Microwave outlet replacement

[tdf-texas]

Originally Posted by John in Santa Cruz

not sure I understand why that other wire goes to the wire nut, and not just directly to the breaker.

Wire nuts are legal to use in a breaker panel unless the fill exceeds 75% .
https://diy.stackexchange.com/questi...google_rich_qa
Doing a double-tap (two wires on a single breaker terminal) is not legal unless the breaker is designated by the manufacturer that it can be used as such.

[Brian B-P]

Originally Posted by MikeS

I don't understand how the microwave must be on a dedicated circuit, yet we keep seeing examples of it not including the above linked thread? Maybe my definition of dedicated is not the same as electrical code.

There is not just one single electrical code. There are national codes, provincial and state codes, and industry-specific rules.

For an RV built in Canada, design and construction requirements are established by CSA standard Z240, which largely refers to other standards for details. The section for electrical wiring (other than the 12 volt DC stuff) is Z240.6.2-14, and it refers to the Canadian Electrical Code (C22.1-15 and C22.2). In a quick reading, I don't see any requirement for the microwave receptacle to be on its own circuit, since it does not exceed 12 amps or 1500 watts... but I'm not an electrician or electrical engineer.

Anyone can view CSA Z240 RV, but you need to create a (free) account in CSA Communities... then read the Z240 RV Series 14 document.

[sclifrickson]

Originally Posted by tdf-texas

A 950 watt microwave pulls about about 1200 watts or 10 amps. The WF-8955 converter pulls about 7.8 amps under full load. Guess what problem can occur if both are powered by a 15 amp breaker. That's one of the reasons a microwave is required by code to be on a dedicated circuit. Dedicated means that no other device is on that circuit.



Escape is not following NEC code by wiring these circuits like this. Oh, and putting two wires on a single breaker terminal will get you flagged for a violation on an electrical inspection.

Do RV’s fall under those particular codes or are those permanent-structure codes? I ask because I am not an electrician, but do know that the rules are different. Also, I find it hard to believe that Escape is not following *all* the required codes. They are quite particular about such things.

[MikeS]

Originally Posted by Brian B-P

There is not just one single electrical code. There are national codes, provincial and state codes, and industry-specific rules.

For an RV built in Canada, design and construction requirements are established by CSA standard Z240, which largely refers to other standards for details. The section for electrical wiring (other than the 12 volt DC stuff) is Z240.6.2-14, and it refers to the Canadian Electrical Code (C22.1-15 and C22.2). In a quick reading, I don't see any requirement for the microwave receptacle to be on its own circuit, since it does not exceed 12 amps or 1500 watts... but I'm not an electrician or electrical engineer.

Anyone can view CSA Z240 RV, but you need to create a (free) account in CSA Communities... then read the Z240 RV Series 14 document.

I referenced code because I specifically asked if I could have an outlet inside a cabinet and I was told I could not because of code and the reason it was ok for the microwave outlet was because it was a dedicated circuit.

[Brian B-P]

Originally Posted by John in Santa Cruz

not sure I understand why that other wire goes to the wire nut, and not just directly to the breaker.

I assume that you're referring to what Ron calls the splice in the wire to the microwave, and not the pigtail arrangement used to combine wires to outlets on circuit #2. The reason for this is not entirely apparent to me, either; however, I note that the wire to the microwave is black and the wire to the breaker is grey, suggesting that they may be physically different in some way (different gauge, or the grey wire might be stranded), perhaps to work better with two conductors under one screw in the circuit breaker.

[tdf-texas]

Originally Posted by sclifrickson

Do RV’s fall under those particular codes or are those permanent-structure codes? I ask because I am not an electrician, but do know that the rules are different. Also, I find it hard to believe that Escape is not following *all* the required codes. They are quite particular about such things.

I am a retired electrical engineer who worked as a electrical safety consultant for large petrochemical plants thus explaining my familiarity with NEC code. In each of my responses, I have tried to include links to the applicable codes involved to validate my discussions.

As Brian (Brian B-P) mentioned, Escape is following the applicable Canadian electrical codes. The problem comes from the areas that Canadian code deviates from US electrical code. For those of us that own Escape trailers in the US, those variations between the two codes causes some issues. For the most part, Escape trailer wiring is within code with a few exceptions.

For example; US code requires that panelboards must follow UL Standard 67, which requires all lighting and appliance panelboards to be Class CTL. The panels and breakers used in Canada are non-CTL and are illegal for use in the US except for replacement use only in panels manufactured prior to 1965.
https://en.wikipedia.org/wiki/Circuit_total_limitation

The panel installed for the all outlets option by Escape in my trailer is a non-CTL panel with non CTL breakers. I had to special order the replacement breakers for it when I split the circuits such that each circuit had it's own dedicated breaker. Non CTL breakers are not a shelf item in the US as they not supposed to be used in installations done past 1965. I know I should have ripped out the non CTL panel and replaced it with one that meets code but at the time, I didn't feel like redoing what would be most of the wiring in the trailer.
http://www.escapeforum.org/forums/f8...ion-11047.html


I know I should be informing Rease about this stuff.

[Slickheadhunter]

Very good information here, thank you all very much!

Just got home and will be frustrating myself along with beating my head against the trailer wall for the evening! I'll let you know if I get anywhere.

[padlin]

Originally Posted by tdf-texas

Wire nuts are legal to use in a breaker panel unless the fill exceeds 75% .
https://diy.stackexchange.com/questi...google_rich_qa
Doing a double-tap (two wires on a single breaker terminal) is not legal unless the breaker is designated by the manufacturer that it can be used as such.

Interesting. My son has a few examples of the double wires on a breaker on the home he bought a year ago. The home inspector, not to be confused with the local electrical inspector, told him about it but nothing about them being illegal. I supposed there is a chance they are the ones designed for such, I'll have to look at them.

[steve dunham]

Originally Posted by tdf-texas

Wire nuts are legal to use in a breaker panel unless the fill exceeds 75% .
https://diy.stackexchange.com/questi...google_rich_qa
Doing a double-tap (two wires on a single breaker terminal) is not legal unless the breaker is designated by the manufacturer that it can be used as such.

In the area I worked in splices in panels were not allowed except in certain and limited circumstances . The local authority having juristiction interpreted the code in that breaker panels are not to be used as junction boxes .
We were not allowed to use NM so homes were wired in metallic conduit for my first 20 years in the trade .
Gray colored conductors were only used as neutrals in a 277 / 480 volt systems NEVER AS A LINE / HOT conductor
The use of half space / tandem breakers were restricted in our area long before the CTL ruling came into affect .

My point is that the NEC is a nationwide code but the local code interpretation is not .
Just because Escape doesn’t meet the NEC in every aspect does NOT mean their wiring methods are hazardous or unsafe.

[Oldtimer]

Arghhhh one more thing I’ll have to double check one does not want home away from home due to shoddy electrical when I was out in the field, what I hated the most was coming behind another electrical company that took short cuts or did shoddy work .... complete disgrace to to electrical field

[tdf-texas]

Originally Posted by steve dunham

Just because Escape doesn’t meet the NEC in every aspect does NOT mean their wiring methods are hazardous or unsafe.

I agree! The non CTL panel I referenced before is not unsafe - it only does not meet UL code. As such, if the trailer caught fire due to some problem with that panel, an insurance company covering the trailer could legally walk away without paying a penny.

[Slickheadhunter]

Well I figured it out!

On my trailer the microwave is also connected to the outside GFI outlet. The microwave wire coming out of the metal box outside outlet was rubbing on a metal screw under the seat of. The dining table and shorted out the GFI!

I moved the wire away from the metal screw and wrapped a generous portion of electrical tape around the bare spot on the wire and reset the GFI.

[Slickheadhunter]

Thanks to all who helped, it's much appreciated!

[War Eagle]

Bizarre! So the head of the metal screw in question was abrasive enough to scrape the insulation off the wire and thus exposing a hot wire?

[Slickheadhunter]

It was the body of the screw that went through the box and into the storage space under the seat.
It's a metal box that houses the outside outlet. I think I'll take a picture of it tomorrow. The wire was looped around that screw and was worn straight through to the wire.

[Eggscape]

Originally Posted by John in Santa Cruz

not sure I understand why that other wire goes to the wire nut, and not just directly to the breaker.

When I moved my panel/box a few weeks ago on my new 19 I noticed the same wirenut.
I would think if you put them side by side and screwed down the breaker screw that the screw would stop on the solid core wire and not apply enough pressure to the stranded wire that comes from the power unit allowing it to be pulled out.
If you twisted them together I think the breaker screw might shear off some of the strands as you tighten the screw against the solid core.
It is probably best if solid core wire is used for a breaker...I can see the logic when dealing with both solid and stranded wire.

[War Eagle]

A photo would be appreciated. If I understand you correctly, I'm still curious what carried enough current from the bare wire back to a ground to trip the GFI. Is the single gang metal box that is housing the GFI outlet grounded along with the outlet?

[Ron in BC]

Originally Posted by Brian B-P

In a quick reading, I don't see any requirement for the microwave receptacle to be on its own circuit, since it does not exceed 12 amps or 1500 watts... but I'm not an electrician or electrical engineer.

It was a lot of years ago when I wrote the exam, and only as part of my training, not to become an electrician, but back then the Canadian Electrical Code required a dedicated circuit for microwaves. Rule26-704(9) That was based on the general rule that all appliances, like fridges required their own circuits.

Originally Posted by Slickheadhunter

Well I figured it out!

On my trailer the microwave is also connected to the outside GFI outlet.

A good illustration of why separate circuits are good. Glad you found the problem and now some folks know more about their electrical system than they did before.

Ron

[Slickheadhunter]

I'll have to take a look at it when I take a picture.
What I do know is the wire from the microwave outlet goes into the outside outlet and was half wrapped around the back of the screw which is over an inch long protruding into the storage compartment.
I wrapped the wire generously with electrical tape and moved it away from the screw and hit the reset on the GFI and it now works.

[steve dunham]

Originally Posted by War Eagle

A photo would be appreciated. If I understand you correctly, I'm still curious what carried enough current from the bare wire back to a ground to trip the GFI. Is the single gang metal box that is housing the GFI outlet grounded along with the outlet?

The metal box is required to be grounded
The grounding of the box cannot be dependent on the device
Normally the grounding conductor in the NM cable is attached to the metal box by means of a 10 x 32 green grounding screw or a green grounding clip and then extends to the grounding screw on the device
That way if the device is removed the box is still grounded
Unless you use a self grounding device , the 6 x32 device mounting screws cannot serve as a grounding means for the device