Ovens and kilns maintenance and specifications
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Shop Area: Metal Shop
Tool: Ovens and Kilns
Requires in-person training: Yes
MT 130-08, Rev. 1
KH 418 Evenheat Kiln
Chamber Dimensions: 18" Deep x 6.5" Wide x 4.25" High Max Temperature: 2200°F
Heat Treat Oven – Kiln (Evenheat) for the heat treating of metals for knife making, gunsmithing, automotive and general machine shop work.
Evenheat Knife/Heat Treat Ovens are a controlled heat source designed for the sole purpose of heat treating metals
- KH 418 Manual (https://a9843d05-6c8c-4a08-9cea-92539c11e7e9.filesusr.com/ugd/3a9418_7aa08ef009c542e48e4d68c5958e86bb.pdf)
- KH 418 Control Interface Manual (https://a9843d05-6c8c-4a08-9cea-92539c11e7e9.filesusr.com/ugd/3a9418_1b2e140c52df4b2cbb9c5b7fdcc93439.pdf)
- The thermocouple is a temperature sensor.
- Located in the ceiling of the oven.
- Standard thermocouple is known as a Type K. The term “Type K” refers to the type of alloys used to manufacture the thermocouple.
- Thermocouple needs no maintenance other than replacement if it fails. Failure of the thermocouple is seen as an error message on the controls.
- The thermocouple must be replaced with another Type K thermocouple.
- To replace the thermocouple first unplug the oven and allow it to return to room temperature.
- The thermocouple is part of an assembly is located in the ceiling of the oven.
- Remove the 2 screws that fasten the assembly to the oven and pull it from the oven.
- Loosen the 2 screws that fasten the thermocouple to the oval shaped block and remove the thermocouple.
- Attach the replacement thermocouple to the oval shaped block with the red thermocouple lead to the red thermocouple lead wire.
- Tighten the screws.
Control Relay Replacement via the Relay Access Port:
- The oven uses a device called a relay (a.k.a. contactor) to control power to the heating element.
- During use the relay continually turns on and off to maintain the proper kiln temperature.
- The relay is a service part and is likely to need replacing at some point.
- To replace the relay use the external, relay access port.
- The relay access port allows relay replacement by removing the access plate located on the outside of the kiln control enclosure
- The insulating fire brick while strong, can be damaged with rough handling.
- Damage that is small or minor may be ignored.
- Any brick damage that affects performance should be repaired or replaced, such as brick that holds the heating elements in place.
- The electronic controls are protected with a control fuse located in a fuseholder on the backside of the oven control panel.
- The fuse is rated at 250V/250mA, slo-blo.
- If replacement is necessary, replace only with a fuse of the same rating.
- Period vacuuming of the oven chamber removes debris that may damage the heating elements.
- A gentle vacuuming with a soft brush is perfect.
- Pay particular attention to the element grooves.
- Unplug the oven before vacuuming.
- The oven jacket is Stainless Steel and requires no real maintenance or cleaning.
- The oven control panel requires no cleaning.
END OF THE PROCEDURE