Wire break

[prb238]

Ok - so this season started out not so great for me.  I got my robot ready, turned on the power for the signal generator and I see a solid green light staring back at me.  I check the obvious places in the wire but find nothing out of place.  I tested a small section of wire by connecting it to the charging base and sure enough I get the blinking light on the signal generator.  I was hoping not to have to replace that.

So, I get out my signal tester, hook it up to the wires and start going around my yard - and I swear that I got a signal all the way around.  I walked around the yard again and still got a signal all the way around the wire.  So now I am thinking - what do I do next?

I ended up pulling up some of the wire and didn't find any breaks in the wire.  I gave up for the night and went at it again the next day. 

I set up the signal tester again and this time I got a section that was silent.  I quickly narrowed down the spot and sure enough I had a break in the wire.  I am not sure what I was doing the first day but obviously I was doing something wrong! 

The wire break was likely because I wasn't careful enough with the aerator that I used last fall and I think I ended up slicing into the wire around one of my mulch beds.

I patched up that section of wire and I am good to go now for season 6.

[glatiak]

Funny thing, I had the same problem this Spring as well. Went through the same dance with the signal tracer, same results. Then I decided to check loop resistance -- different story. Turns out there were a couple of places where the insulation had cracked and the wire corroded, also, a couple of joints that had corroded inside the tape -- just offered a high enough resistance to pass a weak RF signal but not quite enough for the robot to see. So it finally stopped.

Problem is, with 700 odd feet of wire out there a binary search needs some help. So as I replaced the bad sections, I divided the loop up with buried pull boxes and did my joints with burial grade wire nuts. So next time I can pop some covers and check resistance for individual segments. And do an overall loop test from inside early enough that it is not a race with the grass to get it working.

The latest LB3xxx manual had notes about allowable loop resistance in the troubleshooting section.

[toolbelt]

You may want to explain what a binary search is for some of the folks here and where they can get burial pull boxes and burial grade wire nuts.
Way back when, there was a big discussion here on what was the best way to make wire connections that ended up under ground.  Soldering eliminates the corrosion problem but doesn't help with the binary search.  Your system may be the best yet.

Starting our 7th season of NOT mowing the grass...... love it....

[RobotLady]

Wire troubles can be a pain.  Just wanted everyone to know we are selling a wire break finder on our site now.  http://www.paradiserobotics.com/lawnbottrobotmowers/perimeterwirebreakcutfinder.htm

We advocate soldering splices, but I understand it can be difficult for some folks to do.  These splicers might be a good compromise - let me know if anyone tries them  http://www.homedepot.com/p/Ideal-Spliceline-42-Orange-In-Line-Push-In-Butt-Splices-10-Pack-30-1342S/202894306#.UZVKOkqhnE0

I'm a bit concerned when I hear about corroded wire insulation.  Perhaps in this case hardware store wire was used.  Always buy wire from us because it is specifically intended for outdoor use and burying.

One more reminder for a trouble-free summer - if you do not have the brushless model, remember to change the motor brushes once per season (large lawns) or once every other season (small lawns).

By the way, there is a new fully sealed fanless power supply available, $240.00.  If you keep your supply outside, the new one is a much better option.

Happy mowing!

Robotlady

[prb238]

I can definitely confirm the lackluster performance of hardware store wire. I did use some in my perimeter wire and just had to deal with the consequences. Not 3 weeks after the previous wire break I again started getting a no signal error.  I used my wire break finder and the only thing I noticed was that the signal was pretty weak in spots, but it was getting a signal all the way around the wire.  It took me several hours until I finally found a spot in the wire around one of my mulch beds where I got a very strong signal on one section and then 4 feet away I got hardly anything. I checked the wire carefully and sure enough there was a section where the wire covering had worn away and the wire was corroded and had just a few strands connected.

I took out that section, replaced it and the signal was strong all the way around the wire.

[prb238]

Ok - so I must have reached the end of life span for the hardware store wire. Been plagued with no signal errors again and I found 2 more spots in the wire that had just corroded all the way through and caused the signal to drop to an unacceptable level.

The hardware store wire lasted about 5 years for those who are wondering. I guess it could be different for others depending on how wet, hot, cold it gets. I live in Indiana so have pretty cold winters and hot summers and shade so some areas stay pretty damp.

I am getting some more of the stock wire and will be replacing all of the hardware wire.

Fun fun .....

[RobotLady]

prb238: Glad to hear you are converting to approved wire.  It's a lot of work to install it, but you will be glad you did.

By the way, we have an open roll of wire right now so we are selling wire by the foot.  The button to order it is on this page:

http://www.paradiserobotics.com/lawnbottrobotmowers/lawnbott500ftwire.htm

It's handy if you have to replace a small section after a break...

Robotlady