To help eliminate miscommunications, we’ve provided a convenient quick reference of industry terms.
Aluminum Heat Transfer Tape – Thermally conductive aluminum foil (.002” thick) with an adhesive backing. The aluminum tape is applied under and over the heat trace cable to increase heat transfer when heat tracing PVC or plastic pipe.
Ambient Sensing – Commonly referred to as air temperature sensing.
Ampacity – The current that a wire can carry without exceeding its temperature rating.
A.H.J. – (Authority Having Jurisdiction) the authority responsible for inspecting and approving that an installation meets the local building code.
Auto-Ignition Temperature – The minimum temperature at which a substance will self-ignite.
Braid – The conductive wire braid surrounding the heat trace cable, provides mechanical protection and an electrical ground path.
Branch Circuit – The portion of an electrical wiring system from a circuit breaker to a device or load (heating cable).
Circuit Breaker – A switch designed to protect an electrical circuit from current overload by opening the circuit when the current flow exceeds a pre-determined level.
Circuit Breaker Sizing – The method of determining the proper size of a breaker per code and application of electric heat trace.
Classified Location – An area where hazards such as flammable gas, vapor, liquid, combustible dust or ignitable fibers/flyings exist.
Cold Lead – Electrically-insulated wiring that connects heating conductors to branch circuit wiring, and designed to not product appreciable heat.
Combustible Dusts – Dust that presents a fire or explosion hazard when dispersed in air or other gaseous oxidizer.
Combustible Liquids – A liquid having a flash point at or above 100°F.
Conduction – One of three methods for transferring heat. Conduction refers to the transfer of heat through direct contact.
Conductor – A material which allows electric current to pass through it, typically in reference to an insulated wire.
Constant Wattage Heat Trace Cable – An electric heat trace cable whose power output will not change with environmental variations.
Contactor – A heavy-duty relay that controls electric power circuits.
Continuity – The complete path for current flow.
Controller - A device which utilizes input data to determine output, commonly used to control a heat trace system. Input data can be from a mechanical thermostat (bulb and capillary), RTD, thermocouple, thermistor, moisture sensor, or other device.
Convection – One of the three methods of heat transfer. Convection refers to the transfer of heat through the motion of a liquid or gas.
Corrosive Environment – An environment containing corrosive gases or liquids. The corrosive may be inside of the pipe or in the area surrounding the pipe.
Deadband – The range through which a measured signal can vary without initiating a response from controller.
Dielectric – A material that is a poor conductor of electricity, also called an insulator.
Electric Heat Trace System – A system consisting of electric heat trace cables, cable accessories, controllers, load switching devices, and possibly monitoring devices. The purpose of the system is to maintain a piping system at or above a specific temperature.
Electromechanical relay (EMR) – An electrical switch that opens or closes under the control of another electrical circuit.
Electrical Requirements – A list of parameters required to design an electric heat tracing system.
End Termination Kit – The parts used to properly terminate the end of the electric heat trace cable that is not wired to power.
Exposure Temperature – The temperature that an electric heat trace cable will be exposed to in a process heating environment.
Explosion Proof – A method for protecting electrical equipment used in Class I hazardous locations. Explosion proof equipment is capable of withstanding an internal explosion of a specified gas or vapor, and of preventing the ignition of a specified gas or vapor surrounding the enclosure.
Factory Terminated – A heat trace cable terminated by the manufacturer including cold leads.
Field Terminated – Heat trace cable cut to length in the field. Power connections, splices, and terminations are performed by the electrical contractor.
Flash Point – The minimum temperature at which a liquid can form an ignitable mixture in the air near the surface of the liquid.
Freeze Protection – A heat trace cable system designed to prevent the contents inside of a pipe from freezing.
Grounded – Connected to ground or a conductive body that extends to the ground connection.
Ground Fault – Leakage current from a circuit to ground.
Ground Fault Circuit Breaker – A circuit breaker that de-energizes a circuit when leakage current to ground exceeds a preset value.
Ground Fault Circuit Interrupter (GFCI) – A device intended to protect personnel. When an imbalance greater than 5mA occurs the device will turn off power to the cable. GFCI is required for floor warming cables.
Ground Fault Protection of Equipment (GFPE) – A device intended to protect equipment. The device monitors current balance of a heat trace cable circuit. When an imbalance greater than 30mA occurs the device will turn off power to the heat trace cable. May also be referred to as a ground fault protection device (GFPD).
Hazardous Location – Same as a Classified Location, refer to classified location definition.
Heat-Loss – The amount of heat lost from the pipe to the surrounding environment which is at a lower temperature.
Heat-Loss Calculation – A calculation for determining heat-loss using the following variables: k-factor, insulation thickness, maintain temperature, lowest ambient temperature, and the diameter of the pipe. Standard heat loss is calculated in watts per foot.
Heat Sink – A part that conducts or dissipates heat away from the pipe or equipment. Typical heat sinks are pipe supports, valves, flanges, etc. and need to be heat traced.
Heat Transfer Aids – Thermally conductive materials such as metallic foils or heat transfer cements used to conduct heat into the pipe.
High Limit Temperature – The maximum allowable temperature that heat traced component can be raised to.
High Temperature Alarm – An alarm which activates when temperature rises above the high temperature alarm set point.
Inrush Current – The initial current draw of a self-regulating PTC (positive temperature coefficient) type heat loss from the pipe.
Insulation – Material used to reduce the rate of heat loss from the pipe.
Intermittent Exposure Temperature – A periodic high temperature a pipe is exposed to typically due to steam cleaning.
Isometric – A three-dimensional line drawing of a piping system.
Junction Box – An accessible enclosure used to house heating cable terminations among other electrical uses.
Line Sensing – Pipe temperature sensing.
Low Temperature Alarm – An alarm which activates when temperature falls below the low temperature alarm set point.
Maintenance Temperature – The temperature that the pipe is maintained at for a specific process heating application.
Maximum Circuit Length – The longest length for a specific heat trace cable allowed, typically due to voltage drop or circuit breaker size.
Maximum Continuous Exposure Temperature - The highest temperature to which a component of the heat-tracing system may be continuously exposed (heater de-energized).
Maximum Maintenance Temperature – The specified highest temperature the heat trace cable is capable of maintaining continuously.
Maximum Operating Temperature – The highest temperature of the process during normal operation. This is the highest temperature the heat trace cable will be continuously exposed (whether power to the cable is on or off).
M.I. Cable - Raw mineral insulated cable.
M.I. Hangar Door Rail Deicing Cable Assembly - Factory built M.I. heating cable assembly for hangar door rail deicing applications.
M.I. Heating Cable Assemblies - Generic term for Delta-Therm's end use mineral insulated cable assemblies.
Minimum Ambient Temperature – The lowest expected temperature of the pipes surrounding medium, typically air.
Minimum Operating Temperature – The lowest temperature capable of maintaining a process.
Minimum Start-Up Temperature – The minimum temperature a self-regulating heat trace cable circuit can be energized per circuit breaker sizing.
M.I. Permafrost Prevention Cable Assembly - Factory built M.I. heating cable assembly for freezer floor permafrost prevention applications.
M.I. Pipe/Tank Trace Cable Assembly - Factory built M.I. heating cable assembly for pipe or tank trace applications.
M.I. Radiant Heating Cable Assembly - Factory built M.I. heating cable assembly for radiant heating or floor warming applications.
M.I. Roof Deicing Cable Assembly - Factory built M.I. heating cable assembly for roof, gutter, and downspout deicing applications.
M.I. Snow Melting Cable Assembly - Factory built M.I. heating cable assembly for snow melting applications.
Monitor Light – A device used for power indication of a heat trace cable.
NEC – National Electric Code.
NEMA – National Electric Manufacturers Association.
P & ID – Piping and Instrumentation Diagram.
Parallel Circuitry – Connecting heat trace cables in a parallel manner where the source voltage of each cable will be the same (the current may vary).
Parallel Heat Trace Cable – Heating elements that are electrically connected in parallel, either continuously or in zones, so that watt density per linear length is maintained throughout the cable.
Pipe Schedule – An index that specifies the nominal wall thickness as a function of pipe size.
Pipe Size – The nominal diameter of a pipe.
Pipe Support – A device used to support a section of pipe.
Pitch – The degree of slope or the distance between two points of a spiraled heat trace cable.
Power Connection Kit – The components used to properly connect one end of the electric heat trace cable to the power source. The kits are listed as part of the heat trace cable product approval for a specific application.
Product Approvals – Product safety testing to recognized safety standards per application. Most prevalent of the agencies providing testing are Underwriters Laboratories (UL), the Canadian Standards Agency (CSA), and Factory Mutual (FM). Other agencies qualify as Nationally Recognized Testing Laboratories (NRTL).
Radiation – One of three methods for transferring heat. Radiation refers to the transfer of heat through indirect contact of a warmer object and a cooler object.
Rated Output – The expected power output of a heat trace cable for specific conditions. Conditions may include applied voltage, pipe or surface temperature, and total length.
Raise and Maintain – Using heat trace cable to raise the temperature of the pipe contents and then to maintain the temperature.
RTD – (resistance temperature detector) A sensing element whose resistance is temperature dependent. The resistance value is used by a controller to control pipe temperature
Self Regulating Cable – A polymer-core heating cable whose power output is dependent on temperature, also known as self-limiting cable.
Sensor – A device capable of detecting and responding to a physical stimulus, such as temperature or moisture, and relaying this information to a control device.
Series Circuitry – Connecting heat trace cables in a series manner where the current draw through each cable will be the same (the voltages may vary).
Series Heating Cable – Connecting heat trace cables in a series manner where the current draw through each cable will be the same (the voltages may vary).
Set Point Value(s) – The temperature that a controller will maintain a heat tracing system at or between.
Sheath – A uniform and continuous covering, metallic or nonmetallic, enclosing the insulated conductors of a cable, used to protect against mechanical damage and influences from the surroundings (corrosion, moisture, etc.)
Sheath Temperature – The temperature of the outermost continuous covering of the heat trace cable that may be exposed to the surrounding atmosphere.
Solid State Relay – A switching device that has no moving parts, which opens and closes a circuit electrically.
Supply Voltage – The voltage that the electric heat trace cable will operate at.
Spiral Wrap – Installing heat trace cable in a spiral pattern around a pipe.
Splice Connection Kit – The parts used to properly connect two ends of electric heat trace cables together.
Start-Up Current – The initial current draw when a heat trace cable is energized. Also referred to as inrush current.
Temperature Differential – The difference in temperature between the lowest expected ambient temperature and the pipe maintenance temperature. Also known as Delta T.
Temperature Rating (T-Rating) – The maximum temperature that a specific heat trace cable can safely operate in a hazardous locations.
Tee Splice – The parts used to properly connect three ends of electric heat trace cables together.
Thermal Gradient (TG) Section - Temperature transition section from M.I. heating cable to a 19-strand cold lead.
Thermal Insulation – Material that has a low thermal conductivity. Thermal insulation is placed on the outside of pipes to reduce the rate of heat loss.
Thermistor – A temperature sensing component whose resistance changes in response to changes in temperature.
Thermocouple – A temperature sensing component consisting of two wires of dissimilar metals whose junction produces a temperature dependent voltage. This voltage is used to determine temperature at the junction of the dissimilar metals.
Thermostat – An automatic device for regulating temperature by controlling the supply of electricity to a heating device, can be either line or ambient temperature applications. Available in adjustable or fixed set points, mechanical, or electronic switch.
Voltage Drop – The loss of voltage on a device due to the resistance of the feeder wires from the voltage source. This also applies to the bus wires of a parallel heating cable.
Watt Density – Watts per linear foot of heat trace cable.
Weather Barrier – Material installed over the outer surface of thermal insulation to protect it from weather damage.