hardwiring skutt 1027

[myrtle]

Hi folks,  I'm looking for some hardwiring advice. Here is my situation: 

I just bought a skutt 1027 Kiln master. It is going in a shed out back. The shed has a subpanel with a designated 60 amp breaker for the kiln. I am going to need to hardwire the kiln because it comes with a 50 amp plug which isn't compatible with the recommended 60 amp breaker. I've ordered a Siemens 60 amp switch that was recommended by Skutt's tech support.

My question is has anyone on here DIYed hardwiring their kiln to the shut off box from the breaker? Do you have any good resources or recommendations? 

Here is the switch box i'll be working with:  https://www.lowes.ca/product/circuit-breakers/siemens-60-amp-2-pole-240-volt-non-fusible-siemens-switch-40740?&cm_mmc=shopping_google-_-6444651998-_-76957851997-_-pla-853640439311&gclid=Cj0KCQjw6sHzBRCbARIsAF8FMpXxFapizDYeU_O582gNnXT_JpwLWTOXd9HgkokqV7ad8TwZDNbMvCgaAj9REALw_wcB&gclsrc=aw.ds 

[ronfire]

I like the hard wire setup better as there is less connections and plugs can give problems over time. Mine is wired direct to the breaker with no cutoff switch the panel is only 15' away.

 

[Bill Kielb]

1 hour ago, myrtle said:

Hi folks,  I'm looking for some hardwiring advice. Here is my situation: 

I just bought a skutt 1027 Kiln master. It is going in a shed out back. The shed has a subpanel with a designated 60 amp breaker for the kiln. I am going to need to hardwire the kiln because it comes with a 50 amp plug which isn't compatible with the recommended 60 amp breaker. I've ordered a Siemens 60 amp switch that was recommended by Skutt's tech support.

My question is has anyone on here DIYed hardwiring their kiln to the shut off box from the breaker? Do you have any good resources or recommendations? 

Here is the switch box i'll be working with:  https://www.lowes.ca/product/circuit-breakers/siemens-60-amp-2-pole-240-volt-non-fusible-siemens-switch-40740?&cm_mmc=shopping_google-_-6444651998-_-76957851997-_-pla-853640439311&gclid=Cj0KCQjw6sHzBRCbARIsAF8FMpXxFapizDYeU_O582gNnXT_JpwLWTOXd9HgkokqV7ad8TwZDNbMvCgaAj9REALw_wcB&gclsrc=aw.ds 

Since you have the two pole disconnect I would suggest you install it within easy reach. It is made for isolating your kiln while technically the breaker is made to safeguard your kiln, not necessarily be a switch.  Most codes mandate the disconnect be within six feet for  easy service access and often assists with fire fighting efforts.  As far as wiring you will run pipe and wired from your sub panel to the switch and likely greenfield would be easiest from the switch to the kiln using the appropriate wire, conduit and matching connectors and wire terminations.

I would not skimp or improvise on any of the above and ensure ALL connections are mechanically tight. Done this way it should last a long, long time. 

To answer your question I have diyed many including much larger loads and most of the resources are available at most big box stores. Look at your disconnect and you should find two terminals marked LIne1, Line2 ( most often on top) and two terminals marked load1, load 2 (usually on bottom) connect all neatly and tightly. Leave some room for a neat wire work loop in each, no need to cut wires crazy short.

Just to add, you likely can use the plug but since you have the switch and it’s in an outside environment, hardwire it. The kiln probably specifies a 50 amp plug but the use says you need a sixty amp breaker. This is to actually protect the breaker more so. Purely resistive loads that can operate continuously at full load for more than a prescribed time limit require a breaker rated 125% of the load per code.

[neilestrick]

The kiln only pulls 48 amps, so the 50 amp cord is adequate. Plus the cord has #6 wire which can handle 60 amps. The kiln is UL rated for use with that cord, on a 60 amp breaker. If the cord was not appropriate for use with a 60 amp breaker then no one would be able to use it.

[myrtle]

4 minutes ago, neilestrick said:

The kiln only pulls 48 amps, so the 50 amp cord is adequate. Plus the cord has #6 wire which can handle 60 amps. The kiln is UL rated for use with that cord, on a 60 amp breaker. If the cord was not appropriate for use with a 60 amp breaker then no one would be able to use it.

I'm confident in the cord but the plug that comes attached to it is only 50 amp  and I was told by skutt support that if I wanted to plug the kiln into the wall instead of hardwiring, I'd need to upgrade the plug to a 60 amp plug which is industrial and costly. So instead I disconnected the plug in order to hardwire the cord from the kiln into the shutoff switch. 

[Bill Kielb]

2 hours ago, myrtle said:

I'm confident in the cord but the plug that comes attached to it is only 50 amp  and I was told by skutt support that if I wanted to plug the kiln into the wall instead of hardwiring, I'd need to upgrade the plug to a 60 amp plug which is industrial and costly. So instead I disconnected the plug in order to hardwire the cord from the kiln into the shutoff switch. 

The spec on the Skutt kiln calls fora 50 amp receptacle which gets a 50 amp plug. So again, technically you can use the plug but the manual also says disconnect the kiln before you open it. I doubt seriously if you will unplug the kiln every time you load and unload  and even if you did the plug would wear out. You have the disconnect coming, use it. The finer points of why it requires a 60 amp breaker has to do with how breakers function and the type of specialized load a kiln can be.

Specs: https://skutt.com/products-page/ceramic-kilns/km-1027/#specs

[neilestrick]

9 hours ago, myrtle said:

I'm confident in the cord but the plug that comes attached to it is only 50 amp  and I was told by skutt support that if I wanted to plug the kiln into the wall instead of hardwiring, I'd need to upgrade the plug to a 60 amp plug which is industrial and costly. So instead I disconnected the plug in order to hardwire the cord from the kiln into the shutoff switch. 

Skutt told you to use a 60 amp plug? That's odd, because their specs call for a NEMA 6-50 outlet and a 60 amp breaker. Every 48 amp kiln in the country is set up that way.

[myrtle]

Yes I'm finding this process and the information I'm getting from Skutt support quite confusing and rather conflicting. In spite of the specs calling for a NEMA 6-50 and the 50 amp plug that comes attached to the kilns cord, the skutt tech  specifically told me that since I have used the recommended 60 amp breaker, I would need to disconnect the plug that came with the kiln and either hardwire the kiln to a junction box or safety switch or "upgrade" the plug to to a 4 prong 60 amp plug and instal a matching 60amp NEMA receptacle.  

So, I am going to hardwire it which seems recommended, however I've run into another snag trying to instal the switch box. I purchased the Siemens 60 amp no-fuse safety switch that was recommended however the box is meant for outdoor use making installing it indoors complicated. I bought #6 copper NDM90 wire to run the 6 feet from the breaker box to the safety switch. The NDM wire will run through the wall studs, however since the box is meant to be mounted outdoors it is designed to be mounted on the outside of the wall (not set into the wall) meaning that the wire will need to run outside the wall to get into the box. 

Has anyone else used this type of disconnect switch? If so how have you installed it indoors? https://www.lowes.ca/product/circuit-breakers/siemens-60-amp-2-pole-240-volt-non-fusible-siemens-switch-40740?&cm_mmc=shopping_google-_-6444651998-_-76957851997-_-pla-853640439311&gclid=Cj0KCQjw6sHzBRCbARIsAF8FMpXxFapizDYeU_O582gNnXT_JpwLWTOXd9HgkokqV7ad8TwZDNbMvCgaAj9REALw_wcB&gclsrc=aw.ds

 

 

[Mark C.]

I have a knife switch box mounted outside that controls my 90 amp underground shop service . It mounted near my 200 amp panel outside on the wall behine a custom cover that covers aall sevice boxes. That switch is beyound my 90 amp breaker so power leaves breaker to knife switch then on tyo underground  contuit to shop sub panel. Then another wire goes to  another subpanel where my electrics are wired to .There is two breakers between -each in a thoise panels. 60 amp breaker for 48 amp skutt 1227-all #6 copper wire. The knife switch  for me isolated my shop when my generator kicks in and the transfer switch cuts off my power to shop. Taht knife switch takes the powerfrom a 90 amp direct lead to a 20 amp breaker in transfere switch-I know this sounds complicated.

You can use a knife switch for a disconnect but its not fused -you should not use a breaker as a on off switch-the knife switch is better and they are usually made to surface mount as yours is shown and are not harder to work with than flush mount-use the rear knockouts for acccess. If you are not an electrician hire one as this stuff can get you if you are green on it. The plug  and 50 amps is fine -I think that tec had it wrong.My kiln is hard wired with the original cord(50) amp for past 3 decades.(its a skutt)In that time I have cooked two 60 amp breakers (crappy square d ones )and one sub panel  connection but the cord is fine still.I rewired to Brant/eaton breakers and subpanel and had zero issues since.My power is hardwired to two kilns and if I want to work on them I have acuattly 3 braekers that control that power.I have never consider a knife switch as you are doing.No harm just a bit overkill maybe and I'm the king of overkill.

As Bill noted that switch has to be within 6 feet of said appliance (kiln) to be legal.You will fry a 50 amp breaker in no time with a 48 amp draw-they need ro be oversize to handle that load.60 amp is the correct size-your cord that cam with kiln will work just fine no matter what they said I feel. Neil summed this point up well.

[Bill Kielb]

3 hours ago, myrtle said:

Yes I'm finding this process and the information I'm getting from Skutt support quite confusing and rather conflicting. In spite of the specs calling for a NEMA 6-50 and the 50 amp plug that comes attached to the kilns cord, the skutt tech  specifically told me that since I have used the recommended 60 amp breaker, I would need to disconnect the plug that came with the kiln and either hardwire the kiln to a junction box or safety switch or "upgrade" the plug to to a 4 prong 60 amp plug and instal a matching 60amp NEMA receptacle.  

So, I am going to hardwire it which seems recommended, however I've run into another snag trying to instal the switch box. I purchased the Siemens 60 amp no-fuse safety switch that was recommended however the box is meant for outdoor use making installing it indoors complicated. I bought #6 copper NDM90 wire to run the 6 feet from the breaker box to the safety switch. The NDM wire will run through the wall studs, however since the box is meant to be mounted outdoors it is designed to be mounted on the outside of the wall (not set into the wall) meaning that the wire will need to run outside the wall to get into the box. 

Has anyone else used this type of disconnect switch? If so how have you installed it indoors? https://www.lowes.ca/product/circuit-breakers/siemens-60-amp-2-pole-240-volt-non-fusible-siemens-switch-40740?&cm_mmc=shopping_google-_-6444651998-_-76957851997-_-pla-853640439311&gclid=Cj0KCQjw6sHzBRCbARIsAF8FMpXxFapizDYeU_O582gNnXT_JpwLWTOXd9HgkokqV7ad8TwZDNbMvCgaAj9REALw_wcB&gclsrc=aw.ds

 

 

Yes, knockouts are on the bottom and also  generally can  be rear fed. You can hole saw or step drill your own but only in an unobstructed area  of the switch as there is limited space to do this.

The sixty amp breaker is upsized because of the type of load. The machine is rated 48 amps so the 50 amp plug and receptacle are fine. It’s a code thing to protect the breaker from overheating during normal operation. If a purely resistive load (and that is what the kiln is)  and it is possible for it to run at full load for a certain amount of time then code requires  the breaker be rated 125% of the load to keep it from overheating. 

I assume the NDM is roamex or equivalent (And allowed for your location) so you will need to familiarize yourself with roamex connectors and use of non metallic cable and proper entrance into boxes. Your switch is metallic so you will need to bind the box to your ground and also run that ground to your kiln. Acceptable ways to do this require that you bond a bare copper wire to the box using the ground screw and mechanically twist all three together ( bond wire, ground from the electric source and ground wire to the kiln) neatly and tightly. Finish this connection with a wire nut. If an inspector sees just a wire nut and not a decent mechanical twist he would fail this connection.

when in doubt, this is pretty simple for a licensed electrician.

[myrtle]

Thanks for all the great info folks.

Bill - see attached pic.  This is what came with the switch.  Can I just use this to ground the switch instead of your method?

There is one knock out in the back of the switch, not two.  I can use this knock out for the NMD90 #6 Cu (yes this is Loomex) and it will meet spec because the cable will only be travelling through the wall to the sub-panel.  And yes, I have two 3/4" connectors for the NMD90 cable - one for the switch, the other for the sub-panel.

The switch is less than 6' from kiln - no prob there.

My last head scratcher is how the wire from the kiln should run to the box.  Does it need to travel through conduit?  Or can it travel freely from the kiln to the wall, and run up the wall using fasteners to secure it?  That's how the Skutt kiln at our town's pottery guild is wired.  They did have an electrician install it, but I'm just trying to cover all the bases here.   Am I missing something?  

Not too impressed with the wild goose chase the Skutt tech sent me on...

[Mark C.]

That can be your ground connector for box and kiln just hook the incoming and outgoing grounds and bond the box with the screw,and you can use a wire clamp that grips the kiln flex cable -it slips into a knockout. You may have to upsize the knockout with a step drill to accommodate a larger cord. 3/4 may not be big enough .Hopefuly there is a 1 inch knockout if not make one by up- sizing with step drill. You need a little wire covering to protude into the box (I'm speaking about the flex cord from kiln). She conductive grease the wire ends to prevent oxidation and tightened to specs-as this is the important part as most do not tighten enough and that over the long haul makes for heat and bad issues.

[Bill Kielb]

9 hours ago, myrtle said:

Thanks for all the great info folks.

Bill - see attached pic.  This is what came with the switch.  Can I just use this to ground the switch instead of your method?

There is one knock out in the back of the switch, not two.  I can use this knock out for the NMD90 #6 Cu (yes this is Loomex) and it will meet spec because the cable will only be travelling through the wall to the sub-panel.  And yes, I have two 3/4" connectors for the NMD90 cable - one for the switch, the other for the sub-panel.

The switch is less than 6' from kiln - no prob there.

My last head scratcher is how the wire from the kiln should run to the box.  Does it need to travel through conduit?  Or can it travel freely from the kiln to the wall, and run up the wall using fasteners to secure it?  That's how the Skutt kiln at our town's pottery guild is wired.  They did have an electrician install it, but I'm just trying to cover all the bases here.   Am I missing something?  

Not too impressed with the wild goose chase the Skutt tech sent me on...

If your studio is wired with the roamex in the wall then likely your area of the country allows non metallic sheathed cable. I am familiar with three types or Non Metallic sheathed cable: NM -B non metallic interior wiring, UF-B Underground feeder for direct burial, and SE or service entrance. Loomex is Canadian and so is the NM-D designation, interesting! So you are in Canada. Generally US and Canadian wiring practices are similar but it’s always good to know and understand your codes. 

In general the 2- #6  cable will fit in a 3/4” NM connector so your wire runs from the service panel inside the wall cavity and into the back of your disconnect using appropriate connectors at the service panel and back of the new disconnect. The ground bus pictured above gets bolted to the inside back of the disconnect switch and allows the bare ground wire to be terminated (bonded)  there and also the kiln ground wire to be terminated there. In this case you do not need a special pigtail arraignment.  All these connections must be tightened securely they protect from electric shock.

Your kiln cord will enter into  the bottom through an appropriate cord grip connector.  You will need to terminate all these wires appropriately in the disconnect switch. The cord grip connector might require a 1” knockout To fit your cord hopefully this is present in the bottom knock outs of the disconnect switch, else you will need to enlarge it. As far as running roamex or NM-B cable on the surface it is generally not allowed and is for protected in wall wiring only.

even though this seems like simple stuff it’s not, you may really want to have a local  electrician do this appropriately in accordance with local code.

 

[neilestrick]

Based on all your questions, it sounds like you don't have a lot of experience with running electrical lines. At the very least you should have your work inspected when you're done, or it may be worth brining in an electrician to do the work.

16 hours ago, myrtle said:

Yes I'm finding this process and the information I'm getting from Skutt support quite confusing and rather conflicting. In spite of the specs calling for a NEMA 6-50 and the 50 amp plug that comes attached to the kilns cord, the skutt tech  specifically told me that since I have used the recommended 60 amp breaker, I would need to disconnect the plug that came with the kiln and either hardwire the kiln to a junction box or safety switch or "upgrade" the plug to to a 4 prong 60 amp plug and instal a matching 60amp NEMA receptacle.  

This doesn't make sense. The 6-50 is a single phase 3 prong plug- two hots and a ground. Why would you switch to a 4 wire 60 amp plug? What's the 4th wire for? Are you sure you were talking to someone at Skutt, and not some distributor?

[Mark C.]

Neil are the newer kilns running a neutral and two hots and a ground these days? Back in the day all kilns seem to have two hots and a ground. I'm guessing  newer kilns are for some reason  (maybe the controller? ) runing a neutral for a 110 circuit?

 

[myrtle]

Hi Neil, 

You are correct in assuming I'm a novice. I will be having the work checked over to make sure it is all proper before firing. 

I have been speaking with /emailing  Skutt technical support. Here is a copy and paste straight from the tech support email regarding the plug and breaker:

"Because of the way the national electrical code is written, if you put the kiln on a 60 amp breaker instead of a 50 amp breaker, you are then required to remove the 50 amp plug on the kiln and either hardwire the kiln power cord to a junction box or disconnect switch, or acquire a special 60 amp plug to put on the kiln power cord. The 60 amp plug is only available in an expensive special industrial version (NEMA 14-60) that would have to be special ordered through an electrical supplier, and it requires a 4-wire hook-up that’s includes a "neutral" wire in the building circuit. If you switch to the NEMA 14-60 plug, the electrician would have to include the extra "neutral" wire in the building circuit so that the wall receptacle has all four wires connected to it to meet code."
 

15 hours ago, Bill Kielb said:

If your studio is wired with the roamex in the wall then likely your area of the country allows non metallic sheathed cable. I am familiar with three types or Non Metallic sheathed cable: NM -B non metallic interior wiring, UF-B Underground feeder for direct burial, and SE or service entrance. Loomex is Canadian and so is the NM-D designation, interesting! So you are in Canada. Generally US and Canadian wiring practices are similar but it’s always good to know and understand your codes. 

In general the 2- #6  cable will fit in a 3/4” NM connector so your wire runs from the service panel inside the wall cavity and into the back of your disconnect using appropriate connectors at the service panel and back of the new disconnect. The ground bus pictured above gets bolted to the inside back of the disconnect switch and allows the bare ground wire to be terminated (bonded)  there and also the kiln ground wire to be terminated there. In this case you do not need a special pigtail arraignment.  All these connections must be tightened securely they protect from electric shock.

Your kiln cord will enter into  the bottom through an appropriate cord grip connector.  You will need to terminate all these wires appropriately in the disconnect switch. The cord grip connector might require a 1” knockout To fit your cord hopefully this is present in the bottom knock outs of the disconnect switch, else you will need to enlarge it. As far as running roamex or NM-B cable on the surface it is generally not allowed and is for protected in wall wiring only.

even though this seems like simple stuff it’s not, you may really want to have a local  electrician do this appropriately in accordance with local code.

 

Thanks Bill, this is all very helpful information! Yep I'm in BC Canada. I didn't realize that the NM-D was Canada specific- good to know! 

[Bill Kielb]

42 minutes ago, myrtle said:

Hi Neil, 

You are correct in assuming I'm a novice. I will be having the work checked over to make sure it is all proper before firing. 

I have been speaking with /emailing  Skutt technical support. Here is a copy and paste straight from the tech support email regarding the plug and breaker:

"Because of the way the national electrical code is written, if you put the kiln on a 60 amp breaker instead of a 50 amp breaker, you are then required to remove the 50 amp plug on the kiln and either hardwire the kiln power cord to a junction box or disconnect switch, or acquire a special 60 amp plug to put on the kiln power cord. The 60 amp plug is only available in an expensive special industrial version (NEMA 14-60) that would have to be special ordered through an electrical supplier, and it requires a 4-wire hook-up that’s includes a "neutral" wire in the building circuit. If you switch to the NEMA 14-60 plug, the electrician would have to include the extra "neutral" wire in the building circuit so that the wall receptacle has all four wires connected to it to meet code."
 

Thanks Bill, this is all very helpful information! Yep I'm in BC Canada. I didn't realize that the NM-D was Canada specific- good to know! 

Wow, been a long time since I was a practicing electrician but saying you would need to run a neutral to fill an empty slot in the cord end seems to stretch things a bit. Interesting if true, what do I do with the extra slot in the receptacle end run a full sized neutral wire connected to nothing in the kiln? This seems very questionable and in my view disappointing actually.  He needs to answer the question of why the machine specification (company specification) calls for a 50 amp receptacle and was engineered and UL or in your case CSA  certified as such.  Seems poor IMO, sorry you got stuck with this tech. Just my opinion though.

#6 NM-B  (or likely NM-D as well) wire BTW is  generally rated for 55 amps because it is  generally 60C insulation. It’s  often rated lower than #6 wires in conduit because it will heat up more just because it’s cable and the wires are bundled close to each other..  Just sayin! Best to confirm everything with a local electrician. I think you are on the right track now with what you purchased.

[Mark C.]

I just hardwired to a junction box (cut the plug or take it apart) as noted in his reply (you are then required to remove the 50 amp plug on the kiln and either hardwire the kiln power cord to a junction box or disconnect switch)and its worked for decades.

That junction box is on a piece of metal flex  coming from my sub panel.The J box is a 4 square deep with metal cover.I just undid it when rebuilding the kiln in these  photos.You can view that box in five photos up from the last photo-I just did this a few months ago.The rebuild that is.

https://community.ceramicartsdaily.org/topic/21326-skutt-1227-rebuild/?tab=comments#comment-171678

As to Canadian Electrical regs well you are on your own eh.

 

[Stephen]

On 3/18/2020 at 12:05 AM, myrtle said:

I'm

nevermind, didnt get the reg.

[Sorcery]

On 3/27/2020 at 9:33 PM, Bill Kielb said:

Seems poor IMO, sorry you got stuck with this tech. Just my opinion though.

At first I thought either @myrtle simply jumped up a line on the chart, to a larger kiln, to get this 60 amp information. Or that the tech had the wrong kiln in mind.

Now it sounds like @myrtlementioned 60amp, perhaps accidentally?, And the tech just began spouting written information,  instead of thinking, "hey, this is the wrong number....".

Something seems off.

I'd double check all the info with the (other) tech.

Best.

 

Sorce

[myrtle]

Hey all, Thanks for all the information and suggestions. You guys got me on the right track and I think I've finally gotten to the bottom of most of my questions! 

Bill, after a fair bit of digging (and phoning a local electrician ) I finally figured out that my NMD wire has an allowable ampacity of 65amps.  The NMD wire has a 90C rating, but in accordance with recently updated Canadian code, it gets de-rated based on the terminal rating on the equipment it is getting connected to. My switch box has a rating of 75C and NMD wire at 75C has an ampacity of  65  (knocked down from 75 amp rating at 90C) so I'm good to go with the materials I have. This project has been quite an education! 

Mark, that looks like a beautiful rebuild! 

One final question: Anybody have any tips about stripping the Skutt kiln cord?  The sheath / insulation is pretty darn tough, although it has some flex.  I don't have special electrician tools.  I'm guessing just go carefully with a blade?  I'm sorry if these seems like a dumb question! 

 

 

[Bill Kielb]

6 minutes ago, myrtle said:

Hey all, Thanks for all the information and suggestions. You guys got me on the right track and I think I've finally gotten to the bottom of most of my questions! 

Bill, after a fair bit of digging (and phoning a local electrician ) I finally figured out that my NMD wire has an allowable ampacity of 65amps.  The NMD wire has a 90C rating, but in accordance with recently updated Canadian code, it gets de-rated based on the terminal rating on the equipment it is getting connected to. My switch box has a rating of 75C and NMD wire at 75C has an ampacity of  65  (knocked down from 75 amp rating at 90C) so I'm good to go with the materials I have. This project has been quite an education! 

Mark, that looks like a beautiful rebuild! 

One final question: Anybody have any tips about stripping the Skutt kiln cord?  The sheath / insulation is pretty darn tough, although it has some flex.  I don't have special electrician tools.  I'm guessing just go carefully with a blade?  I'm sorry if these seems like a dumb question! 

 

 

Careful use of a utility blade is popular. If concerned, lots of folks will make their longitudinal cut over the green or ground. Then peal the wires away from the sheath and carefully trim the sheath away from the wires.

[Mark C.]

Yes be very careful . on that outer sheath a sharp untidily blade is good. Do not nick the other wire insulations. also when stripping those wire do not nick that wire either. Sharp tool is best but slow controlled cuts are best