his systems more conservatively than the motor manufacturer does, he has observed that most drive systems installed in the bilge of a boat do not dissapate heat as well as the same motor on a test bench. So his ratings are based on observed performance, getting temperature readings from sensors installed in the motor windings while in use in a boat. His drive systems will not overheat when run continuously in a boat at rated capacity. I don't know if the other drive system vendors have collected this type of objective data from actual conversions.
I personally know that my air-cooled 5.5kW rated system will not exceed 100C while consuming a full 6kW of power deep in the bilge of my boat, the manufacturer of the motor says that the windings must be kept under 150C.
Fair winds,
Eric
1964 Bermuda 30 ketch, 5.5kW Propulsion Marine drive, 8kW Lithium batteries
Marina del Rey, CA
--- In electricboats@yahoogroups.com, Orest Iwaszko <orestyko@...> wrote:
>
>
> Has anyone used a water jacket of some kind or water tubes like a still from salt water to cool the electric motor . There may be a thread already if someone could steer me to it. Or is it feasible ?
>
> Thanks Orest Port Alberni.
>
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If you don't mind me asking, why do you need to? If it's a proprietry unit they should provide, if it's your own creation or an off the shelf unit that only asks for air cooling normally then use forced airflow if you can.
Heat exchangers in Maine use should always be either 316 stainless steel or the correct grade of cupro nickel if u want any sort of efficiency, BUT even if you do, mother nature is always out to get you in that environment. If you connect to your motor with anything metal or even run one close you'll get induced currents which will add to the electrolytic action etc etc.
It's ask good on paper and indeed in practice for a while but unless you're a rare preventive maintenance freak, of your lucky your heat exchanger will spring a leak, of your unlucky your electric motor will!!! And seeing it's probably aluminium bodied out will chop first.
Has anyone used a water jacket of some kind or water tubes like a still from salt water to cool the electric motor . There may be a thread already if someone could steer me to it. Or is it feasible ?
Thanks Orest Port Alberni.
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Nice to know wow , beautiful , anything budget minded please ?
like this company?remember you are unique. Just like the rest of us.
From: Orest Iwaszko <orestyko@hotmail.com>
To: electricboats@yahoogroups.com
Sent: Tuesday, June 25, 2013 8:28 AM
Subject: Re: [Electric Boats] disipating heat
I found a water cooling link , but i think someone might have a better solution.On 2013-06-25, at 8:14 AM, Orest Iwaszko wrote:
Has anyone used a water jacket of some kind or water tubes like a still from salt water to cool the electric motor . There may be a thread already if someone could steer me to it. Or is it feasible ?
Thanks Orest Port Alberni.
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