question

sablt194 avatar image
sablt194 asked

Anybody seeing 5 or 6 V on the L Remote Input of a TR smart 18A Isolated?

So in my van I have a TR smart 30A (non-Isolated) from the Mercedes Battery/Alternator to charge the Lithiums while driving. I also have a TR smart 18A (Isolated) From the lithiums to the Mercedes Battery to keep it topped off when the van is sitting. I am using the remote inputs to control on/of of both devices. I have 12V ignition signal to the L input of the 18A and a 12V ignition signal (from the same post) run to the H input of the 30A. Engine running detection is disabled on both devices. What I'm seeing is voltage crosstalk from the 18A L input to the 30A H input because both wires are tied to the same ignition source and thus there is continuity. With no inputs connected to anything I am seeing 5 to 6V on the L side of the 18A. So, when I reconnect, the 18A is putting 6V on the H side of the 30A, and that's enough to make it think it has an ignition signal, and it fires up. So I end up with both B2B running and competing with each other. Anybody else run into this? Can someone check to see if 6V on the L side is normal? Or do I have a defective 18A?

Sorry for the long winded post

Regards,

Steve

orion-tr smart
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
wkirby avatar image
wkirby answered ·

Yes, the L terminal would need to have a Voltage on it in order to sense if it is being pulled low (L) to activate it. In the same way, the H terminal has a Voltage close to 0V so that it can be pulled high for activation.
~6V for the open L terminal is normal.
The port (both H or L) is not isolated, it would not accept signals from battery Voltage or GND if it were isolated.

For your instance where you want to get two different devices to do different things with the same signal source (the vehicle battery) you may need to use dry relay contacts on one or both devices, using dry relay contacts to bridge H and L together to activate or deactivate the 18A or 30A B2B device.

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

sablt194 avatar image sablt194 commented ·
Yep thanks, That's where my brain ended up today. Ordered a DPDT relay to isolate inputs to the 18A and 30A. Should work dandy then.
0 Likes 0 ·