150 amp underground service 3 wire 150 amp 30 circuit panel .The branch circuit is a 15 amp 14/3 with ground . 14/3 feeds to a 4" round box , 1 circuit feeds through to another branch circuit in the house , the other circuit feeds a pull chain fixture that has a compact fluorescent lamp in it. The circuit then goes up to a lutron electronic dimmer then to a low voltage 12v transfomer & then to a set of low voltage track heads. The dimmer has a feed wire a neutral wire a load side wire and a ground. When I turn on the dimmer the lights light fine but when I pull the pull chain switch to light the compact fluorescent or turn on the 60 amp 220 v 4 wire range or the 220 v 4 wire dryer the low voltage lights turn off and then come back on. I checked the neutral wires in the circuit , the utility company checked the 3 wire service coming to the house and 3 local electricians cannot find the problem. Help!! I removed and bypassed the dimmer, checked the neutral connections through out the panel and even checked the other devices on both of the circuits being fed by the 3 wire feed and can't find anything wrong. Using an amprobe on the trouble circuit at the breaker panel , I can see an amperage drop but no voltage drop.

I'm having trouble following. To many run-on sentences.


You have a dimmer for low voltage lights and a compact fluorescent light and under "some conditions" the low voltage lighting briefly turns off. Correct?

What happened when you bypassed the dimmer?
What happened when the fluorescent light was removed?
What is the total wattage of the low voltage lighting?

Does the Dimmer have a White Neutral, a black and a red?

The dimmer is an electronic low voltage dimmer . It has a white neutral wire , black feed wire,yellow load to light wire and a green ground wire. When the dimmer is bypassed the same problem occurs ( the low voltage lights dim out and the dim back on when ever I turn on a 220v appliance ) The compact fluorescent pull chain fixture is in the beginning of the 15 amp circuit that the low lights are a part of and not on the same switch leg as the low voltage lights. When I pull the pull chain to light the compact fluorescent the low voltage light dim off and then dim on. With the compact lamp out of the pull chain fixture , the low voltage lights are fine. The low voltage lights total 250 watts & the transformer is rated 300 watts.

Is this correct?
Turning on the fluorescent light causes the low voltage light to flicker.
Turning on the stove or the dryer caused the low voltage light to flicker, the fluorescent light does not have to be on for this to happen.
If you remove the fluorescent bulb form the pull chain bulb holder the stove and the dryer do not cause the low voltage light to flicker.
None of this occurs if you use a regular light bulb in the pull chain fixture.
If this is correct, try reversing the wiring connections to the pull chain bulb holder.

Harold:

Not a bad idea.

Let's say the ideas don't work, but using an incadesent bulb in place of the cf, everything is fine.
1) Look for an LED light replacement.
2) Try a different brand of cf.
3) Try an RFI filter on the cf fixture leads. I can look if this option becomes viable.
If you have a surge supressor handy that has RFI filtering in it, try wiring the cf to it. There are adapters that are 2 prong plug to light bulb. The surge suppressor is just to test, if available.

Gentlemen,
The fluorescent fixture was completely removed from the circuit , the dimmer bypassed and whenever a 220v appliance was turned on the low voltage lights would dim off and then dim on.

Some additional information, the line side of the transformer has a white neutral wire, a black hot feed wire and a green ground wire. The load side of the transformer has a black and white wire which feeds a two wire suspended track which has low voltage heads that get their power source from the sides of the track. The track is not a traditional track but the new style flexible rail track

Let's go FAR away from the problem. I'd like you to measure the voltage across the breakers involved under load and include the mains. You will need a voltmeter capable of measuring low voltage AC on the order of a 300 mV range. You must be careful to avoid meter damage.

When you look at the mains, put a probe on the lug and another on the wire. Yes you should get zero or nearly close to it.

Measuring the voltage across a set of contacts will generally yield two results:
1. Line voltage when the switch is off and a load is connected. This assumes power source in series with switch, in series with load.
2. The voltage across the "short" or the switch. If the switch is bad that voltage drop will be excessive. 1V is considered excessive.

This measurement will be tricky. You need to know the side the breaker is connected to and put one side of the meter to the main lug. Put the other side of your probe to the exposed piece of copper wire attached to the breaker.

Also after using most of the loads in the house, take your finger and feel the circuits breakers. If you have an uninsulated temperature probe do it to the contacts.

This is probably where a thermal camera would come in very handy.