Purchased a Electrolux Icon double wall over. Pig tail from oven has 4 wires and the wire going from my junction box to my main service pannel has 4 wires. All wires were connected correctly at junction box (verified by electrician). Oven did not function properly. Appliance maintenance guy says my service pannel is not wired correctly, I need a isolated neutral. I had 3 different electricians out to look at my service pannel and all 3 said it was wired correctly. I asked what they would do differently in a new house they said nothing. 2 black wires each go to a circuit breaker, bare wire goes to grounding bus bar, and neutral (white) goes to the same grounding bus bar. Are all 3 electricians wrong or is the appliance maintenance guy wrong? The appliance is manufactured with a white neutral power supply and a frame connected copper wire.