General Category > Electric Boat Conversions
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 :D)
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.
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