Friday, March 29, 2024, 8:11 AM
Site: BUNN Learning Center
Course: BUNN Learning Center (BLC)
Glossary: BUNN Glossary
L

Last On-Time

During a pulse brew, this is the time set for the second on-time, and each alternating on-time for the remainder of the brew cycle.

Limit Thermostat

A limit thermostat is a safety device designed to open or break the circuit in high temperature or high current situations. They are rated for both current and temperature.

Liquid Level Control Board

The liquid level control board is an electronic device designed to automatically fill the brew tank with water when it senses a low level condition. It works in conjunction with the Liquid Level Probe and tank ground. A low AC signal is applied to the probe from this board. Minerals in the water complete the path from the probe to ground. When no ground is present and the machine is “on”, the liquid level board will then send a signal to the refill solenoid to energize. It will de-energize when the probe again senses water.

Liquid Level Probe

The liquid level probe is a sensor that monitors the water level in the tank. When water comes in contact with the probe it completes the circuit to ground. Once the circuit is complete the control board knows the take is full and opens the refill circuit shutting off the incoming water supply.

M

Main Screen

The term used to describe the screen that is displayed when the brewer is not in use. This screen is also displayed after exiting the programming mode.

Mechanical Control Thermostat

A control thermostat is a device designed to keep water at a constant temperature. It is preset for a specific temperature and will open and close its contacts to maintain that temperature.

Microprocessor

A microprocessor carries out a number of electronic functions in an integrated circuit. The microprocessors found in BUNN equipment are used to control water temperature, water delivery, motors, and other integrated components needed for machine operation.

Multimeter

The multimeter is a handheld instrument designed to measure current, resistance, and capacitance. As one of the most valuable tools a technician uses on the job, it is important that it is used correctly. Before using a multimeter you should read the safety information and become familiar with the safety warnings and cautions. Taking the time to review the safety information is for your own safety as well as protecting the meter and all the equipment involved.

N

No-Name Coffee

The term for the recipe used by the brewer when there is no coffee name stored in the funnel. The brewer can contain separate No-Name recipes for the left and right brewing positions.
O

Off-Time

During a pulse brew or preinfusion, this is the time set for the length of time that the water is not spraying over the grounds.
P

Peristaltic Pump

A peristaltic pump is a type of positive displacement pump used for pumping a variety of fluids. The fluid is contained within a flexible tube fitted inside a circular pump casing. A rotor with a number of ‘rollers’ attached to the external circumference compresses the flexible tube. As the rotor turns, the part of tube under compression closes forcing the fluid through the tube. Peristaltic pumps are typically used to pump fluids to prevent contamination from the pump or other outside contaminates.

Powder Auger Motor

This motor is used to rotate the hopper gear to deliver powder to the mixing chamber in powder drink machines. The motor is used to control the flow of product to the mixing chamber by increasing or decreasing DC voltage in 2.5% increments.

Pre-infusion

The process of beginning a brewing cycle with an initial spray of water onto the grounds followed by a pause in the spray. After the programmed pause, the spray continues without interruption until the end of the brewing cycle.

Pulse Brew

The process which allows the brew water to start, then stop, repeatedly, over the grounds in order to derive the best flavor from the coffee. Pulse brew is also used in some instances to prevent a funnel overflow. 
R

Recipe

Set of brewing parameters stored in the brewer. The parameters are unique for each coffee name and include brew ounces, pulse brew, percent bypass, pre-infusion and drip time.

Recipe Card

An assembly consisting of a computer chip and an instruction label. Used for loading a recipe into the brewer and the companion DBC Grinder.

Rectifier

A rectifier is a solid state device designed to convert AC to DC. It can be as simple as a single diode to the more complex bridge or full wave rectifier, which is a combination of 4 diodes in a package.

Refractometer

A Refractometer is used to read the amount of sugar content in products (Brixing). When light shines through a few drops of the product, it is refracted (bent) similar to a prism. The most critical part is to calibrate with distilled or R.O. water first.

Regulator

A water regulator is a device used to moderate water pressure. It will assist in keeping the pressure at a consistent level, especially important in siphon systems.

Relay

A relay is a device that acts as an electrified switch. It consists of a set of contacts, an iron core plunger and a coil. The objective of the relay is to change the “state” of the contacts – they are known as being “normally open” or “normally closed”. When voltage is applied, the coil becomes an electromagnet, causing the iron core to draw up and physically trip the contacts from their normal state.

RPM Feedback

Technology on auger motors in BUNN specialty drink systems that monitor the auger revolutions per minute (RPM) and controls powder dosing for each beverage, eliminating product waste and ensuring consistency cup-to-cup.

RPM Sensor

A device used to measure the time between pulses for the purpose of monitoring RPM (revolution per minute).

S

Safety-Fresh®

A brew-through lid with a vapor seal to maintain freshness and a spill prevention design.

Satellite Brewer

A system that includes a mother brewing system that remains in one location (e.g., kitchen) and dispenses into portable, or removable, servers for remote service.

Smart Funnel®

A funnel designed with a microchip that can receive information from an enabled grinder and transfer that information to an enabled brewer, managing the grinding and brewing process from start to finish. A SMART Funnel can be programmed to accept dedicated recipe information, reducing labor costs and minimizing brewing errors. Used in conjunction with BrewWISE technology.

Smart Hopper®

A hopper designed with a microchip that communicates the type of coffee contained in the hopper to an enabled grinder, managing the grinding and brewing process from start to finish. Used in conjunction with BrewWISE technology.

SmartWAVE®

Turbulence is an important element in brewing perfect coffee. SmartWAVE is a BUNN exclusive product design that uses technology to increase turbulence in the brew funnel, providing more contact between water and coffee and uniformity of extraction.

Soft Heat®

A docking server system with technology that thermostatically controls and automatically shuts off heat in the docking system once the preset temperature is reached and additionally monitors server volume. This is more beneficial than traditional warmer plates that heat continuously.

Solenoids

A solenoid is a device that acts as an electrified faucet. It consists of a valve body, seat cup/plunger assembly and an electromagnetic coil. When voltage is applied, the coil will draw the iron core plunger away from the valve body and allow water to flow past the seat cup (diaphragm).

Spanner Wrench

Hayes Solenoid Spanner Wrench
The Hayes spanner wrench is used only when rebuilding Hayes style solenoid valves. This tool is used in conjunction with a crescent or open-ended wrench.

Skinner Solenoid Spanner Wrench
The Skinner spanner wrench is used only when rebuilding Skinner style solenoid valves. This tool is used in conjunction with a crescent or open-ended wrench.

SplashGard®

An exclusive design with a shield next to the funnel handle that deflects hot liquids away from the user’s hand.

Static Water Pressure

Static pressure is the measurement of water that is not moving or flowing.

Switches

Switches are devices designed to allow current/voltage to pass or not to pass, depending on whether it is "open" or "closed". There are many different configurations available to satisfy many different applications. They are as simple as a single pole, single throw (wall switch), to the much more sophisticated "gauge" type switches that have multiple layers and can switch many components off or on at the same time. They come in many different packages as well. Membrane switches are common in touch pads, float switches are reed switches that are activated by magnets, and mechanical switches are sets of contacts.

T

Thermal Cutt-Off

Thermal cut off, or sometimes referred to as TCO, is a fuse that acts in the same way as a limit thermostat. If the temperature reaches a certain level the TCO fuse will blow just the same as any other fuse, cutting power to the tank heater. The TCO is also current sensitive.

Thermistor

A thermistor is a temperature sensitive resistor used to monitor temperatures. It changes value as it cools or heats. NTC (Negative Temperature Coefficient) thermistors will decrease in ohms value as it heats, and are commonly used in temperature sensing. PTC (Positive Temperature Coefficient) thermistors increase in ohms value and are generally used in protective circuits by monitoring over current conditions.

Thermoelectric Cooler (Peltier Device)

A thermoelectric cooler (TEC) is a small cooling device that relies on a Peltier junction. Composed of two conductors made of different materials, a Peltier junction acts as a heat pump which can cool or warm when current is passed through it. For example as current passes through one side is hot and the other is cold. This device is used to chill, (approximately 20º from ambient air temperature), but not refrigerate concentrate product.

ThermoFresh®

BUNN offers a full line of vacuum-insulated servers and brewers that brew directly into these servers that keep coffee at optimal flavor for hours and save on energy consumption and by not requiring warming plates.

Timer Board

The timer board is designed to provide the voltage to a specific device in order to energize it. It can energize a relay, inlet solenoid, pump, dump valve or other device for brewing or can energize a motor to grind coffee, to name a few.

Torque Sensing Board

The board consists of an inferred LED and a photo transistor which monitor the auger shaft and motor pin distance. The microprocessor will determine the shut off point of the refrigerant solenoid in relation to the thickness (distance) setting in the function menu.

Total Dissolved Solids (TDS)

Total dissolved solids, or TDS, is the total weight of the solids that are dissolved in the water, given in ppm per unit volume of water.

Transformer

A transformer is a device used to step a voltage up or down and isolate circuits. It consists of two sets of windings (lengths of coated wires), which have no electrical connection to each other. An AC voltage is applied to the primary winding, which generates a field of flux. This action causes the secondary of the transformer to generate a stepped-down AC voltage. In BUNN equipment, 12 volt and 24 volt step down transformers are most common.

Triac

A triac is a solid-state device that performs the same function as a relay, without the moving parts. Its construction is T-1 (terminal), T-2, and a gate. Normal state of a triac is “open” between T-1 and T-2. Applying a small AC voltage to the gate activates it, which then “shorts” or closes the two terminals and allows current to pass. Because there are no moving parts, a triac has no contacts and will not “pit” and wear out like a relay can.

U

Ultra Auger Motor

This motor is used to rotate the auger; mixing the product and shaving the ice off the cooling drum. The motor has a fixed RPM speed.

Universal Power Supply

The Universal Power Supply, (UPS), is used to convert variations of line voltage to 24 VDC. The power supply powers all internal components except for the tank heater, which operates on line voltage.

V

Venturi Assembly

The venturi assembly creates a siphon that pulls product through the valve, where water and concentrate are mixed during a dispense. The water under pressure flows through a narrow or restricted area, which increases the speed or velocity of the water in the valve. The increased speed of the water creates a low pressure at that point creating a suction or vacuum pulling the concentrate into the assembly where it is mixed with the water.

W

Wetting

Grounds begin to absorb hot water from the sprayhead and release gasses from the coffee. Part of the brewing process that includes Extraction and Hydrolysis.

Whipper Motor

A high speed motor used to rotate a frother blade to blend product (powder) and water during a beverage dispense.