Burnt resistor 20A 6 Fet (36-52V, IRFB3077)

[rhijnv]

Hi

I seem to have had a short after wiring, or at least that was my thinking and when opening up my controller i found the R01 resistor blackened

has anybody replaced this before and am i correct in assuming this is a 200ohm/ 2watt 1% resistor thats what seems to be written on the board on the reverse side, the capacitors don't seem to be a problem

so i am hoping its is just the resistor

 

[fechter]

The resistor drops the pack voltage going to the voltage regulator. If it burned up, either it was the wrong value or there was too much current being drawn by the circuit. On one side of it, you should have pack voltage. On the other side, it should be somewhere between 15v and 36v. At minimum, I'd suggest using a higher wattage rating (physically larger) resistor. You can use two 100 ohm in series, for example, to double the watt rating.

Once you get it replaced, you might try measuring the voltage across it and we can do the math to calculate the heat dissipation.

 

[rhijnv]

All done

I received my ordered resistor and it went in easily

where previously i had 4.3V on the low voltage i now have 5v back again

Interesting i hooked up a throttle directly to the controller when the burnt resistor was still on and the motor ran but slower than normal

it would seem my short was somewhere on the connections in my wiring harness that involved the cycle analyst throttle, ebrake, pas, on off switch so i am rewiring all those

I replaced it with a 200ohm 2w resistor but looking at the resistor old resistor it does look more like a 300ohm resistor, however the pcb markings said 200/2w

Will update when complete, as i bought the grin phaserunner in the wait for the new resistor

Thanks

 

[fechter]

If the 5v line was only 4.3v, it might explain running slower than normal.

It's good to hook everything up and turn it on for a while and see how hot things get. The resistor and 12v regulator should get warm but not so hot it burns your finger.

 

[DogDipstick]

it would seem my short was somewhere on the connections in my wiring harness that involved the cycle analyst throttle, ebrake, pas, on off switch so i am rewiring all those



Thanks

Be careful hooking that PAS back up again.. if you are on 72v or the like.

I just took out two CA3 ( one brand new) with a shorted Torque Sensor. I think water got in there and froze. #2 worked fine until I hooked up the PAS.. then *blink* dead... and Im out the $$$. Riding with no display now.

It is a well known flaw.

 

[rhijnv]

All working perfectly, thanks for all the help

i have hooked it up directly to the motor controller

no heat issues to note at all

waiting on the phaserunner to clear customs cant wait to try that and hook up the ca

it was defintiely a short as the ca was also shorted - i have ordered a pas from Grin which i will hook up in place of my current on

Yes, the battery is upside down, but it seem to be the best way to fit at the moment