Hi everyone, i've been a lurker for a while but now the time has come to make a post.
First of all, this is my setup, wired it up for the first time today:
TL;DR: When I connected the battery power, the connector made a huge spark and exploded with smoke and soot everywhere.
apologies for the quality, i had to use paint to convert the photos to 256 color because of slow internet
I had set up the motor, controller and battery on a table to test everything before installation. The motor was mounted on a CD with the shaft sticking through the hole, and the CD was placed on top of a roll of tape so that the outrunner could spin freely.
The motor phase wires (bullet connectors) were connected to the controller (hole end wires) just by putting the bullet partly through the hole and covering it temporarily with some large heatshrink tubes. The throttle connector had different wiring to the controller so I cut the connector off and twisted the correct wires together. For the Hall sensors I used some staples as jumpers to link the JST-ZH connector to the bigger controller connector. All of these were temporary measures to test if the controller and motor worked. Since the motor was unloaded for testing purposes, I assumed that the motor current would not be significant.
For power the two Multistar 10000mAh lipo batteries were connected in series, with a wiring harness that I made myself out of XT90 connectors and 10 gauge wire. I had difficulty in soldering the wire to the connectors because of a cheap and weak soldering iron and the heat shrink was not fully sealed. However I had tested the connections for short circuits before connecting the batteries and also tested the voltage output after connecting the batteries (about 48.9V). So the wiring harness was confirmed to be working.
To connect the batteries to the controller, I use a banana-XT60 cable for an iMAX B6 charger and an XT60-alligator cable. The banana plugs fit into the holes of the female XT90 connector. The wiring was as follows:
Battery XT90/Explosion/Banana---XT60/XT60---alligator clip/hole end wire-controller
The controller power connectors were hole end wires (The ones that you bolt down, I do not know what they are called) so I clamped them using the charger cable alligator clips. Again, I expected not to draw much current since the motor was running free.
I connected the positive banana plug first. An explosion occurred when I connected the negative. It gave off a very large spark (arc?), I think it was purple in color but I'm not sure since it was momentary. Burnt stuff got sprayed everywhere, and ground zero was covered n soot(?), as were my hands. A lot of smoke was released. Although it has been about one and a half hours since, the smell is still in the room. The outer part of the negative banana plug came off and became stuck to the XT90 connector, which was partly melted on the negative side. I think it may have welded itself to the inside of the connector. The heat-shrink failed and the wires got knocked off on the banana plug's XT60 connector. Some of the insulation on the banana wire has melted. As for the motor and controller, none of their wires have visual signs of damage. The smoke came from around the vicinity of the XT90 power connector.
Both batteries had low voltage alarms connected. These were rated for 3.3V per cell. Prior to the explosion, the total was measured at 48.9V. During the explosion the alarm briefly sounded but I don't know if it was one or both. I presume the large current caused a massive voltage sag? Both batteries seem to be ok as of now, they aren't warm or bulging from what I can tell and the voltage for each 6S block is about 24.6V. The XT90 connectors don't seem to be damaged. Are these safe to use? How much current would you expect to have flown through at the moment of explosion?
Also, the controller's manual said to connect the self-learning wire first, then the power, then the 'door lock' (this was a single thin red wire with the same hole end as the power so I simply connected this together with the positive power-please correct me if this is wrong), then the Hall sensor wires (from what I can make of the bad translation), then the phase wire and then the throttle. However as I was lacking in proper connections I found it easier to wire up everything before connecting the battery power. I don't know if this was a factor in what happened.
I would like to know what could have caused this explosion. I think it might have been my shoddy series wiring harness or the charge cable. Also if the controller is damaged can it damage or short circuit the batteries if i connect it again? In any case, I am going to purchase a premade wiring harness from ebay, and also get myself some crimp connectors and make proper connections to everything (throttle and hall sensors aren't high power so maybe not those yet) before I proceed further.
This is my setup:
Thanks
30kv dual
First of all, this is my setup, wired it up for the first time today:
- Sensored RC outrunner motor
48V generic ebay brushless controller 38A
12S (2 x 6S) Multistar 10000mAh Lipo connected in series
throttle
TL;DR: When I connected the battery power, the connector made a huge spark and exploded with smoke and soot everywhere.
apologies for the quality, i had to use paint to convert the photos to 256 color because of slow internet
I had set up the motor, controller and battery on a table to test everything before installation. The motor was mounted on a CD with the shaft sticking through the hole, and the CD was placed on top of a roll of tape so that the outrunner could spin freely.
The motor phase wires (bullet connectors) were connected to the controller (hole end wires) just by putting the bullet partly through the hole and covering it temporarily with some large heatshrink tubes. The throttle connector had different wiring to the controller so I cut the connector off and twisted the correct wires together. For the Hall sensors I used some staples as jumpers to link the JST-ZH connector to the bigger controller connector. All of these were temporary measures to test if the controller and motor worked. Since the motor was unloaded for testing purposes, I assumed that the motor current would not be significant.
For power the two Multistar 10000mAh lipo batteries were connected in series, with a wiring harness that I made myself out of XT90 connectors and 10 gauge wire. I had difficulty in soldering the wire to the connectors because of a cheap and weak soldering iron and the heat shrink was not fully sealed. However I had tested the connections for short circuits before connecting the batteries and also tested the voltage output after connecting the batteries (about 48.9V). So the wiring harness was confirmed to be working.
To connect the batteries to the controller, I use a banana-XT60 cable for an iMAX B6 charger and an XT60-alligator cable. The banana plugs fit into the holes of the female XT90 connector. The wiring was as follows:
Battery XT90/Explosion/Banana---XT60/XT60---alligator clip/hole end wire-controller
The controller power connectors were hole end wires (The ones that you bolt down, I do not know what they are called) so I clamped them using the charger cable alligator clips. Again, I expected not to draw much current since the motor was running free.
I connected the positive banana plug first. An explosion occurred when I connected the negative. It gave off a very large spark (arc?), I think it was purple in color but I'm not sure since it was momentary. Burnt stuff got sprayed everywhere, and ground zero was covered n soot(?), as were my hands. A lot of smoke was released. Although it has been about one and a half hours since, the smell is still in the room. The outer part of the negative banana plug came off and became stuck to the XT90 connector, which was partly melted on the negative side. I think it may have welded itself to the inside of the connector. The heat-shrink failed and the wires got knocked off on the banana plug's XT60 connector. Some of the insulation on the banana wire has melted. As for the motor and controller, none of their wires have visual signs of damage. The smoke came from around the vicinity of the XT90 power connector.
Both batteries had low voltage alarms connected. These were rated for 3.3V per cell. Prior to the explosion, the total was measured at 48.9V. During the explosion the alarm briefly sounded but I don't know if it was one or both. I presume the large current caused a massive voltage sag? Both batteries seem to be ok as of now, they aren't warm or bulging from what I can tell and the voltage for each 6S block is about 24.6V. The XT90 connectors don't seem to be damaged. Are these safe to use? How much current would you expect to have flown through at the moment of explosion?
Also, the controller's manual said to connect the self-learning wire first, then the power, then the 'door lock' (this was a single thin red wire with the same hole end as the power so I simply connected this together with the positive power-please correct me if this is wrong), then the Hall sensor wires (from what I can make of the bad translation), then the phase wire and then the throttle. However as I was lacking in proper connections I found it easier to wire up everything before connecting the battery power. I don't know if this was a factor in what happened.
I would like to know what could have caused this explosion. I think it might have been my shoddy series wiring harness or the charge cable. Also if the controller is damaged can it damage or short circuit the batteries if i connect it again? In any case, I am going to purchase a premade wiring harness from ebay, and also get myself some crimp connectors and make proper connections to everything (throttle and hall sensors aren't high power so maybe not those yet) before I proceed further.
This is my setup:
- Sensored RC outrunner motor
48V generic ebay brushless controller 38A
12S (2 x 6S) Multistar 10000mAh Lipo connected in series
throttle
Thanks
30kv dual
