Salt Bath 709 / 718 / 818
Installation and Operating Manual
North American Model
June 2019
Page
25
of
36
Evenheat Salt Bath Kiln Features
Two Control Thermocouples
Evenheat salt bath kilns are equipped with two control thermocouples: Chamber (#2) and Immersion (#3).
The Chamber thermocouple measures the temperature present within the firing chamber itself. That is to say that it measures the temperature in the space between
the firebrick chamber walls and the outside of the salt pot. We use the chamber thermocouple to control the heating process up to the working temperature as
measurement of the solid salt (at start up) within the salt pot would be unreliable and potentially dangerous.
The Chamber Thermocouple is a Type K thermocouple
and plugs into the thermocouple jack #2 (middle jack) located at the back of the control panel.
The Immersion thermocouple measures the temperature of the salt bath itself. That is to say it is placed (immersed) into the salt bath and measures the molten salts
directly. It is the immersion thermocouple that you will use to determine proper salt bath temperature.
The Immersion Thermocouple is a Type K thermocouple and
plugs into the thermocouple jack #3 (upper jack), located at the back of the control panel.
When starting the salt bath process via the control, the Chamber thermocouple is automatically chosen as the controlling thermocouple. Once the chamber reaches
temperature, or once the salts become liquid, the Immersion thermocouple can be placed within the salt bath and temperature control can be switched over to work
from the immersion thermocouple. Switching between the Chamber and Immersion thermocouples is accomplished by a dedicated key on the temperature
controller itself.
Immersion Thermocouple Mount
The Immersion thermocouple includes a mount that holds and positions the immersion thermocouple within the salt pot. This mount is adjustable to fit a variety of
salt pot diameters and wall thicknesses and thermocouple diameters from 1/8” to 3/16”.
The immersion thermocouple mount allows you to position the thermocouple where you desire within the salt pot. Generally it’s better to try to keep it off the wall
and surrounded with molten salt.
Over-Temp Thermocouple Circuit
Salt bath kilns include a dedicated over-temperature thermocouple circuit. The role of this thermocouple is to monitor the firing chamber and abort the process if the
chamber exceeds 300°F of the programmed process temperature. Over-temping salts can be hazardous, particularly with nitrate
(Nitrate)
containing salts usually
found in tempering salts.
Please keep in mind that this over-temp thermocouple is a mechanical/digital device and can fail. While its function is to abort the process on a sensed over
temperature condition, it is not a safety device. It is included as a back-up to your attention to the process.
The Over-Temp Thermocouple is a Type K thermocouple
and plugs into the thermocouple jack #1 (lower jack) located at the back of the control panel.
Grounded Salt Pot and TC’s
Evenheat salt bath kilns produce heat electrically via heating elements placed into the firing chamber walls. The nature of the salt bath process exposes the user to
electrically conductive features such as the salt pot, molten salts and thermocouples. Each of these features extend into and out of the electrically charged firing
chamber. Any fault within the heating element causing it to make contact with any of these features will cause them to conduct electricity.
To protect you against any electrical faults Evenheat has provided electrical grounds on the salt pot and all thermocouples. If a fault (short circuit) occurs the
grounding of these features safely dissipates electrical energy.
Evenheat does offer salt pots for sale that are equipped with grounding hardware included. If you intend to provide your own salt pot we require that a grounding
mechanism be included in your design. Please see the end of this manual for design specifications.
TAP Control
We wanted the salt bath kilns to include special features not found in standard temperatures controls such as the Chamber/Immersion thermocouple selection and
over-temp thermocouple. The designers of the TAP control were happy to incorporate our design requirements into their control with great success. The TAP control
is our premium control and features a touchscreen that offers absolute simplicity and clarity in programming and use.
