Something for Electrical engineers / sparkies to contemplate re earthing concern.
Something for Electrical engineers / sparkies to contemplate re earthing concern.
(OP)
I have a problem / transient / conundrum whatever you want to call it either in my house electrics or from an external source.
Background:
New house, 3 phase incoming, split over 5 RCBO covering all power outlets (LNE) plus 12 CB’s for other circuits including the ac units and water heaters (8 units) they are also LNE.
Location is Thailand, therefore all electrics are suspect as the wiring code is at the whim of the “electrician” although I believe that the installation in my case is 100% as it undertaken by an experienced industrial electrician carefully watched over by myself. However, what is in the street and the way the street lights are wired, transformers installed etc. is anyone guess.
[b]Problem / concern / looking for understanding.
On one of the power outlet, I have a power board for the TV, DVD, satellite system etc. The power board has two indicating lamps incorporated. 1. Power-on, 2. Indicates earth disconnected if both power and the second lamp is on.
During the day only the power indicator is on, early evening and night the earth disconnect indicator comes on and goes off early morning, earth disconnected light comes on at the same time as the housing estate street lights come on and goes off in the morning when the street lights go off.
Have checked during the day, L-N 220V, L-E 220V, N-E Just a flicker maybe 1V.
After the street lights come on L-N 220V, L-E floating a bit 210V, N-E 27 /28 V.
Further, I have just installed a new on demand water heater in the bathroom, this has 3 lights, power, ELCB and earth, during the day the earth lamp is on but off during the evening / night. As with the power board, this also coincides with the street lights coming on /off.
To date there has not been any apparent problems with electrics, no tingles or bites from computers, washing machine etc. The only exception to this is, in the 2 years we have been in the house, the RCBO on the water pump has tripped twice during the night, now it’s possible that the pump wasn’t even called to come on line during the time of going to bed and getting up in the morning. It’s unlikely a moisture problem with the pump / cables etc. as the pump is well protected from the elements in a dry area and the pump has never trip the RCBO during the day / when working.
My feeling is it is a problem coming from the street lighting and the way it is wired into the power supply in the street.
Thanks
Any thoughts / ideas / suggestions are most welcomed.
Background:
New house, 3 phase incoming, split over 5 RCBO covering all power outlets (LNE) plus 12 CB’s for other circuits including the ac units and water heaters (8 units) they are also LNE.
Location is Thailand, therefore all electrics are suspect as the wiring code is at the whim of the “electrician” although I believe that the installation in my case is 100% as it undertaken by an experienced industrial electrician carefully watched over by myself. However, what is in the street and the way the street lights are wired, transformers installed etc. is anyone guess.
[b]Problem / concern / looking for understanding.
On one of the power outlet, I have a power board for the TV, DVD, satellite system etc. The power board has two indicating lamps incorporated. 1. Power-on, 2. Indicates earth disconnected if both power and the second lamp is on.
During the day only the power indicator is on, early evening and night the earth disconnect indicator comes on and goes off early morning, earth disconnected light comes on at the same time as the housing estate street lights come on and goes off in the morning when the street lights go off.
Have checked during the day, L-N 220V, L-E 220V, N-E Just a flicker maybe 1V.
After the street lights come on L-N 220V, L-E floating a bit 210V, N-E 27 /28 V.
Further, I have just installed a new on demand water heater in the bathroom, this has 3 lights, power, ELCB and earth, during the day the earth lamp is on but off during the evening / night. As with the power board, this also coincides with the street lights coming on /off.
To date there has not been any apparent problems with electrics, no tingles or bites from computers, washing machine etc. The only exception to this is, in the 2 years we have been in the house, the RCBO on the water pump has tripped twice during the night, now it’s possible that the pump wasn’t even called to come on line during the time of going to bed and getting up in the morning. It’s unlikely a moisture problem with the pump / cables etc. as the pump is well protected from the elements in a dry area and the pump has never trip the RCBO during the day / when working.
My feeling is it is a problem coming from the street lighting and the way it is wired into the power supply in the street.
Thanks
Any thoughts / ideas / suggestions are most welcomed.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)






RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
Your water pump RCBO is tripping due to the evening ground/power disturbance. Either when they end during the morning or during the evening switch. It likely depends on the actual instant in the power sine-wave that the lights go on or off, hence the "occasionalness" of the trips.
Since your ground seems to rise considerably during the streetlights I suspect the streetlights are incorrectly using the earth (E) ground for their return. It can also mean your street's E connection is missing or really poor.
Does your power company send you a ground wire at all?
Is your home's neutral bonded to E at your service entrance?
Does your house have a ground rod and is it tied to your service entrance?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
1> Street lights are improperly wired and are passing neutral current through ground.
2> There is a problem with the connection between ground and neutral in your panel.
If the ground conductor is solidly connected to the neutral bus in your panel your problem may go away.
Well partly go away. The lights should go out but your ground may be elevated above earth ground by the street lights.
Check in your panel for a voltage difference between the ground bus and the neutral bus.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
I think he did Bill:
Keith Cress
kcress - http://www.flaminsystems.com
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
Keith. Thanks for the reply, seems to be what I thought although well outside my field to make such a statement.
1. Doesn't look like any ground wire via the power company - 4 wires coming into the meter, which I assume is the 3 phases plus a neutral.
2. not sure if the neutral is connected to the earth - but I feel it is unlikely. Will check if possible but from memory all earths were terminated in the roof with one wire going to the earth rod.
3. I have a ground (earth) rod but unfortunately the connection is now below the concrete - no co-operation between trades here - but would think it was correctly terminated initially - one job done while I was away from site.
Scotty:
Thanks, If the problem is external to my house / system which I feel is probably a fact, to have any rectification work done is probably very unlikely, especially since everything seems to be working Ok, that's in the eye's of the power supplier.
I would think itsmoked is probably one the mark - the problem is independent of any load on my system. During the evening / night the load is virtually zero, a refrigerator and 2 / 3 low wattage lamps - weather is cool so no fans or a/c units running.
Assuming that no action is forthcoming from the power company - do you see any problems with the system as it is.
Thanks.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
Thanks, see my comment to Keith point 2, something for me to check.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
The (North American) rule for systems at less than 150 Volts to ground is that the neutral and the ground must be bonded together in the main service panel and then kept separate throughout the rest of the installation.
While the rule as such may not apply in your jurisdiction, if followed it generally assures proper operation of GFIs with no nuisance trips.
I missed this Keith.Sure looks like no connection.
After making the connection, there will be some current from other loads outside your house returning to the transformer through your neutral connection. I would suggest checking that the current is not excessive.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
Today installed a temp. earth rod in the ground (even damped down the surrounding area to ensure good contact) and checked from a GPO in the evening - street lights on L-Earth rod 195 / 205V, N - earth rod floating 25 - 32V, E - earth rod 0V.
Also rechecked from 2 GPO's (evening) same as reported earlier approx. N-E 27V.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.
Keith Cress
kcress - http://www.flaminsystems.com
RE: Something for Electrical engineers / sparkies to contemplate re earthing concern.