- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Here is the scenario
A non grounded 2 wire circuit feeds a 3 gang box box in the kitchen—The 3 gang has a separate feed for the receptacle and it is grounded. Then there are 2 switches that control undercabinet lights and a ceiling exhaust fan that are fed fom the ungrounded 2 wire circuit. There is also a feed to the dishwasher from this circuit
All the undercabinet lights, fan and the dishwasher have equipment grounding conductor’s in the cable which are tied together at the load as well as in the box.
Countertops and cabinets are metal and there is phantom voltage on the equipment grounding conductor because they are not tied back to the panel. When you touch the dishwasher and the countertop you get a shock?????? I know this is phantom voltage and I know the countertop is not energized. The countertop is grounded thru contact with copper water pipes not thru the dishwasher.
The voltage from countertop to dishwasher went from 5 voltage to 38 v or so depending on how many loads were turned on—ie, undercabinet light or ceiling exhaust. Why?
Also why would you get a shock? I did not think you can feel phantom voltage. I have convinced myself that there is leakage somewhere else but I cannot find it if it exists and the voltage and shock disappeared a soon as I tied the equipment grounding conductor from the receptacle circuit to those equipment grounding conductor’s on the ungrounded circuit.
Problem solved but why a shock???? And why did the voltage vary
A non grounded 2 wire circuit feeds a 3 gang box box in the kitchen—The 3 gang has a separate feed for the receptacle and it is grounded. Then there are 2 switches that control undercabinet lights and a ceiling exhaust fan that are fed fom the ungrounded 2 wire circuit. There is also a feed to the dishwasher from this circuit
All the undercabinet lights, fan and the dishwasher have equipment grounding conductor’s in the cable which are tied together at the load as well as in the box.
Countertops and cabinets are metal and there is phantom voltage on the equipment grounding conductor because they are not tied back to the panel. When you touch the dishwasher and the countertop you get a shock?????? I know this is phantom voltage and I know the countertop is not energized. The countertop is grounded thru contact with copper water pipes not thru the dishwasher.
The voltage from countertop to dishwasher went from 5 voltage to 38 v or so depending on how many loads were turned on—ie, undercabinet light or ceiling exhaust. Why?
Also why would you get a shock? I did not think you can feel phantom voltage. I have convinced myself that there is leakage somewhere else but I cannot find it if it exists and the voltage and shock disappeared a soon as I tied the equipment grounding conductor from the receptacle circuit to those equipment grounding conductor’s on the ungrounded circuit.
Problem solved but why a shock???? And why did the voltage vary