The electric cooktop up and dies (20+ years old, can’t really complain), so we picked up a new one. When I went to install it, I found something in th instructions confusing. If anyone really wants to see the manual, it is here:
On page 4, it states that it muzt be installed into a 3-wire setup, and basically instructs to cap off the service side white (return) if you have a 4-wire setup. I do have a 4-wire, and the existing cooktop is just what I would expect: red>red, blk>blk, bare gnd from appliance > green from service, and the white from the service is capped off, just like the manual for the new one.
HOWEVER, the actual new appliance has a white and ground (grn) wire in addition to the black and red, but they are tire-wrapped together. In the manual it states that the appliance does not have a white neutral.
I assume that they want me to connect the tie-wrapped white and green on the appliance to the ground on the service, but what is bugging the hell out of me is that there are 4 wires from the unit, one IS white, and if you want me to treat those two tie-wrapped wires as one, then you should say so, instead of pretending that they are one!
I know that’s a bit of a rant, but I just want confirmation that I should be conneecting the tie wrapped wires as if they were one wire.
What I don’t understand is how this is legal- I thought you were not supposed to use the ground as a return on 220 setups any more. I know it was common once, but this thing is brand new.
away from where the neutral wire is grounded (at your meter or circuit breaker box) you want to treat the neutral and ground wires as not the same.
it is not unusual for products not to match the manuals. the manuals are printed thousands at a time. if the product changes from the manual then they should include a sheet(s) of what the changes are.
call the customer service number and ask for clarification.
you do not want to operate a cooktop without having its grounding wire (GRN) connected to your grounding conductor (GRN).
In a four-wire setup, you have two hots (between them is 240v) and a neutral (120v between it and either hot) and a safety ground. Appliances which use a four-wire setup will use the two hots for the heating element (or whatever) and one of the hots plus the neutral for the control electronics or whatever stuff works on 120v.
IF the appliance does not have a need for a 120v source, then it only needs the two hots and a ground. There is no need for a neutral. So in that case you’d want to cap off the neutral wire and connect the two hots and the ground.
I am assuming that the new appliance has no need for a neutral but included the wire anyway for mysterious reasons. While it would theoretically be OK to connect an unused white wire to ground, it is (IMHO) bad practice to do so, and it might be against code. I would instead connect the four wires to the service in the usual way. If the appliance is not actually using the neutral, no big deal.
Johnpost: The proposed connection would not have no ground, but rather no return, using the ground for that pupose instead. Still not what I always thought was corret, but apparently OK. I know that my well uses two hots and a ground, but as I said, I always believed this to be an older approach no longer considered kosher. From what Friedo says, it seems I was wrong.
Zenbean:I tink you are reading the diagram backwards- figure 5 shows Red, Black, Green, and White from the service, with the white capped. It shows only red, black, and green from the appliance, all connected to their service counterpart. And that’s all fine, I get that, but it ignores the fact that the green from the appliance is paired with a white from the appliance. So my big issue is that in not acknowledging that fact, I hate to assume that they are to be treated as a single connector. And for that reason, from a manufacturing perspective, why two wires?
Friedo, that all makes sense. And this particular model doesn’t have anything that would obviously need 120. The only function besides the burners are indicator lamps, and those are probably either 220 or stepped down somehow. I read somewhere that manufacturers have realized that by designing the other components to run on 220, they can save mfg costs.
That manual, while nearly identical to the one that came with my unit, has a different rev date (0904) than mine (0901), and the diagram is different. AND, the unit has a mfg date of 07 2011, which is well after the dates on the manual.
I don’t find this acceptable at all. I searched for the manual on line so that I could share a link, looked quickly to make sure it was the right one…
Thanks everyone. All installed and working properly.
First, I was irritated and annoyed that my unit did not come with the correct instructions. But get this:
The instructions say to leave the unit in its styrofoam protectors until ready to drop it in. I did this.
When I finally took it out, there was a tag affixed to the bottom showing proper 4-wire installation. That tag was dated 2009. So, 15 years after code updated to prohibit grounding through neutral (with old circuits grandfathered), they updated the design but continue to ship with a manual that explicitly states the unit does not have a neutral, and which is dated 11 years ago.
Seems to me that someone is going to have a fire or get a shock, and Sears (Kenmore) will have at least some liability for really confusing documentation.