Thanks ahead of time... I live in a home built in 1981 and the electrical wiring to the old
Top range consists of three wires ( black, white and a copper bare wire). I bought a new
Electric range that has connections in the back for four wires. My questions are:
1. do I purchase a three plug outlet for the new range?
2. do I use the copper wire for the ground wire (in the middle)?
3. will I leave the green screw on the range alone (no wire connection)
4. a schematic or picture would surely speak a thousand words
5. is 50 amps enough for the outlet and cord?

My answers in bold:

1. do I purchase a three plug outlet for the new range?
Yes

2. do I use the copper wire for the ground wire (in the middle)?
Yes, the bare wire will act as the neutral and equipment ground, and will connect to center silver terminal.

3. will I leave the green screw on the range alone (no wire connection)
No, there needs to be a jumper from the neutral connection to the green screw.


4. a schematic or picture would surely speak a thousand words
Sorry

5. is 50 amps enough for the outlet and cord?
No more than 50 amps, if the wire is #6, and a 40 amp breaker if wire is #8.

This practice, while no longer allowed for NEW installations, was done for many years with no problems. If the 3 wire cable is in place, it is allowed to be used, by the NEC.

No existing installation is mandated to be upgraded to meet the code in effect, only to meet the code that was in effect at the time of construction.

I can't say for Canada. Best to check your local code anyway, as I always suggest.

Have to agree with tk, Where I live, 4 wire dryer and range connections are for New and Remodel.
I also wonder why it took so long to stop stealing neutral from ground, Just been luck, never had problem or shock because of 3 wire.

Since you imply that people could be severely injured by existing appliances wired with the neutral and equipment ground as one common wire, could you explain exactly the details of how this could occur?

Describe the path the current will take to cause a shock.

Are there any statistics on injuries caused by this wiring method?

Keep in mind that the 4 wire circuit was implemented by the NFPA NEC in 1996, and before then, nearly every electric range and dryer in the USA was wired using the three wire method.

If anyone ever was hurt by this arrangement,or if the likelihood of existing installations being a possible hazard, there should be more of a concerted effort to have this wiring method removed and replaced for the millions of existing appliances.

Hospitals should be over run with injuries and fatalities, and only in the USA.

Has Canada always used the 4 wire method? If not, have they implemented a country wide plan to eradicate the 3 wire appliance circuits?

Bhayne, while expert opinion is always welcomed, the offering of statements that at least your child won't be injured, without factual backup to laypeople is similar to yelling "Fire" in a crowed theater.