Unit 3 Machine Composition
Unit Objectives
Given a realistic scenario in which the learner has access to the machine’s internal components the learner
will understand the composition and functions of the brewer.
Given a realistic scenario requiring the learner to access the internal components of the machine the learner will be able to remove the front panel and top cover.
The learner will disconnect the electrical and water supply.
The learner will remove the front panel and top cover.
Given an operating machine the learner will be able to give a general explanation of how the unit operates.
The learner will be able to identify the functions of the main control board and identify the
components that correspond to each triac.
The learner will be able to identify the components and functions of the filling system.
The learner will be able to identify the components and functions of the heating system.
The learner will be able to identify the components and functions of the dispensing system.
The learner will be able to identify the components and functions of the coffee holding system.
Machine Composition
Exterior Overview
Product Outlets and Removable Parts
User interface (1)
Display (mounted to the control board) (2)
Hot water outlet (3)
Funnel sensing coil (4)
Funnel (5)
Server (6)
Data plate (7)
User Interface
The user interface is a membrane switch adhered to the front of the brewer. The membrane is connected to the control board by a ribbon cable. The user interface allows the user to select product size and begin a brew cycle.
The machine’s display is mounted to the control board. The display is visible on the front of the machine and provides
information to the user and to the technician.
Batch Selector Switches
On/Off Switch
Brew Start Switch
Funnel Sensing Coils
Accessing the Inside of the Brewer
The majority of service work done to the BrewWISE® brewer will require the service technician to access the inside
of the unit. The brewer has three removable panels to facilitate access- the front panel, the top panel, and the server
base panel. Depending on the repair the technician may have to remove one or all of these panels.
In order to work safely the power should be disconnected prior to removal of any body panel. Once the panels are
removed the power can be reconnected in order to troubleshoot the machine.
The top panel is secured with 4 small flat head screws. To the remove the panel, remove the four screws, lift the front
of the panel up and slide the rear backwards to unhook the panel from the brewer’s body.
To remove the front panel, first remove the funnels and servers from the machine. The front panel is secured to the
brewer with 11 standard screws. Remove the screws and pull the panel straight off of the unit.
TF BrewWISE® Training Manual
Machine Function and Operations
Main Control Board
Main Control Board
The main control board is the brain of the brewer. In the Digital
Brewer Control (DBC®) system, the control board is the single component that contains all of the programming software, it interprets
all the data it receives from the level and temperature sensors and
activates components to fulfill those demands. The main control
board responds to the users input through the membrane switch and
activates and controls the brew cycle. The control board can receive
data from Smart Funnels® through the sensing coils on the front of
the machine.
The control board is interchangeable between the single and dual
brewers. There is jumper located on the board to select either single
or dual with dual being default.
In a digital brewer the control board takes the place of the
liquid level control board, the timer board, and the mechancal thermostat. All of these components are combined into a single
Filling System
The fill system maintains the level of water in the brewer’s tank. Anytime water is drawn off of the tank during a brew
cycle, the fill circuit activates to refill the tank.
The fill system consists of:
• 120VAC solenoid inlet valve
• Fill probe
• Overflow cup
Water enters the brewer through the water supply line and enters the
chassis through copper tubing. The water flows through the inlet solenoid.
The inlet solenoid contains a strainer that restricts large particles from
passing through. Once water passes through the inlet solenoid, water
begins filling the tank.
The 120VAC inlet solenoid is activated by the control board anytime the
brewer calls for water. The valve opens and allows water to flow, under
line pressure, to the top of the tank where the silicon tube connects to an
stainless steel fill tube. The fill tube runs to the bottom of the tank where
the incoming water enters the tank.
The control board monitors the level of water in the tank through a low
voltage level probe mounted to the top of the tank. The control board
grounds a 2.5VAC signal to the tank through the water. If it loses this
signal, the control board will activate the inlet valve.
The brewer features an overflow safety system for the fill circuit. There is
a tube mounted on the top of the tank that will drain water if the tank fills
to the top and continues to fill. The water will drain into the overflow cup;
there is a float switch in the cup. When this switch floats to its top position this signals the control board to deactivate the fill circuit and heating
Liquid Level Probe
Float Switch
Fill Tube
Check Valve
Inlet Solenoid
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Heating System
The heating system consists of:
• Water tank
• Heating elements
• Triacs
• Contactor (3 phase only)
• High-limit thermostats
• Temperature sensor
Tank Heater Triac
The heating circuit maintains the water in the tank at a preset temperature. This ensures that the water is always
ready for brewing. Water for brewing is contained in a stainless steel tank. A Dual BrewWISE tank contains 2 heating
elements (3 heating elements if equipped for 3 phase) that are powered by the line voltage into the machine. A single
BrewWISE tank will contain 1 heating element. Each heating element is controlled by the control board through triacs. Each heating element circuit has a limit thermostat that will interrupt the circuit if the water in the tank overheats.
BrewWISE units without a neutral will have an internal step-down transformer and a 2-pole contactor. The step-down
transformer is a 204/240-120VAC transformer.
For 3-phase operation, the 2-pole contactor is used in the heating circuit in addition to a triac for controlling the elements. The contactor will control 2 heating elements while the triac will control the 3rd. During heating all 3 elements
will be energized. Once the temperature is within 2°F of target, the CPU will open the contactor and the remaining
element, controlled by the triac, will heat and maintain the water precisely at the programmed target temperature.
If a BrewWISE unit has the capability for 3 phase operation, but is installed to operate in single phase, the center
heating element and L3 position of the terminal block will not be used.
The control board monitors the water in the tank by a temperature sensor that is in contact with the water.
This temperature sensor is a digital thermistor; the control board reads the temperature as value of resistance. The temperature sensor allows the control board to trigger the two heating element triacs when the
temperature drops below its programmed value and shut down the trigger voltage when the water temperature reaches the programmed holding value.
Tank Heater
3rd Heating Element for
3 Phase goes here.
Limit Thermostat
Heater Triac
Single Tank
TF BrewWISE® Training Manual
Dual Tank
Bypass Valve
Dispensing System
The dispensing system consists of:
• Brew valve
• Bypass valve
• Sprayhead
• Funnel
• Funnel lock solenoids
Dispense Valve
The dispensing system is what makes the brewer
a coffee brewer. It dispenses the water onto the
ground coffee to create the product.
The BrewWISE® brewer is a gravity dump brewing
system. During the brew cycle the brew and bypass
valves open allowing water to flow from the tank and
out the product outlets. The control board opens and
closes these valves according to its programming
based on the specific recipe called for. The sprayhead, attached to the dispense solenoid, controls
the outlet flow rate of the water. The number and
size of the holes determines the flow rate.
Funnel Lock
The brewer has a funnel lock feature; during the brew cycle and the programmed drip out time the funnel lock solenoid will be engaged to prevent the funnel from being removed. It is important to note that the control board supplies
120 DC voltage to the funnel lock solenoid to prevent it from vibrating.
Funnel Lock Solenoid
Coffee Holding System
ThermoFresh­® servers are vacuum insulated servers that can keep coffee hot and fresh for hours.
The TF server has a removable stand for flexibility and a space saving profile. The built-in drip tray
can also be removed for cleaning purposes as well as the sight gauge and faucet assembly. The
large cup clearance allows for dispensing into cups, decanters and thermal carafes. Like thermal
servers, the TF server must be pre-heated with hot water before it can properly maintain the beverage temperature.
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