Community Forums

red_georgia · 09-11-2016, 06:16 PM

So completed upgrading my 06 HVAC to 15KBTU heat pumps today and in the process found the front AC breaker was leaking 37volts when off. Sooooo...open up panel to replace that and then found this (see pic). Incoming 50amp service common wire with some type of component on it right before the bar that has exploded/got hot and clearly almost started a fire! There are no electrical anomalies on the coach anymore (after swapping that breaker) and I'm fairly aware of electrical components (replace all the hvac myself) but have no idea what this thing is????? This coach has a progressive industries circuit protection system on it but not from new so perhaps that add by previous owner was due to whatever caused this problem. In any case, seems clear I need to replace feed wire....but no idea what that "thingy" is on the common that blew up. Anyone? Behuler? Behuler?

palehorse89 · 09-11-2016, 06:20 PM

Never seen such a thing......

jacwjames · 09-11-2016, 06:23 PM

Almost looks like a coil that is used to measure amperage. I installed something that look like this when I had to replace my Intellitec EMS board and a new load center.

dmastroluca · 09-11-2016, 06:37 PM

Quote:

Originally Posted by jacwjames

Almost looks like a coil that is used to measure amperage.

It might just be a current sensor since it connects to the neutral bar. If the other end of the wire goes to your auto transfer switch, then it probably is/was the current sensor.

The transfer switch might of gone "toes up" at some point causing that sensor to fail.

BennieH · 09-12-2016, 10:10 AM

It is a current sensor and it did not cause the burned wire. What most likely happened is that the terminal was not tight at the Neutral bar. That loose connection was the point of heating, caused the wire to heat up which heated the current sensor and the plastic mount for the bar is also melted.
Seen similar things happen in my work life as well as on one of our previous coaches.
I do check/retighten all my connections on a yearly basis now.

red_georgia · 09-12-2016, 10:33 AM

Thanks, makes sense. Confused how that sensor works since it isn't connected to anything other than the wire???? I'm assuming it needs to be replaced? Is that something that just slides on the wire or is it "fixed" on the wire and I need to order a specific feed wire/harness for from transfer switch to breaker box?

BennieH · 09-12-2016, 10:45 AM

There should be 2 smaller wires from the sensor that go to the power management system or power display. The sensor works by "sensing" the magnetic field found around the large cable. The higher the current in the cable, the larger/stronger the magnetic field.
Hope that helps.

YC1 · 09-12-2016, 10:59 AM

There most likely was a wire connected to the ball. It is just a simple current sensor that has been overheated. I'm glad you found this.

I am sure everything will receive some tightening.

Dennis_K · 09-12-2016, 11:32 AM

I agree with the others in that the object looks like a current sensor coil.
Another possible reason for the over heated neutral wire could be an overload condition caused by an incorrectly wired 50amp pedestal in that both legs were connected to the same phase (L1-L2=0 volts). This causes a potential 100amp through the neutral instead of 50amp. Adding a current sensor to the neutral is a way to detect this condition and either it didn't work or was added after the fact.