Older Paragon 30 amp kiln

[Snickerhaus Studio]

Hello all,

My wife currently uses an older Paragon kiln and looking at purchasing a different one in better shape. The one we are looking at is a 50 amp while the current one is a 30.  Both are close to the same age and have the P-10 kiln setter.  Question is are there multiple ways to wire these kilns so that they can run either or?  There is not enough space in our fuse panel to go to a 50 amp.  A new one would be nice but the 30 amp ones are really small.  Any advice is much appreciated.

Thanks in advance.

Wiring Misfit

[neilestrick]

@Christine Belt Welcome to the forum!

The bigger the kiln, the higher the amperage. It takes a certain amount of watts to heat up every square foot of kiln space, so more space equals more watts. Watts= amps x volts, and since the voltage is constant, you have to increase the amperage to get the watts.

When you say the fuse box can't handle the 50 amp, is that because you don't have space in the kiln for any more breakers, or because you've maxed out the amperage? Have you had an electrician confirm this?

[Mark C.]

post a photo of fuze box

[Bill Kielb]

7 hours ago, Christine Belt said:

Question is are there multiple ways to wire these kilns so that they can run either or?  

No, they cannot really be wired for less amperage. A 50 amp kiln requires more power than your present and is likely larger in size and needs more power to fire to temperature.. Post a photo, you likely can change the 30 amp circuit for a 50 amp so space may not be an issue as well unless you intend to try and run both kilns concurrently. Make sure you post the photo of your electric panel (context view) and the current 30 amp breaker. Also post the make and model of the kiln you intend to install. A picture of the equipment tag would be best. Folks here will look up and confirm the  proper circuit size and wire size by the manufacture. Kilns are a bit of a specialty so not all electricians are familiar. Good to have a double check IMO.

Finally, post a picture of any panel diagram and electric panel model information usually on thee inside of the door. It may be tandem rated which could be a reasonable way to free up space.

If you have real fuses then you may be out of space and /;or at capacity. If you have breakers ( not fuses) then the photos will be very helpful.

Edited December 28, 2023 by Bill Kielb

[Snickerhaus Studio]

Thank you everyone for your speedy response.  I shared with my husband and he asked that I thank all of you for your input.  The current kiln is outside our home in what I call a kilnhouse.  Purposely built to house a kiln.  The wiring is buried and limited to go any more than 30 amps.  We were told by an electrician due to what we have in our breaker box.  My current kiln is working, but was bought many years ago used.  Was told it was from a school.  I don’t know if they had changed the wiring but I am sure the wiring will have to be changed out soon.  It is a manual cone sitter. Will continue to decide what is best to do going forward.  I am not an expert when it comes to electricity.  I am assuming the wire used to go out to the kiln can’t go any higher even if we had more power from the house and breaker box.  

[neilestrick]

2 hours ago, Christine Belt said:

I am assuming the wire used to go out to the kiln can’t go any higher even if we had more power from the house and breaker box.  

Higher amperage requires larger wires. If they ran conduit out to the kiln shed, you may be able to pull larger wires to accommodate the larger kiln. I would also double check on what they mean by not being able to do more because of the breaker box. If they mean the box doesn't have room for more breakers, that doesn't matter because you'll be replacing the old kiln breaker with a new one. If they mean you've used up all the available amperage, it may be that you can fire the kiln, but you can't run the clothes dryer or AC at the same time or something like that. How big is the main box- 100 amps or 200 amps?

[Bill Kielb]

3 hours ago, Christine Belt said:

Will continue to decide what is best to do going forward.  I am not an expert when it comes to electricity.  I am assuming the wire used to go out to the kiln can’t go any higher even if we had more power from the house and breaker box.  

if you have the time
Posting the pictures mentioned above could go a long way to helping understand what is likely possible to help with your decision.

[Snickerhaus Studio]

[Snickerhaus Studio]

The buried wire goes quite far and bends. 

[Snickerhaus Studio]

[Snickerhaus Studio]

6 hours ago, neilestrick said:

Higher amperage requires larger wires. If they ran conduit out to the kiln shed, you may be able to pull larger wires to accommodate the larger kiln. I would also double check on what they mean by not being able to do more because of the breaker box. If they mean the box doesn't have room for more breakers, that doesn't matter because you'll be replacing the old kiln breaker with a new one. If they mean you've used up all the available amperage, it may be that you can fire the kiln, but you can't run the clothes dryer or AC at the same time or something like that. How big is the main box- 100 amps or 200 amps?

150 amps

[Bill Kielb]

Nice picture's

Your current kiln is 7200 watts and rated at 30 amps. Your fuse size or breaker by manufacture specification is 40 amps, not 30 with a wire size of no 8. The good news is it looks to be run in pipe under the patio so likely possible to pull out the old and pull in new and simply replace the current breaker with a breaker sized correctly for the kiln. If pipe was not run under the patio and this is underground cable with pipe stubs at each end but then continues with underground cable in between then replacement likely means rerouting to get to the kiln with pipe and wire. (Very  doable in my experience from your pictures) 

So best case, just pull new wire and change breaker, worst case probable pipe up and over under deck and drop down in open soil behind kiln. This could be run tight on surface of the retaining wall with heavy wall pipe and then enter the kiln house, so no need to bury this if you choose not to or it’s just too difficult. Also could re supply aerially between the bottom of the deck and kiln house. Maybe a liquid tight loop neatly between the deck and side of the kiln house neatly between junctions with a drip loop.

Something to check for, a 40 amp breaker and #8 wire in its present condition. The manufacture requires it and code considers these to be a continuous load so minimum breaker size would be 1.25 X30= 37.5 A, and maximum breaker size would be 1.5 X 30.= 45 amps. So a 40 amp breaker would be the logical choice.

I am going to stop here, none of this is that difficult btw IMO, I have trades do this type of retrofit work daily. Your panel is likely rated 150 amps but may very well have a 100 amp main breaker as many old 20 position panels do. Regardless, sizing this main breaker is not based on adding up what the breakers are rated in the panel, it’s based on load, allowed typical use and is calculated a very specific way according to code. Worst case when we install, high speed EV chargers this can come in to play and a device is made to prevent the use of an electric dryer for instance while the EV circuit is use. If necessary, you could very likely do the same thing if necessary manually or automatically.

Some other observations: you have several tandem breakers (3) sort of randomly placed in the panel. These most often will be permitted in one area of the panel, say the bottom 4 openings. While not always the case, a clear picture of the panel label with a readable model number would be helpful.

Anyway, time to stop. Looks like the breaker is too small currently ( Common mistake by many electricians with kilns) but all is piped so a bigger kiln is likely just pulling new wires and new breaker.  Some pictures below of: your current kiln manufactures wiring diagram, manufactures requirements for breaker and wiring and a quick pic of heavy wall piping (happens to be heat pumps on a mid rise roof but does show neatly piped on surface stuff) just so you know it’s done everyday and yours really can be mostly hidden under the deck, only if it’s needed………. No use in breaking the concrete.

Beautiful setup by the way, unfortunately undersized breaker and likely undersized wire which I suggest you correct.

PDF copy of A&b manual here with electric specs https://ltt.arizona.edu/sites/ltt.lab.arizona.edu/files/SM and MED Paragon A and B series Instruction and Service Manual.pdf

Edited December 29, 2023 by Bill Kielb

[Mark C.]

Its a non issue-all an electrician has to do is pull the old wire to the cute kiln house and install a larger new # 6 wire-. The 30 amp breaker comes out a new 60 amp  doublke breaker goes in.

That will work easy if that conduit is 1 inch under the cement if its 3/4 its still possiable but a much harder pull and smaller ground wire . You need the newer smaller copper Number #6 wire either way.

It looks like a sub panel juction box is inside shed as well-That needs to be looked at.

whats not klnow to me is what other lights outelet in shed and how thay are powered? 

What is the size breaker for whole kin shed 40-50 or 60 amps?  its a key question

Worse case a new run on the surface in conduit

Edited December 29, 2023 by Mark C.

[Bill Kielb]

3 hours ago, Mark C. said:

ts a non issue-all an electrician has to do is pull the old wire to the cute kiln house and install a larger new # 6 wire-. The 30 amp breaker comes out a new 60 amp  doublke breaker goes in.

Yeah - I would caution not to lose track that the current breaker is undersized and likely the wire. Getting a new kiln and just rewiring may make more sense than just upsizing this to 40 amps and the appropriate wire. Whatever kiln you get, look up the manufactures wiring requirements and give to your electrician. Electricians and kilns often not so great. 

[Mark C.]

52 minutes ago, Bill Kielb said:

Yeah - I would caution not to lose track that the current breaker is undersized and likely the wire. Getting a new kiln and just rewiring may make more sense than just upsizing this to 40 amps and the appropriate wire. Whatever kiln you get, look up the manufactures wiring requirements and give to your electrician. Electricians and kilns often not so great. 

I get that the 30 amp is undersized-my point is the whole outbuilding undersized as well or just the kiln? 30 amps to a kiln building is way to small so I'm saying up size the supply to kiln shed 

The whole shed cannot just be on a 30 amp #10 wire? if so have the whole shed rewired back to main breaker

[Mudfish1]

This thread made me curious about #6 vs #8 wire to carry 50 amps. I found this link that might be useful, it seems to indicate that you could use the existing #8 wire for a 50 amp circuit if your distance is less than 75'. 

 

[Bill Kielb]

7 hours ago, Mark C. said:

The whole shed cannot just be on a 30 amp #10 wire? if so have the whole shed rewired back to main breake

Yes of course it would be way too small. From her pictures the 30 amp on 13,15 seems devoted for the kiln and my guess one or more of the tandems is devoted for lights and an outlet or two. The massive pull box ( likely In lieu of a sub panel) seems to be  for distribution of the kiln circuit and whatever other circuits were run, which makes the UG piping potentially very small as well. Whatever was done, I want to stress fixing the kiln wiring which we know is likely small by the breaker size even if other stuff is on their own circuit. I don’t want to suggest just running a bigger circuit though (which would suggest adding a sub panel) and feed the kiln and other stuff to fix the kiln issue. Combining loads is much more complicated with respect to computing breaker size. Most likely any kiln she gets will not require a neutral like the current one, so another reason to fix the kiln in an appropriate fashion. Changing this to single feed requires adding a sub panel, appropriate sized neutral for all loads and a correctly sized ground.  Probably a bit costly. Leaving the other circuits and neatly running the kiln wire on surface, probably least costly.

Edited December 29, 2023 by Bill Kielb

[Hulk]

Hi Mudfish1,

Sorry about the delay getting your 2nd post (above) approved.
Forum Administration and Moderators are testing an edit to new member registration, which should reduce (perhaps eliminate) the Spam posted here.

We ran #6 wire for new 48 amp kiln, a bit less than fifty feet from breaker to the fuse box by the kiln.
  The specs call for a 60 amp breaker, #6 wire.

The difference - typical periodic loads vs. ceramic kiln - may have to do with "continuous load" - where the kiln is drawing the full 48 amps for extended periods.

Please check back for updates from device/electrical authorities.

Edited December 29, 2023 by Hulk
minor edit

[Snickerhaus Studio]

Thank you all once again for your thorough input!  I am forwarding all to my husband who is currently at work.  He will get back to this discussion later.  To me, it seems like our current panel is already pushed to the limit?  May need to bring in a whole new line from the pole and drop down?  Please excuse my lack of knowledge on the correct wording.    Thank you for the complement on the set up. So much planning and work went into it, sadly without knowledge of kiln failure and having to replace wiring in the kiln.  Also, we didn’t know how 30 amps is now very limited.  I will post more detailed photos of our panel.  Don’t know if the marking is completely updated. The other electrical to the kilnhouse are two plugins and one light.   Coming in through the same as the 220 for the kiln.   I believe the line is at least 5” buried. 

[Bill Kielb]

52 minutes ago, Christine Belt said:

To me, it seems like our current panel is already pushed to the limit?

It is full, but again calculating how a panel is loaded is not simply adding the amperage’s on the breakers. Each load has intermittent usage.  All loads are calculated using their actual wattage with usage a factor, so not their breaker size. In reality you would move from your present 7500 watts (old kiln) to 10,000 or 11000 watts (theoretical new kiln), so prox. 4000 watt increase. There is a fallback where when firing the kiln, something else would not be used. Your dryer would be a good candidate it should be 4500 w (nominal). So your dryer would not be used for roughly 12 hours per firing.  I think there is a good chance that a new kiln feed would be fairly easy to run independently and leave the other circuits as wired. So the intent is not to scare you but make sure it gets done safely.

If you can post a clear picture of the panel model number I can look up any tandem breaker (positional) requirements for it and get the document for your electrician. Quite a bit of this could have been done easier, less invasive and more appropriate for future expansion - just my opinion though.

Edited December 29, 2023 by Bill Kielb

[Bill Kielb]

9 hours ago, Mudfish1 said:

This thread made me curious about #6 vs #8 wire to carry 50 amps.

While technically possible by temperature rating, ALL the components in the circuit would need 75c rating which for older kilns may not be the case. Kilns are pretty underpowered to start so the old rule of thumb of 3% voltage drop can be punitive IMO. I usually discourage the smallest wire solution and encourage the larger, whether for future expansion or just to limit the voltage drop to less than 1% If possible.

 

[Snickerhaus Studio]

40 minutes ago, Bill Kielb said:

It is full, but again calculating how a panel is loaded is not simply adding the amperage’s on the breakers. Each load has intermittent usage.  All loads are calculated using their actual wattage with usage a factor, so not their breaker size. In reality you would move from your present 7500 watts (old kiln) to 10,000 or 11000 watts (theoretical new kiln), so prox. 4000 watt increase. There is a fallback where when firing the kiln, something else would not be used. Your dryer would be a good candidate it should be 4500 w (nominal). So your dryer would not be used for roughly 12 hours per firing.  I think there is a good chance that a new kiln feed would be fairly easy to run independently and leave the other circuits as wired. So the intent is not to scare you but make sure it gets done safely.

If you can post a clear picture of the panel model number I can look up any tandem breaker (positional) requirements for it and get the document for your electrician. Quite a bit of this could have been done easier, less invasive and more appropriate for future expansion - just my opinion though.

 

[neilestrick]

There's a lot of stuff pulling power from that box, so like Bill said, if you're firing a 50 amp kiln you're going to have to make sure you're not using some of the other things like the dryer, stove, and maybe even the A/C. If you can afford it, the best thing to do would be to upgrade the main service to 200 amps.

In regards to the wire size/amperage issue, kiln manufacturers typically recommend the 60C ratings, so #6 for 50 amps, and safety inspectors usually want it done to manufacturer's specs.

[Mudfish1]

Hi Bill, your responses really helped me understand more about how things work! Super helpful.

Snickerhaus - I built a pottery shed in my back yard a few years ago, and had an electrician install a 80 Amp 240 V circuit that ran from my main electrical panel on my house.

While heavy gauge wire is expensive, the materials cost (wire, conduit, breakers) was less than the LABOR cost from the electrician to install everything. The lesson I learned was to plan for the most amperage/voltage I could imagine ever needing, and have the electrician install the needed wire and breakers. It cost a little more up front, but again the main cost for everything was the labor itself. Now I can move to a larger kiln in the future without worrying about doing another round of expensive electrical upgrades.

Hope that perspective is helpful.