DIY Electric Car Forums banner
Cancel

DMOC 445 Contactor Not Closing

2477 Views 5 Replies 3 Participants Last post by  rclugnut, 
O
I know this is covered in other threads, but not to the level that it helps me with my problem. I've been having this issue for several months now and I'm just not smart enough to figure it out on my own...

Here's the backstory:
I bought a brand new DMOC 445 and AC24LS directly from Azure just a few months before they went under (when Azure and Electro Auto had the discount). I have the high-voltage setup; 100GBS batts in series (currently showing as 340V at the HV terminals). I ran the motor several times with no issues.
Then it just quit working. No contactor click, no ccShell interface. I sent it to Gary Snyder and it worked fine for him. He sent it back to me and it worked again for a couple of months (maybe used 4 or 5 times).

Now it's just the SOS. No contactor click, no interface.
Last weekend, I tried rigging up a new 35-pin connector with just the basic connections as detailed in the Troubleshooting portion of the DMOC guide, but even that didn't work.

Any thoughts or suggestions would be greatly appreciated!

Thanks!
Josh
Reply
Save
Like
1 - 6 of 6 Posts
T
What are you using for a +12v supply for the DMOC? I have not had a chance to look at a DMOC, but I've repaired many UMOCs that needed the contactor dismantled and cleaned.

You need to make sure you 12v supply is solid, if its too low the DMOC wont show an interface, or close the contactor.

The contactor also wont close if the batteries are under the Low Voltage setting of the DMOC.
Reply
Save
Like
O
I'm using a typical 12V car battery. I think it has about 650 Cranking Amps. I'll check the voltage again (it has been cold lately), but it used to be right at 12V.
One possible issue may be that it's wired through a switch that also controls the BMS... I'll rig up a direct connection to see if this helps.

Thanks for the comment!
Reply
Save
Like
T
opusengineer said:
I'm using a typical 12V car battery. I think it has about 650 Cranking Amps. I'll check the voltage again (it has been cold lately), but it used to be right at 12V.
One possible issue may be that it's wired through a switch that also controls the BMS... I'll rig up a direct connection to see if this helps.

Thanks for the comment!
Click to expand...
12v for a car battery is pretty low, it should be around 12.6-12.8v after a full charge.
Reply
Save
Like
O
Ok, I'll try charging the 12V battery to 100% and see if that helps. It's currently at 11.91V and it's cold outside.
New information for those who are kind enough to read this and offer possible solutions:
ccShell isn't working either (even after setting the affinity to just one processor).
Still no response after disconnecting the Azure Forward/Reverse switch and directly connecting pins 19 & 29 (as suggested in another post).
I re-wired the 12V battery to be much closer to the DMOC, but no help there either.
I double checked the HV voltage (still at 331V) at terminals.
Potbox resistances are all good.

Key questions/differences from last time this happened:
Resistance between Pin#29 and Pin#20 is now 10.6ohms (not 2.4ohms)...
Should Pin #12 be grounded to the frame? (it is currently connected)
Does the pedal/potbox need to be isolated from the frame? (it is currently not isolated)

Thanks!
Josh
See less See more
Reply
Save
Like
R
Pin 20/29 shouldn't be connected from what i can tell. I'm attaching a few manuals i've collected... It's been a while since i've worked with this system so it's hard to say.

Attachments

Reply
Save
Like
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
DIY Electric Car Forums
A forum community dedicated to DIY electric car owners and enthusiasts. Come join the discussion about electric vehicle conversions, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more!
Full Forum Listing
Explore Our Forums
All EV Conversions and Builds Batteries and Charging Technical Discussion New Member Introductions eBay EV-Related Auctions
Top