Power poles melting!


#1

Today we wired the drive motors and within a few minutes of driving our power poles melted and started to smoke. Has anyone ever had this problem? I think we were using the 30 amp connectors for the 12 gauge wire… do we need to step it up to 45 gauge connectors?


#2

Please post photos of the melted plastic housings. Please also remove the crimps from the plastic housings and post photos of those. Lastly, did you do a pull test on ALL of your crimps?


#3

If you’re putting them on 40A circuits, yes you must use the 45A connectors.


#4

The 30A connector mating portions are identical to the 45A connector mating portions. The 45A connectors are just “wing” type for larger wire, instead of barrel type. If your wire fits in the 30A barrel connectors, go for it.

I speculate the real issue is connector pins not all the way fully inserted into the housings, and making poor contact. You have to make sure the lip of the front of the connector pin makes it all the way over the little metal spring clip in the front bottom of the housing. I sometimes do this by pushing from the back of the connector pin with a small flat blade screwdriver.

Also yes, bad crimps could also lead to heating.


#5

Insert usual recommendation to use XT60 connectors - as long as you have someone that has decent soldering skills.

Also waits for the deluge of “don’t use them, they’re garbage and not tested” comments…

ETA: Make sure too that you don’t have something else going on, like multiple motors on the same gearbox and one is reversed. Were any of the motors overly hot?


#6

Cims use 14 gauge wire. You want to use the contacts that fit the wire in respective of amperage rating. As others have said the actual mating part of the contact is the same. We have found that the 45 amp contacts fit the CTRE motor controllers the best.


#7

Are your Anderson crimp contacts straight? If they are deformed, they might not make good contact and have a high contact resistance.


#8

you are shoring somewhere so look for the short heating up the wire


#9

Were the contacts properly seated in the plastic housings? The contacts should slide all the way forward and click on the housing’s spring tab. Sometimes contacts can deform and still survive a pull test without actually being fully seated.

If they weren’t seated right, the contact area can be a lot smaller, which increases the resistance and leads to heat dissipating there.


#10

We had this issue in the past when a student used lower rated pins.


#11

Were the wires hot well away from the connectors, and did all four of the connectors show a similar amount of damage? If so, you are drawing too much current (you can check the RIO logs for this).

If you are not drawing unusually large currents, then you had a bad crimp connections at the power poles with the greatest damage (and possibly all of them).


#12

We’ve never used XT60 connectors on our robot but I am familiar with them from personal hobby use. Note that soldering is truly a must there-- crimped XT60’s will overheat too. (There was a recent batch of 3d printers from China that was having melt-down issues because of crimped-on XT60 connectors.)

Also note that you can buy XT60 connectors with pre-soldered pigtails-- Hobby king has both female and male. Soldering to the XT60’s can be a bit tough, but soldering to the stranded wire pigtails in run-of-the-mill.


#13

I’ve not seen the crimp version of the XT60 connectors. We order ours on Amazon and they’re the genuine Amass brand. We’ve used these successfully for the last 2+ years and not had a single issue.

Yes, it does take a better than average iron to solder these, but with some practice and perhaps additional solder flux in conjunction with rosin-core solder, you’ll be sure to get good flow and connectivity.


#14

We use the Anderson Power Pole PP45 for our connections. Soldering is not required, we’ve never had a problem. When we do solder anything, a mentor always inspects the work.