E3 Plus Tripped but showing current

Has anyone had this problem before? Cannot reset E3 as it is showing current. Possible brainfart moment

E3 on what?

150HP motor

Did the protective trip actually open the contactor ? Is the motor actually running ? If you're really measuring current on a stopped motor then there's something wrong with the CTs.

Are you trying the reset over the network or from the actual button on the device ?

Can you tell what feature tripped the E3 ?

An overload trip will not allow a reset until the Thermal Utilization (Parameter 9) is below the OL Reset Level (Parameter 31).

Similarly, a PTC temperature device trip won't allow reset until the PTC measurement is below the PTC Reset Resistance level.

E3's are meant to prevent you from burning up the motor by restarting too quickly after an overload, which is why we don't usually use them on fire pumps.

What we did was go into DeviceNet and change the FLA to 150A, downloaded, then changed the FLA back to 100A. (This is a 100HP motor not a 150HP motor). All this time the motor disconnect was off. In our PLC what noticed the OL bit went off. Been running since. Could be a E3 problem still, as when we go to turn the disconnect off, we are still showing AMPS all over the place.

Why did you change the FLA setting in the first place ? Is this an E3 with the built-in current transformers, or the external ones ?

When you say "the OL bit went off", do you mean that Input Bit 00 went to False after you downloaded a new configuration to the device ?

Bit 00 indicates that the device is Faulted. It makes sense that it would reset to False after you downloaded a new configuration to the device.

when we go to turn the disconnect off, we are still showing AMPS all over the place.

Click to expand...

I'm not sure what to tell you. Put a clamp-on meter on those motor leads to figure out if there really is current flowing through them, and then start troubleshooting.

The E3 in devicenet was showing between 110A to 120A with the disconnect in the off position. Yes, we were looking at the right motor. Pretty weird. Kinda cheated it to reset the OL

CT's are external by the way.

Obviously most CT's don't indicate high current flow when they're disconnected.

My guess is that the E3 might have been disconnected from the DeviceNet and you were reading stale data in the Input tags.

If you were reading live data off the network then either the CTs or the E3 itself are damaged or defective, or you were looking at the wrong E3.

Since you've verified that you weren't looking at the wrong overload on the network, that leaves a defective or damaged device.