In the next few days (like before Christmas dinner…) I’ll be wiring up a 7.2kW (30A @220). I’ll be using 8/3 on a 40A breaker, but question is do I put a plug on the end of the oven whip and a receptacle in a 4 11/16″ metal box or just put the whip into the 4″ metal box, hardwire and put a blank plate on it? Reason I ask is that I didn’t readily find a 40A plug and 40A receptacle or a plate to a metal box that appeared to be for this application (at Lowe’s which typically has a pretty solid electrical department).
MERC.
Replies
My electrician wired a big double electric oven a couple of months ago (I did the cabinet modification) and hard-wired it. Makes sense to me. These appliances don't get moved very often.
Did installation instructions come with the unit?
Al Mollitor, Sharon MA
The ones I've always seen were with a receptical. you can work on the stove then.
Avoid the plug.
Install a flex connector at the end of the existing whip and run it into the side of a 4" square box. Make up the connections in a 'workmanlike manner' with good quality wire nuts and install a blank plate. Slide the oven back into place and enjoy the rest of your Christmas.
Trick is to surface mount the 4" junction box in a location that allows the oven to fit in and allows the existing flex whip to be long enough to allow access to the box. Mostly I get a helper to hold the oven, resting a corner on the shelf where the oven would normally be or I arrange for support, a chair or two usually works, if I'm alone.
Where there is a open cabinet or drawer below the oven I sometimes drill a hole in the oven enclosure bottom to snake my whip through and set my junction box below it. It allows me to make up my connections while the oven is in place. Simple.
Plugs are always a weak point. I trust a properly made connection much more. In the many ovens I have installed the only ones I can ever remember installing on a plug were some commercial units and that only because the specs required I do it that way.
Stoves, self contained cook-top and oven units that sit on the floor, mostly get plugs. They are normally fed by way of a rubber cord not a length of flex and only rarely have I seen one in a situation where you could make the required hard wire connections without standing on your head.
Not sure of the logic in running a 50A unit on a plug and a 30A unit hardwired but that is just the way it is, has been, done.
Edited to add last two blocks.
Edited 12/21/2004 8:25 pm ET by 4LORN1
Thanks for the quick response. I was hoping to go with the hardwire. It just seemed more right to me and think you put it into words by calling the plug a weak point. No sense in plugging a 300 lb oven.
Fortunately this oven is just being hacked temporarily into my existing kitchen while I build the next kitchen. So wiring will be quite easy since it isn't finished. But I do, fof course, want it to be safe.
MERC.
I just finished a commercial kitchen that the owners wanted the double convection oven,2 burner top,griddle,fryer all plug and receptcle connected it reallly,really sucked especially the 100amp3phase grill. Hard wire that sucker!
How come the owners wanted such a thing plugged? Are they not convinced of their longevity as a business?
MERC
The pitch the owners gave was for ease of cleaning the hood and equipment....the 100amp pin & sleeve connector takes three men and a boy to disconnect, it looks like a coffee can hanging out of the wall. The customer is always right....
Re: "The customer is always right...."My usual method of handling such 'innovations' is to compliment the customer on their wise choice. That is just before I mention that most restaurant owners balk at such extra costs...Give it a few seconds to sink in.When they ask about these extra costs, and they always seem to eventually ask, I rattle off the cost of a commercial three phase receptacle and cord cap, don't forget to add the normal mark up - 100% in this area - .After the soda shoots out both nostrils. I calmly ask why they want the unit connected by plug. When they tell me it is so the unit can be moved for cleaning I mention that perhaps, for a fraction of the cost of the receptacle and plug, I could install an extra-long whip that will give her plenty of room to scrub behind the unit.
When I mention the cost, in comparison to the alternative, they usually go for it. Saves a lot of trouble.Trick is try to make it seem to be their idea. Some electricians see restaurant renovations and new construction several times a year. On the other hand the up and coming restaurant owner might only see a couple in his/her life. It is their baby. A special thing where their dreams will play out. They want it perfect. They don't understand that theirs is not the first restaurant ever built and that the wheel has already been invented. That in 99.9% of the cases a hard wired whip is the most practical solution. Allowing them to 'discover' this on their own just makes everyone a little happier in the long run.
Ah,you make it all seem so came and reasonable, I shall adopt this yoda-like demeanour on my very nexy hysterical 5' tall asian restauranteer. When I get excited some form of spanglish sprouts forth. Mixed with his thailish, the owner of our company's womanish, ahj's whyish I gave up ... but I will use the 4lorni-ish the very next time,thanks.
When the stance works you, sometimes even I, come off like a wizened construction hand dealing at a stroke with myriad issues presented by an impatient, short sighted and egotistical owner. Yes, oh owner of the future Grasshopper restaurant take the perfect vision from my hand. Let it be so as I steer them past the rocks of their infantile passions. Big ego boost when it works that way. Prepare for bipolar hero/goat mode.Of course that way, and others, were created in response to a series of train wrecks. Not to say that a good train wreck does not have its finer points. The married co-owners going bonkers. Him alternating between visions of the super kitchen and bankrupted despare, disgrace and open crying in the back room. Both bipolar extremes lubricated by a smooth sheen of scotch.She showing up in manic mid-rant contradicting everything he had said and then, losing steam, seeking solace in wine and my helps young, firm arms. At least once she retreats to the previously mentioned back room with him. Hard enough to get any work out of the guy without his hands being inside her blouse. I used to think if you presented a professional demeanor and clearly stated how you saw it it would magically work out by way of reason and good will. Nope. Never, not once did it work that way. People don't want simple and straightforward. They want psychodrama. They have to be engaged. They need a framework so they can play out their feelings about the job, their baby. The owners have to be managed just like your help and your suppliers. But more so. My help just does their thing for eight or ten hours then its their time.Up and coming restaurant owners are making a twenty hour a day commitment with their last remaining dollars. They are steering themselves into a swirling one-way toilet bowl of long hours, exhausting work, passion, debt, employee relations and fickle public reaction that terminates in a knothole. Something like 90% of all restaurants close in the first year. Of those that make it one year another 80% or so won't make it to two years. No wonder that at least one passionate yelling match on site is the norm. That divorces are expected. Hurt feelings and raw nerves are all part of the game.After a few train wrecks, or near train wrecks, anyone who regularly helps assemble restaurants, or homes but they are less emotional, has to develop a 'patter' or persona, a manner of gently guiding the owners through this. Another electrician who I work with has a 'Colombo' routine. Owner comes in and demands at the top of his lungs that the appliance have to go over 'there'. Plans and conduits already run say otherwise. He breaks out a 'Well of course. Anyone with half a mind could see that they are much better where you say. I'll get right on it. Very good.' The new owner is placated. He/she just really wanted to feel the comfort of being in charge and listened to.Once they have cooled he breaks out the 'You know I don't know much about restaurants and making food so maybe you could straighten this minor point out for me... ' Then in a series of non-threatening questions he allows the owner to see the appliances were planned to be in the right spot all along.A created persona is a handle that the client can grab onto. Easier for them and easier on you. It protects both sides. If you go in with illusions that being 'genuine' with you heart on you sleeve is the way to go your going to get your feeling hurt. A persona allows you to calmly deal with a customer who, not realizing the seriousness of the charge, accuses you of not knowing your job. Of being incompetent. It happens. Usually at high volume with everything hanging out. 'What do you mean you can't read my mind and work for free?'A 'Yoda' or 'Colombo' persona lets you take the attack and put it in perspective. It gets your ego out of the way. It keeps you on the job. Working, doing what you do as best you can, in the charged minefield of a new restaurant owners hopes, dreams and mounting debt. No need to walk off. No need to counter-attack. You, I, stay slightly detached while remaining engaged, effective.Almost every time the owner makes dire threats and tosses insults they make it known they don't mean it. They are projecting the pressures they are under. Once the job is over and they can bask in a new, well designed and planned, restaurant they calm down and count their blessings. You and they know you saved them money and they got more restaurant than they paid for. Often you have a friend for many years after. Their positive opinion reinforced by their horrible, but understandable, behavior previously.
That is a really nice piece of thread which I've cut and pasted into Word, printed and will be installed next to the job board at work. I can't guarantee anyone else will read it because I'm not actually sure anyone else can read there, but it is superb.
Down to the local AHJ, usually. Houston wants an armored "rat tail," but the inspectors don't seem to care whether it's flex conduit or MC, as long as the wire size is right (and you use four wires for the hook up).
Other places differ--I've seen flex trailing into an open box; I've also seen an "outdoor" box used so as to thread the flex connector on.
I do know that, most of the time, there's just enough slack to make up the connection--if you happen to have a stout, young, strong, helper to hold the wall oven unit just tipped into the cabinetry.
Sure would be nice if they'd make the connection something you could make up, say, behind the control panel--rather like moden DW do.
Yes I agree they don't make it easy on the installer. My Over (Jenn Air) has a fairly long whip, long enough to drop it through the floor into the basement ceiling. I'll either put it there or in the small cabinet immediately below the oven.
MERC
they don't make it easy on the installer
My fave is when the City require the whip to be removed, and then put back again by a licensed electrician.
But that's just part of the Joy of Building . . . <g>Occupational hazard of my occupation not being around (sorry Bubba)