5kW inboard motor on a sail boat

[Jackmoore]

(This thread started with the headline "Why does motor spin backwards and only slow?")

Hello everyone,

We ordered a motor and a controller from GoldenMotor and are having some trouble at getting it to run properly. We are not at all experts on this matter and might have done something really wrong. Perhaps someone can tell us what we could do?

So, there's a 5kW air cooled HPM5000A motor connected to the boat axle / propeller and a VEC300 controller. We were able to connect a Samsung S4 Android phone to the controller via Bluetooth (Android 5.0.1). We are using an app called EZ-Outboard version 1.1 (EZ-Outboard0123.apk). From the phone we can see volts, rpm, current, temp and setting (eco, sport, normal). Picture attached, where the power is on but the motor is in idle (throttle is at zero).

Symptoms / behaviour:

- When the motor is NOT connected to the boat axle & propeller, the motor spins quickly
- When the motor is connected to the boat axle & propeller, it only spins ~600 rpm backwards and ~300 rpm forwards
- The motor spins the wrong way: when throttle is pushed forward, the boat moves backwards and vice versa

Parts list:

- HPM5000A 5kW Air Cooling BLDC Motor
- VEC300 48300 Sine Wave Controller
- TRC-010L RemoteThrottle Set (Left Hand)
- BL0001 Bluetooth Adaptor for EZ
- Samsung S4 Android phone

Thanks in advance, all comments welcome! 

[Bikemad]

Hi Jack andto the forum.

If the propellor is spinning free in the air, it could be a problem with tight propshaft bearings/seals.
However, if it only does this when it is submerged in water, then I suspect that the propellor is either too large or has too much pitch, in which case, you may have to use a different propellor or add some form of reduction gearing between the motor and the propshaft if you don't already have it.

How much current is it drawing at 300rpm and 600rpm respectively, and how low does the battery voltage drop in each case?

To reverse the motor's default direction of rotation from clockwise to counterclockwise you will need to swap the Blue and Yellow Phase wires and the Green and Yellow Hall sensor wires.

I suspect the the Forword speed ratio (%) parameter needs to be increased from 85% to 100% to obtain the same speeds for forwards and reverse, but I don't know whether this setting can be changed via Bluetooth, or whether it requires the PC programming lead and PC software. 

I have not seen the EZ outboard App in use before and I'm wondering whether the speedometer is directly linked to the motor rpm or whether it uses GPS.

Alan
 

[Jackmoore]

Hello Alan,

And thank you very much for your response. From your message history, I can see that you are an invaluable member of this community. Keep up the good work!

See below for data (rpm, volts, amps) from yesterday's test run and a question: how hot can we run the motor without damage?

- With your help, we got the motor spin direction reversed and it now operates the right way (throttle forward --> boat forward and vice versa). Thanks! 

- The EZ-Outboard Android app does indeed use GPS to measure speed

- The motor is installed inboard directly to the axle, no gears in between. When the motor is powered off, we can spin the axle by hand so we think there is not a huge resistance / power loss there. Having said that, we might need to investigate the bearings a bit at some point.

- The propeller is always submerged in water. We are under the impression that the propeller size and pitch should be ok for now. (But this is a topic of some controversy, it seems: https://www.boatdesign.net/threads/propellor-selection-electric-drive.50422/) Our propeller was used with a 10 HP diesel engine for years. The diesel broke down last summer and we decided at that time to go electric.

- Slower backward speed is not a big problem. Maneuverability is ok as it is, but could be even better with higher backward speed. We wonder if there is a reason why the backward speed is set to slower and if not, could we just make it the same as forward speed? (If we can find a way to program the controller)

- You are right, we can’t access most of the controller settings with the EZ-Outboard application. When we tried to order the PC lead and software to investigate, we were told they are not available for this model We have been told from GM that the controller is already set to correct parameters. But, we don't know what they are 

- Programming the VEC300 controller is a complex topic and there seems to be a lot of factors involved. The only manual for VEC300 we could find is from 2014 and it looks outdated (https://www.goldenmotor.com/controllers/GoldenMotor%20FOC%20Motor%20Controller%20Guide.pdf) The invoice we got from GM has a remark in chinese on it which translates to “on-hook version” with Google translator. In its context, we suspect that the translation would be “phone version”, which could mean that the controller is not programmable via PC at all? We are now wondering if we could use some other Android software to access the controller parameters and then switch back to EZ-Outboard application for monitoring after we are done with settings. There seems to be a lot of discussion about different bluetooth software here: https://goldenmotor.com/SMF/index.php?board=15.0

* * *

Data from test run 29th of May

We did a 10 minute test run around the harbor yesterday. Wind was 4 m/s (7,8 knots) which is not very much but it did have a slight effect. The hull speed (https://en.wikipedia.org/wiki/Hull_speed) of the boat is roughly 6 knots.

Forwards (full throttle)
Max speed 5 knots (tailwind)
Max speed 4 knots (headwind)
Max rpm ~600
Voltage drop 50,2 --> 47 Volts
Current 39 Amps

Backwards (full throttle)
Max speed 2,5 knots
Max rpm ~400
Voltage drop 50,2 --> 48 Volts
Current 13 Amps

Temperatures
Motor temperature rose rather quickly to 80 degrees celsius with full throttle and would’ve gotten even higher if continued. We got a bit worried and reduced the throttle / rpm and the temperature got down to 70 degrees. Controller temperature was around 50 degrees celsius. Question: how high are these temperatures? We have been told that both the motor and controller are equipped with overheat protection but we can’t find information on what the safe running temperatures and the protective cut off points are.

* * *

Side note about spinning direction: On March 6th this year, we had the motor fitted to a metal frame as we wanted to test the motor + controller before fitting them to the boat. At that time, the motor wouldn’t spin at all, it would just shake. (We shot a video, you can see it here: https://www.youtube.com/watch?v=6hD6SL8kzPY )  We were instructed from GM to only switch the blue and yellow phase cables. We didn’t touch the hall sensor wires. This got the motor to stop shaking and to spin but we didn’t realise it was spinning the wrong way until we got it running in the boat last week.

Per your instructions, we swapped the blue and yellow phase cables back to original and swapped the green and yellow hall sensor wires. This fixed the direction problem. We are now a bit baffled why the motor wouldn’t spin at all first but only shake? If you have any ideas, would be interested to hear. (Doesn't matter much though, as it works now  )

To reiterate, here’s a description of the wiring setup we have now:

Phase cables

U = Yellow
V = Green
W = Blue

Hall sensor wires

_________                                   _________
|              |                                  |              |
|              |--- Yellow --> Green ---|              |
| CONTR   |--- Green --> Yellow ---|  MOTOR  |
| OLLER    |--- Blue --> Blue -------|              |
|________|                                  |________|

Attachment: Picture of the throttle we use

[Bikemad]

Hi Jack,

Good to hear that you've sorted the default motor direction out. 

Do you know the maximum rpm of the original Diesel engine and whether it had any form of reduction gearing built into the reversing gearbox unit?

A slower maximum rpm in reverse may have been entered to prevent it from going too fast in the reverse direction, as the hydrodynamics of the rear of the hull may not appreciate the higher speed.
It should be possible to set the maximum reverse rpm the same as the maximum forward rpm if you can find a way of accessing the settings.

After seeing your rpm and current readings, it would appear that the controller's battery current setting is either set very low, or the throttle signal voltage is not sufficient to provide maximum power.
If you look at the dynamometer figures, that motor should be pulling more than 176 Amps if full throttle is applied below 2,500 rpm with a high power controller.
However, the default battery current settings for your controller are typically 110 Amp continuous with a 180 Amps boost available for 20 seconds (with a 90 seconds interval between boosts).
According to your figures, I calculate that your motor is only producing ~1,650 Watts of useable power going forward at 600 rpm and an even more feeble ~560 Watts in reverse at 400 rpm (assuming it's running at ~90% efficiency).

It might be worth measuring the throttle signal voltage to check that it is ~1.15-1.2V at full throttle in reverse and ~3.2-3.25V at full throttle going forward.

Regarding the motor temperature, the default program settings show a "level 1" reduction of current @ 120°, a "level 2" reduction @ 130°, and the controller would cut the motor completely @ 150°, but the motor temperature protection appears to be disabled by default on the settings I've seen. 
So you should be good as long as you don't exceed 120° if the temperature protection is disabled. 

In your video, the Blue and Yellow Phase wires are in the wrong position for normal operation, which is presumably why GM told you to just swap those two over.
If you look at the wiring diagram, you can see the phase wires are in the same order from left to right as yours are in the video, but your controller is upside down in the video compared to the one in the wiring diagram. 

Does the three position switch on your throttle make any difference to the motor rpm/power?
I presume it is for Economy, Normal and Speed when the three gear function setting has been enabled in the controller (this function was also disabled by default on the VEC300 settings I've seen).
If the function is enabled without a three position switch wired up it would presumably default to 80% speed instead of 100%.
If the function is enabled and the switch is in the "E" position, I would expect  the speed to be limited to 60%.

I hope this all makes sense.

Alan
 

[BjornO]

I use the same motor and controller on my boat. Initially I used a reduction rate of 1:2, but later changed to  1:3. This makes the motor spin faster and would not become too hot. The prop speed at normal boat speed is 740 rpm, equal to a motor speed of 2200 rpm.

[Jackmoore]

Hello,

Thank you Alan & Bjorn for your messages! Very helpful information. 

We ordered the PC programming cable and it arrived today. I think first thing to do is to download and save  the factory settings to computer and examine them. Unfortunately, we can't measure the throttle voltages, the wires are packed inside the handle. We will check the VEC settings against the figures Alan commented and send findings here later.

Question to Bjorn; we are interested about your VEC settings? If you have them available, they might be useful for reference as well. But don't bother if you have to download them or something.

Jack

[Jackmoore]

Hi Alan,

We have trouble connecting to the controller. Similar issues as here: https://goldenmotor.com/SMF/index.php?topic=5694.msg32327#msg32327

Unfortunately, the Dropbox link to the older version of the software doesn't work anymore, I guess the file has been taken down. Would you happen to have the older software (Original LBMC_GUI_v3.1.2_GoldenMotor.exe) that Nick recommends in his post? (https://goldenmotor.com/SMF/index.php?topic=5694.msg32328#msg32328)

Edit: Never mind, forgot to click "Connect"

Edit 2: Uploaded controller factory settings and saved them to PC. Screenshots attached. Overheat protection is enabled but the values seem a bit high: 180, 170 and 160


Jack

[Bikemad]

Edit 2: Uploaded controller factory settings and saved them to PC. Screenshots attached. Overheat protection is enabled but the values seem a bit high: 180, 170 and 160

I'm not sure where those figures have come from as your screenshots taken of the "factory settings" show it as 120, 130 and 150 (exactly the same as the figures that I previously posted)

Alan

[Jackmoore]

Hi Alan,

Yes, I accidentally posted the wrong screenshot, sorry. On that one, we already had changed the settings to the ones you recommended.

We changed the following settings yesterday:

- Rated motor speed (rpm) changed to 3500 (was 2800)
- Motor current limit temperature (level 1) to 120 (was 170)
- Motor current limit temperature (level 2) to 130 (was 180)
- Maximum motor protection temperature to 150 (was 190)
- EBS enable to Disable (was Enable)
- 3-Gears enable to Disable (was Enable)

Thinking behind the change of rated rpm was that the 5kW motor rated rpm is reported as 3500 rpm on their Dynamic test sheet: https://www.goldenmotor.com/eCar/HPM48-5000.pdf Question: why do you think it was set lower? What effect does the rated motor rpm setting have? We don't need regenerative braking, so we disabled that. Also we don't think we need the 3 gear setting, as the motor is almost exclusively used when leaving or arriving to pier. We can adjust the power from the throttle lever. So disabling the E/N/S setting would be ok, wouldn't it?

We took a ~20 minute test run after changing the settings. The log interval was set to 60 seconds. We ran the motor in different speeds and watched the temps. When using less rpm, the motor didn't heat up as much anymore, but the controller kept heating up even with lower speeds and the temperature slowly started to decrease only after we had arrived back and shut off the motor. I fed the log info to a Google Sheet, you can find the data here: https://docs.google.com/spreadsheets/d/1qXc8qK948ndsh9QDXiGmuQrzoToOnB3MP2qJdHrQgc0/edit?usp=sharing (I also drew a chart, click the second tab on the bottom to see the curves)

About the throttle handle: I noticed that the maximum rpm ~650 was reached already on the "half full" position. There was room for the throttle to go even more forwards, but pushing it more didn't have any effect to the rpm. This made me think about the throttle voltage settings, but we didn't change them yet.

One a bit puzzling finding was that the Maximum phase current (A) setting and Battery drawn current limit (A) setting couldn't be changed. The software simply wouldn't accept any other values than were already put in, but reported an error that the figure is wrong. The settings couldn't be saved before those values were set back to original.

Motor temperature seems to react well to rpm and we are less concerned about that now. But the controller didn't respond to lower rpm at all. We are now wondering how hot can we run the controller? We are installing a small 12 volt PC fan today, trying to keep the controller a bit cooler.

We will do another test run today.

[Jackmoore]

Hello,

We didn't change the controller parameters today. The only thing we changed was the controller position and cooling. We took it off the wall about an inch and installed a 12 volt PC cooling fan on the side, blowing air to both sides. This had significant effect on the cooling. Data from today's test run here: https://docs.google.com/spreadsheets/d/1l00sVJROqTUtUweROwurjlAQoUUs2dxWpwaJceLuYk0/edit?usp=sharing

The controller temperature didn't rise as dramatically as yesterday. Also, after return to pier we shut off the motor but left the PC fan on. In 15 minutes, the controller cooled down from 61 degrees to 44 degrees = 17 degree drop. Yesterday in the same conditions but without cooling fan and controller installed directly against wall the controller cooled down in 15 minutes from 67 degrees to 58 degrees = 9 degree drop.

Running the motor at ~400 rpm seems to be very economical. Granted, the speed is only around 2,5 knots but power usage grows exponentially and temperatures rise quickly above that. We might take the reduction gears under consideration. But that has to wait until next summer

Comments welcome as usual.

[Bikemad]

Hi Jack,

I have edited your screenshots together into a single file for ease of viewing:

We changed the following settings yesterday:

- Rated motor speed (rpm) changed to 3500 (was 2800)
- Motor current limit temperature (level 1) to 120 (was 170)
- Motor current limit temperature (level 2) to 130 (was 180)
- Maximum motor protection temperature to 150 (was 190)
- EBS enable to Disable (was Enable)
- 3-Gears enable to Disable (was Enable)

Thinking behind the change of rated rpm was that the 5kW motor rated rpm is reported as 3500 rpm on their Dynamic test sheet: https://www.goldenmotor.com/eCar/HPM48-5000.pdf Question: why do you think it was set lower? What effect does the rated motor rpm setting have? We don't need regenerative braking, so we disabled that. Also we don't think we need the 3 gear setting, as the motor is almost exclusively used when leaving or arriving to pier. We can adjust the power from the throttle lever. So disabling the E/N/S setting would be ok, wouldn't it?

The rated motor speed basically limits the maximum rpm of the motor, but I don't know why it would have been reduced without knowing the installation details of the motor.

As the three speed settings are all currently set to 100% it shouldn't make any difference whether the switch is enabled or disabled.

About the throttle handle: I noticed that the maximum rpm ~650 was reached already on the "half full" position. There was room for the throttle to go even more forwards, but pushing it more didn't have any effect to the rpm. This made me think about the throttle voltage settings, but we didn't change them yet.

As you motor's rpm seems to be severely limited by the excessive load of the directly driven propellor, I suspect you would have a more linear throttle response if you set the rated motor rpm just above the maximum achieved rpm (i.e. 650~700).
A smaller diameter and/or pitch propellor or some form of additional gear reduction would allow higher motor rpm to be used, which would probably improve both the cooling (due to the higher cooling fan speed) and the efficiency of the motor, and the reduced motor load should also allow the controller to run cooler as well.

One a bit puzzling finding was that the Maximum phase current (A) setting and Battery drawn current limit (A) setting couldn't be changed. The software simply wouldn't accept any other values than were already put in, but reported an error that the figure is wrong. The settings couldn't be saved before those values were set back to original.

The acceptable range for the parameter values that you are allowed to change are governed by the controller itself.
If you are unable to set the Maximum phase current higher than 200A, I am wondering whether you may actually have a VEC200 controller instead of a VEC300 controller.
Although, the VEC 200 controller should still be able to accept a Maximum phase current value of 210 Amps. 

I would also increase the Reverse torque ratio (%) from 55 to 100 for improved reverse thrust.

Alan
 

[Jackmoore]

Hi Alan,

Thank you for seaming the screenshots together 

The controller has a sticker on it that reads VEC-300. I guess it's possible that the software is wrong, but as we are not using the whole power at the moment, we don't need to adjust the currents.

We adjusted the motor rated rpm to 800. This had a good effect on the throttle function, now the whole range of handle movement is available for adjusting the rpm. We also changed the reverse torque ratio setting to 100 % as you recommended. As expected, the reverse power increased and the boat is much more maneuverable. This very good. We did a short test run this morning and data is available here: https://docs.google.com/spreadsheets/d/11wMe_03LkJyfzHot63u1X5ueQ1F-NJB6invuEIe4wyE/edit?usp=sharing

Moving at ~450 rpm gives 2,5 - 3,0 knot speed on a calm weather, which is ok. Running the motor at this speed, the power consumption is more favourable and the controller temperature keeps around 40 degrees. Full rpm (625-650) heats up the controller very quickly. But, full power is only needed when arriving to pier on windier conditions. We got information from GoldenMotor that the controller starts to limit current when it reaches temperature of 70 degrees.

This is our last test day for a while. The motor now works well enough for this summers trips. Additional adjustments can be made next year.

Thank you Alan very much for your help with everything. We toast our glasses at your general direction, sir! 

Also thank you to Bjorn for the tip and picture on your setup of reduction gears. Similar solution or a smaller prop is definitely under consideration for next year.

Jack

[Jackmoore]

Hi Alan,

Long time no post but let's see if this reaches you

We changed the propeller this year and got the rpm up a bit. This improved efficiency. I'm not at the boat now, and can't provide data but I'll try to arrange something to this thread later on.

I have a question too. Would you know what is the recommended storage temperature for the motor and the controller? We didn't bother to disassemble the setup from the boat for the winter and the boat was in a cold storage. The controller is now behaving a bit strange and seems to report wrong temperature. We are wondering if it didn't like being alone in the cold  I don't have exact numbers at the moment but we'll do some measurements later on.

Also, do you know if the controller temperature protection settings can be adjusted from the software? There is a setting for the motor (screenshot) but I can't see the controller temp settings. Can't check this from the software either atm, as I'm not at the boat.

Yours,

Jack

[Bikemad]

Hi Jack,

I am not aware of any specified storage temperatures, but if the temperature sensor in the controller is playing up, it is more likely to have been caused by a humidity problem rather than just temperature.

I had a similar problem on one of my Vectrix electric scooters with temperature boards mounted directly to the cell's terminal on the battery:



Moisture must have caused a build up of corrosion on the temperature board which allowed high battery voltage to track across to main temperature control unit causing it to die, which subsequently prevented the charger from working. 

This is what the tracks on a similar PCB look like without any corrosion:



Unfortunately, I don't know if the thermistor (presumably surface mounted on the VEC300 controller's circuit board) is exposed or covered in a conformal coating. but I suspect that a build up of corrosion across the two sensor contacts would effectively reduce its resistance, resulting in an incorrect (high) temperature measurement which could upset the controller operation.

I ended up disconnecting the two temperature sensor control boards and installed alternative charging firmware to override the battery protection error and allow the battery to charge again.
I'm not too concerned about temperature protection on the NiMH battery as the new firmware only charges at a maximum of 6 Amps instead of 12 and also to a lower maximum voltage, so the battery no longer gets hot while charging.

As far as I am aware, there is no adjustment for the controller temperature protection on the VEC300 controller.

You could try temporarily disabling the motor temperature protection to see if the problem is the temperature sensor within the motor rather than the controller.

Alan
 

[Jackmoore]

Hi Alan,

Thank you very much again for your insight. I still haven't had a chance to see the situation my self, but I will pass this forward.

I'll post again when I get more information.

Jack