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| Thread ID: 45385 | 2004-05-21 00:46:00 | OT.One for Billy or godfather perhaps. | Neil McC (178) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 238016 | 2004-05-21 00:46:00 | I have a client who has a Gallagher electric fence unit in his shed.His home stay cottage 100 odd meters away has a light dimmer that flickers when the fence is on.He's disconnected all the fences,it gets worse.He took the unit inside his house,from where the shed gets it's power.And no problem.Gallagher suggested he got the shed wiring checked.He's checked the main earth following my instructions.Good connection in wet earth.And the same with the unit's earth.It's obviously feeding back out to the road and down to the cottage through the mains,but how to fix it?Or should it be returned to Gallaghers?And why should it stop when in the house?All this by phone so far of course!! ?:| |
Neil McC (178) | ||
| 238017 | 2004-05-21 01:09:00 | Two options come to mind: 1) He is at the end of a long rural power line of the single wire/earth return system, a few of which still exist in the rural back blocks, or he is a long way from the local supply transformer, and the bites the fence takes out of the mains are sufficient to cause momentary flicker. He can test that theory by seeing whether the lights dim noticeably when he turns on a major load like an electric stove with oven and elements all on at the same time. Turning them all on then operating the stove switch on and off a few times is an easier way to provoke a result. 2) More likely there is a point of common coupling via induction or common earth coupling which is injecting the spike into the dimmer and causing it to trigger at the wrong time. Diagnosis is difficult for a layperson, but checking for common paths between his supply and the electric fence is a good start. I can think of some reliable cures but they need an electrical backgound to implement. Can you get any more information for us? Cheers Billy 8-{) |
Billy T (70) | ||
| 238018 | 2004-05-21 01:30:00 | Thanks Billy.He's just on the outskirts of Havelock Nth,so no problem with lines or power fluctuations.The only common path would be the earthing and the mains.Might have to call in on him,sometimes customers tell you one thing and you discover that it has nothing to do with the problem at all.Perhaps when he's taken it into the house to try,he hasn't connected the earth.( I am an electrician,but I certainly don't know everything!!)Get back to you. | Neil McC (178) | ||
| 238019 | 2004-05-21 01:38:00 | >He took the unit inside his house,from where the shed gets it's power.And no problem. when he took it into the house did he connect it to an earth (ie the eltric fence earth not the powerpoint earth) ? |
tweak'e (174) | ||
| 238020 | 2004-05-21 02:15:00 | If the problem only manifests itself in the light dimmer, try another brand of light dimmer? Earth coupling and EPR issues with electric fences can be very problematic to resolve. You need to appreciate the instantaneous energy level that is injected into the earth. It may only be microseconds in duration, but its kilowatts in magnitude. |
godfather (25) | ||
| 238021 | 2004-05-21 05:01:00 | Ah wise men, please explain more to humble Grasshopper. Are you saying that electrons from the shed earth are beetling off through the ground to the cottage? Presumably running up it's earth and upsetting the dimmer? How could they get so far unless there was a steel pipe or wire in the ground between the two? What is the difference between induction and common earth coupling? |
Winston001 (3612) | ||
| 238022 | 2004-05-21 06:12:00 | Of course the lights appear to flicker when the electric fence is going. Your eyes will vibrate (like the rest of you) when you hold on to a good electric fence. :D | Graham L (2) | ||
| 238023 | 2004-05-21 06:20:00 | > Ah wise men, please explain more to humble > Grasshopper. 1. On receipt of a Works Order, or cash. > Are you saying that electrons from the shed earth are > beetling off through the ground to the cottage? > Presumably running up it's earth and upsetting the > dimmer? 2. It may not take much to upset the dimmer, the asymetrical trigger on the Triac would be the device likely to be upset, > How could they get so far unless there was a steel > pipe or wire in the ground between the two? 3. Most probably there is a wire between the two. Its called the Neutral, as they are both likely to be on the same LV transformer. > What is the difference between induction and common > earth coupling? 4. See item #1 |
godfather (25) | ||
| 238024 | 2004-05-21 06:35:00 | How about bypassing the dimmer & see if the lights still flicker?? Would prove a point. PJ | Poppa John (284) | ||
| 238025 | 2004-05-21 07:19:00 | The flicker will only be on a dimmed setting, I would bet your dinner (but not mine) on that. Bypassing the dimmer would not then prove anything. Any "noise" on the supply will often move the trigger point of the Triac, more so the more it is dimmed. This causes a very noticeable flick on the dimmed light. This "noise" will be via the proximity of the electric fence earth to the cottage earth, which is connected to the cottage Neutral which is connected to the house Neutral, which is connected to the ankle bone... you get the picture. Some dimmers are much more susceptible than others. Or its caused by UFO's |
godfather (25) | ||
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