EvenHeat kh18 trouble

D

Dillon.s

Joined
Mar 29, 2017
Messages
12
Hey all hopping to gain some insight on the problem with my kiln, as I turned it on this morn at 8 and Even by 3 it would not budge past 1880. So I cut my losses and still quenched even tho target temp was 1950.

Typically my oven has always taken 2-3hrs something more to ramp from 1400 to 1950 and after looking into some stuff today I see lots of ppl say they will ramp in 30mins- 1hr so now I’m wounder if there is something wrong with my oven especially after today’s struggle and not even reaching temp.

so this is where I’m not sure all the areas to check or values I should look for. As I tried to dig up and will continue to look for but hope and appreciate any insight.

my kiln is a evenheat (KH 418 RM PI)
And have probly only ran it maybe 30 times always in the 1900-2000 range

does anyone know:
- element ohm value on this unit
- is there away to test TC or could it just not be ready proper temp as it has been bumped one or twice in the past

any help would be greatly appreciated as I feel at a loss after today

thanks,
Dillon
 
Things to try/ check:
Is the resistance of the heating coil hat it should be per mfgs specs?

could be a measurement issue: is the thermocouple in good shape and positioned correctly?

is the pid truly “full on”? Try a fully manual mode with the elements definitively full on, and see what temperature time profile looks like.

is there something else running on the electrical circuit that could be pulling the voltage down?
 
Is it a 220 or a 110 oven. I have a DIY oven but if it is 220 and a SSR failed or your burned out a fuse you may only be getting 110 through the coil.

This is based on a personal build so a commercial oven may be a different design.

If its a single coil until, make sure a coil hasn't sagged and contacted another coil causing a short and reducing the heating capacity. If its a multiple coil until in parallel you may have burned out one coil but you should see that when opening the door.

Again, all uneducated guesses but easy to check.
 
So I called evenheat and he said coil should be 8.8 ohms. So opened mine up and it’s reading 9.8 ohms so a lil bit worn as my kiln should be putting out 1560watts but 120/9.8Ohms=12.25amps
120x12.25=1470watts

so I thought I’d move it out of the cold basement into a room and turn heat on and try again today. Hopping warmer room would help midigate some of the heat loss. But after running I took a voltage reading at the panel and both L1 and L2 are sitting at 103 volts so realistically I’m only getting
103v/9.8ohms=10.51amps
103v X 10.51A= 1082watts so close to 400w I’m not getting

so am waiting to see if it will reach temp in different room and depending on out come after I turn it off I will check voltage again to see how much or if it is the kiln drawing down voltage. As it’s only a 120v unit and both lines are down at 103volts so makes me think maybe might be with utility or other ppl on the block running A/C units is drawing power down. But will post my findings
 
That does sound pretty low (I think it is not supposed to be allowed to drop below 110 or 114. The utility is **supposed* to control the feed to keep the voltages up. Maybe give them a call and ask whether they have been having some load problems they are having trouble compensating for?
 
Definitely think it’s utility as both neighbours are sitting at the same 103volts. Phone line is busy but plan to get ahold of them.

On a positive note moving kiln to heated room it has ran for just over 3hrs and is at 1960 :) makes me think the pwr was maybe even lower yesterday or the cold basment was limiting it a bit.

anyone know what ball park a Nicholson file RC is as the 4 knives I did yesterday didn’t fully get to temp (s35vn) only 1860 when I quenched. Drill bit started to drill tang but was squealing something awful and file will bite but only if I am laying into it with lots of pressure.

think it’s worth finishing knives?
 
The room temperature makes no significant difference. The basement is maybe 35 degrees and the upstairs room is 70 degrees? that is a difference of 35 degrees. That makes no difference in the oven heating to 1950 degrees.

If I were you I would be asking myself why the oven takes three hours to do what it should do in less than one hour. Something is drastically off. I suspect the coils are shorted or one is burned out.
 
Stacy E. Apelt - Bladesmith said:
The room temperature makes no significant difference. The basement is maybe 35 degrees and the upstairs room is 70 degrees? that is a difference of 35 degrees. That makes no difference in the oven heating to 1950 degrees.

If I were you I would be asking myself why the oven takes three hours to do what it should do in less than one hour. Something is drastically off. I suspect the coils are shorted or one is burned out.
Click to expand...

there’s zero circumstances where an oven that big, which is 120v, would get that hot in under an hour. At best it’d be 90 min under perfect conditions
 
If you say so. Please note that he said it usually takes 2-3 hours to ramp from 1400 to 1950 and now it won't go past 1880 after 5 hours. That is not normal.

Here are the specs on the KH418:
KH 418 Specifications
18" Deep x 6.5" Wide x 4.25" High - 0.29 Cubic Feet

Maximum temp - 2200°F (1204°C)

120 Volts, 13 Amps, 1560 Watts, 60Hz, Single Phase

Power Cord Plug Configuration - NEMA 5-15 (Standard Household Plug)
https://www.evenheat-kiln.com/kh-series-knife-ovens
 
Stacy E. Apelt - Bladesmith said:
If you say so. Please note that he said it usually takes 2-3 hours to ramp from 1400 to 1950 and now it won't go past 1880 after 5 hours. That is not normal.

Here are the specs on the KH418:
KH 418 Specifications
18" Deep x 6.5" Wide x 4.25" High - 0.29 Cubic Feet

Maximum temp - 2200°F (1204°C)

120 Volts, 13 Amps, 1560 Watts, 60Hz, Single Phase

Power Cord Plug Configuration - NEMA 5-15 (Standard Household Plug)
https://www.evenheat-kiln.com/kh-series-knife-ovens
Click to expand...

he also said when he changed outlets it got to 1960 in 3 hours. People with that same oven regularly report it takes 2+ hours to get to 1950*. With his outlets not getting full power 3 hours seems completely normal
 
I agree that there is likely also a power issue here, but 2 to 3 hours to rise the last 500 degrees is abnormally long. I had an earlier version of the same 120V Evenheat oven and it took about 60 to 90 minutes to go from cold to 1900°F. (The oven originally belonged to Ron Fraser, and after I changed the old analog controller to PID it is still running at my SIL's shop today.)

But, all this is just subjective until the OP determines his incoming line voltage, the ovens coil condition, if the TC is reading correct, and if the controller is programmed right.

One thing I didn't think to ask is what the program heating rate is set at.
 
Stacy E. Apelt - Bladesmith said:
I agree that there is likely also a power issue here, but 2 to 3 hours to rise the last 500 degrees is abnormally long. I had an earlier version of the same 120V Evenheat oven and it took about 60 to 90 minutes to go from cold to 1900°F. (The oven originally belonged to Ron Fraser, and after I changed the old analog controller to PID it is still running at my SIL's shop today.)

But, all this is just subjective until the OP determines his incoming line voltage, the ovens coil condition, if the TC is reading correct, and if the controller is programmed right.

One thing I didn't think to ask is what the program heating rate is set at.
Click to expand...

he said it took 3 hours to go from cold to 1950 after moving outlets. Not last 500 degrees
 
"Typically my oven has always taken 2-3hrs something (sometimes?) more to ramp from 1400 to 1950"

We should continue any further discussion about his statements and problem between us off the thread. Email or PM me if you havemore to discuss.
 
For what it's worth, I have the KH418 and it gets to 1950 in under two hours. Here's a graph from one firing:
tUlVdbM.png

tUlVdbM.png)
 
I can only hope to have a HT that gets to temp that fast.
I did get in touch with utility looks like my incoming pwr is a lil low at 110v but still acceptable in there eyes I was told I plant to take my oven and run a cycle at attends for next months HT as at least his pwr is at 123v also I do have my ramp programmed to 9999 so I believe it should be set up to be trying to get to temp as fast as possible. Also I know the are newer styles of these kilns as mine is an older one with only one coil in it don’t know if the new ones with three are any bit more efficient because of coil placement but anyways plan to try next Batch at a friends with higher voltage and not sure if having around a loss of 150watts ish is my promlem due to lower voltage at my shop
 
That 103 VAC reading is certainly low and would cause oven to take longer than normal to heat up. What's really important is the voltage at the plug while the oven is in heat cycle to be sure the voltage isn't dropping even more.

Lee: My EvenHeat 418 with 240 vac and >3,000 watts doesn't heat up much quicker than your Your 110 vac KH418 with only 1500 watts, I've always felt my oven was a tad slow to heat.
 
Ken, that's interesting. I love my kiln, but I wondered at the time if I should spend the extra money to run a 220v circuit and get a 220v unit. I kinda wondered what I was missing getting the 1500watt kiln. I'm just a hobby knife maker so I heat treat something at most twice a month, so it probably doesn't really matter for my purposes. For what it's worth, I got the Bill Burke modification on my kiln, which wraps it in a layer of insulation outside of the bricks, between the bricks and the stainless body.
 
FWIW, I had my 220VAC K22.5 out Sunday and ramped to 1250 in maybe 15 or 20 minutes for a three hour sub-critical anneal. I later ramped to 1950 for a stainless HT ( different blade) and it took less that 30 minutes for that climb. It takes a LOT longer to cool down!
 
You must log in or register to reply here.
Back
Top