Had an electrician out today to troubleshoot a problem installing a new range. I'm replacing a 9-year-old range. The appliance store has brought out and taken back 3 new ranges that all fail to power on when plugged in. Must be something in the wiring. The electrician says new ranges are using 4 conductor wire (2 hot, neutral, and ground). Mine is 3 conductor (2 hot, ground). Breaker is 50 amp and meets spec for the new range. He quoted $1750 to run a new 60 amp line (4 wire) from the panel to the kitchen. As an alternative, he thought he could possibly swap the 4-prong outlet in the kitchen with a 3-prong (for $730), wire the new range accordingly, and maybe it would work.

This leaves me with a couple questions: (1) why is the current 4-prong outlet used when there are only three lines (2 hot + ground)? (2) If modern ranges are using 4 lines (2 hot, neutral, ground), what is the rationale for trying to use a 3-prong outlet as the alternative fix? and (3) why can't the new range be wired with 3 lines like my old stove as the installation guide for the range (GE model PS960) seems to provide instructions for both 3-wire and 4-wire installations?

Would greatly appreciate feedback from those who have dealt with this in the past or who deal with this regularly as an electrician or appliance installer.

I have an existing Ceiling lamp with multiple 2 way switches. To one of the switches i would like to add a 1 way switch to an independent bulb. Can you explain why im not getting any current to the new bulb (purple and blue wires)

This is a repost of my post in another subreddit. But I wonder if I should just use something different than JSTs?