Bunn ES2SA User Manual 2

BUNNEspress

ESPRESSO/CAPPUCCINO

COFFEE BREWERS

DISCONTINUED VERSION

®

The information in this manual

is no longer current.

TM

E

ES•2A

OPERATING & SERVICE MANUAL

S • 2 A

/

E S• 2 S A

/ ES•2SA

TM

P-244/P-245

BUNN-O-MATIC CORPORATION

POST OFFICE BOX 3227

SPRINGFIELD, ILLINOIS 62708-3227

PHONE: [phone] FAX: [phone]

22700.0000A 11/93 ©1993 Bunn-O-Matic Corporation

BUNN Espress™

Warranty..............................................................2

User Notices........................................................3

Features.......................................................... 4-5

Installation

Plumbing...............................................6

Electrical Requirments and Hook-up....7

Initial Setup...........................................8

INDEX

ES•2A™/ES•2SA™

Programming ........................................9

Brewing Procedures ...........................10

Cleaning............................................................11

Trouble Shooting ......................................... 12-13

Push-button Board Repacement.......................14

Replacement Parts...................................... 16-31

Wiring Diagrams.......................................... 32-33

1

BUNN Espress™

Bunn-O-Matic Corp. (“Bunn”) warrants the equipment manufactured by it to be commercially
free from defects in material and workmanship existing at the time of manufacture and
appearing within one year from the date of installation. This warranty does not apply to any
equipment, component or part that was not manufactured by Bunn or that, in Bunn’s judgement,
has been affected by misuse, neglect, alteration, improper installation or operation, improper
maintenance or repair, damage or casualty.

THE FOREGOING WARRANTY IS EXCLUSIVE AND IS IN LIEU OF ANY OTHER
WARRANTY, WRITTEN OR ORAL, EXPRESS OR IMPLIED, INCLUDING, BUT NOT
LIMITED TO, ANY IMPLIED WARRANTY OF EITHER MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE. The agents, dealers or employees of Bunn are not

authorized to make modifications to this warranty or to make additional warranties that are
binding on Bunn. Accordingly, statements by such individuals, whether oral or written, do not
constitute warranties and should not be relied upon.

The Buyer shall give Bunn prompt notice of any claim to be made under this warranty by
telephone at [phone] or by writing to Post Office Box 3227, Springfield, Illinois, 62708-

3227. If requested by Bunn, the Buyer shall ship the defective equipment prepaid to an
authorized Bunn service location. If Bunn determines, in its sole discretion, that the equipment
does not conform to the warranty, Bunn shall repair the equipment with no charge for parts
during the one year warranty period and no charge for labor for the first 90 days of the warranty
period. If Bunn determines that repair is not feasible, Bunn shall, at its sole option, replace the
equipment or refund the purchase price for the equipment.

THE BUYER’S REMEDY AGAINST BUNN FOR THE BREACH OF ANY OBLIGATION
ARISING OUT OF THE SALE OF THIS EQUIPMENT, WHETHER DERIVED FROM WAR­RANTY OR OTHERWISE, SHALL BE LIMITED, AS SPECIFIED HEREIN, TO REPAIR OR,
AT BUNN’S SOLE OPTION, REPLACEMENT OR REFUND. Bunn shall not be liable for any

other damage or loss, including, but not limited to, lost profits, lost sales, loss of use of
equipment, claims of Buyer’s customers, cost of capital, cost of down time, cost of substitute
equipment, facilities or services, or any other special, incidental or consequential damages.

WARRANTY

ES•2A™/ES•2SA™

2

BUNN Espress™

The notices on this brewer should be kept in good condition. Replace unreadable or damaged labels.

USER NOTICES

ES•2A™/ES•2SA™

This equipment is to be installed to

comply with the Basic Plumbing Code of

the Building Officials and Code

24247.0000

Administrators International, Inc. (BOCA)

and the Food Service Sanitation Manual

of the Food and Drug Administration (FDA).

00656.0000

CAUTION

HOT

Liquid-Steam-Surfaces

24246.0000

NOTICE

This “

Manual Fill Valve”

used during installation ONLY!

Watch the sight gage during use

and do not fill past normal line!

24245.0000

is to be

!

WARNING

Fill water tank before turning -on
thermostat or connecting appliance
to power source.
Use only on a properly protected
circuit capable of the rated load.

Electrically ground the chassis.
Follow national/local electrical codes.

Do not use near combustibles.

FAILURE TO COMPLY RISKS EQUIPMENT

DAMAGE, FIRE, OR SHOCK HAZARD

READ THE ENTIRE OPERATING MANUAL

BEFORE BUYING OR USING THIS PRODUCT

THIS APPLIANCE IS HEATED WHENEVER

CONNECTED TO A POWER SOURCE

00831.0000F 3/98 © 1988 BUNN-O-MATIC CORPORATION

00831.0000

3

BUNN Espress™

FEATURES

ES•2A™/ES•2SA™

HOT WATER RINSE DISPENSING TUBE AND STEAM DISPENSING TUBE

The ES•2A™ ES•2SA™are equipped with a hot water rinse dispensing tube and two steam dispensing
tubes. The Hot Water rinse dispensing tube is controlled by a knob centrally located on the front of the brewer.
The Steam dispensing tubes are controlled by knobs located on the left and right side of the brewer, right knob
controls the right side steam tube and the left knob controls the left side steam tube. They can be placed in
a continuous flow position by turning the knobs approximately half way around. All three outlet tubes possess
a rotary ball and socket type fitting for manual positioning.

WATER FEED TAP

This tap is of the automatically closing type. To introduce water into the tank, turn the control to the left
or right, indistinctly and hold it in position. When you release the control, it will automatically close.

LEVEL

Water level should never rise above the maximum level zone (+) and never descend below the minimum
level zone (-), as this may result in the heating element to melt. The optimum water level zone is indicated
with (N). In the models with electronic water level control for the tank, The optimum water level (N) is
maintained automatically.

Tank

The tank is made of copper plate, 1.5 mm thick and its components are made of cast or drop forged brass.
The tank cover is fixed to the tank by bolts with exterior nuts to facilitate its removal. The operating pressure
of the tank when in use should fluctuate between 0.9 and 1.2 bar as indicated on the tank pressure gauge with
no air inside the tank. Whenever the machine is pressurized, the pressure indicated on the gauge should be
checked to make sure it is the correct pressure. A pressure drop of 0.1 to 0.2 bar is considered normal. If
there is an abnormal amount of air in the tank, a very quick pressure drop will be observed on the pressure
gauge when one of the steam knobs are turned and steam is released. After a few moments, the real tank
pressure can be read on the gauge.

The difference of 0.9 to 1.2 bar, i.e. 0.3 bar, allows the effective exchange required to maintain the
optimum temperature in the units.

However, it is necessary that the installer, when installing the machine, decide at the installation site itself
through the performance of the corresponding tests, the adequate thermal point or correct pressure, keeping
in mind the working conditions of the machine, the hourly production rate required and the room temperature.

PUMP SET

The pump set is made up of a vane type, volumetric pump driven by a 0.25 HP single-phase motor,
supplied at 220 v-60 Hz.

If the water pressure exceeds 7-8 bar, a pressure reducer should be placed between the water line and
the pump set to reduce the output pressure of the water line to between 3-4 bar, which will be the pump set
water feed input pressure.

The output pressure of the pump of the pump set should be between 8-9 bar as a maximum. To check
this pressure, fill the cup of the coffee filter holder with pressed coffee and place it in any one of the infusion
units, press the continuous flow button and read the pressure on the feed line pressure gauge. If the gauge
does not show the previously mentioned values, the pump set’s delivery pressure should be adjusted. This
is done by loosening the screw to reduce pressure. Adjust said screw until the desired pressure is obtained.
The adjustment screw should only be turned very slowly.

NOTE: Pump motor needs to be 1/4 -1/5hp, 1725 rpm, 230 volts, carbonator style, U.L. recognized

4

BUNN Espress™

IMPORTANT: None of the high pressure pumps found on the market can operate without water for a

period of more than approximately ONE MINUTE, After one minute of dry operation the pump will seize and
become unserviceable.

Should water be shut off disconnect pump from power supply immediately.

FEATURES

ES•2A™/ES•2SA™

7

6

4

3

9

11

10

2

12

1

P-158

Group head (Espresso extraction chamber)

The group head-espresso extraction chamber is where the coffee infusion takes place. After extraction,
an electric pressure valve automatically discharges the accumulated pressure. When the coil (12) of the
electro-valve receives an electric current, causing the plunger (10) to move, thus closing the discharge valve
(2) and opening the water intake valve (9) allowing the water to pass towards the shower (4) through the
sprayer (3). This is when the brewing process (infusion) begins.

The bubbling effect is produced by an interchange between air, contained in a bubble formed in the
chamber, and water which progressively increases it’s pressure on that bubble. The mixture of air and water
produced then falls on coffee previously dampened by the infusion process. When the liquid extraction
process of the coffee is complete, excess pressure contained in the filter holder is then released through a
discharge valve (2). The atomizer (1) directs the water being discharged to the opening to avoid it’s splashing
outward.

WATER TREATMENT

It is essential to treat water entering the brewer to prevent lime scale build up in the boiler tank and other
plumbing. Recommended treatments are reverse osmosis or softening. Polyphosphate type treatment for
scale reduction, which works well on conventional coffee brewers, is not effective for espresso equipment.

5

BUNN Espress™

PLUMBING

ES•2A™/ES•2SA™

PLUMBING REQUIREMENTS

This brewer must be connected to a cold water system with an operating pressure between 20 and 90

psi. A shut-off valve should be installed before the pump. Install a pressure regulator in the line when the
pressure is greater than 90 psi. to reduce the pressure to 50 psi. The water inlet fitting is a 3/8 flare.

This equipment is to be installed to comply with the Basic Plumbing code of the Building Officials and Code

Administrators International, Inc. (BOCA) and the Food Service Sanitation Manual of the Food and Drug
Administration (FDA).

PLUMBING HOOK-UP

1. Flush the water line and securely attach it to the 3/8” flare fitting on the inlet side of the pump.

2. Connect one end of the braided hose (supplied) to the outlet side of the pump and the other end to
the water inlet fitting located under the drain tray of the brewer. This tray is removable. Do not
overtighten the fittings. Rubber gaskets are provided to be inserted into each end of the braided hose.

3. Turn on the water supply and check for leaks.

4. Plumbing diagram is shown below.

PUMP

OutletInlet

supply

line

3⁄8"

copper

Water supply line
(from strainer)

EasyClear filter

strainer

Insert washer

Braided hose

(inside brewer)

Inlet water fitting

Insert washer

brewer

P-138

pump

Important: Both filter and strainer must be hooked up in system.

6

P-139

BUNN Espress™

e

ELECTRICAL SPECIFICATIONS

This brewer requires a 2-wire grounded service rated 208 to 240 volts ac, 20 amp, single phase, 60

Hz.

ELECTRICAL HOOKUP

CAUTION: Improper installation will damage electronic components.

1. An electrician must provide electrical service as specified.

2. Using a voltmeter, check the voltage and color coding of each conductor at the electrical source.

3. The plug for the brewer is to be supplied by the installer.

4. Attach the plug to the brewer cordset as shown below:

ELECTRICAL

ES•2A™/ES•2SA™

L1

Red

240V

or

208V

L2

Blk

Grn

Gnd

5. Attach wires from pump cordset to terminal block located on pump motor as shown below:

Cover

Brn

Grn/Yel

Blu

Grommet

Compression

nut

From

brew

P-140

Blu

Terminal

block

Blk

P-141

NOTE: Wiring going into the terminal block must be tinned with solder to insure proper connection.
Warning: The brewer and pump must be electrically grounded. Do not assume that a plumbing line

will provide an adequate ground.

7

BUNN Espress™

INITIAL SETUP

ES•2A™/ES•2SA™

START-UP

Retighten the tank cover bolts, nuts, flat section strips, tank heaters, and the individual tank section lids
(at upper part of the tank). Fill the tank with water to the optimum water level zone (N) using the water feed
tap. In the models with and electronic water level control fill the tank to the minimum water level zone (-).

Connect the electrical system.

Turn on the toggle switch located on the base (left side bottom). The indicator lamp on the front of the
base (left side) will light up. When the toggle switch is turned on, in the model with an electronic water level
control, the electronic water level operation pilot light will light up, start the pump set and open the water inlet
valve (located inside the machine) introducing water into the tank until it reaches the optimum water level zone
(N).

NOTE: During the initial fill of the tank, if manual fill is not used and automatic is filling the tank,

the alarm condition will arise (during re-fill no water goes through the flowmeter). Refer to
“DOSAGE PULSEMETER MALFUNCTION ALARM” in the TROUBLE SHOOTING section
in this manual for further instruction.

When the water makes contact with the sensor probe, this will close the inlet valve, shut off the pump set,
and disconnect the pilot light.

While waiting for the machine to reach working pressure (tank pressure gauge), check and adjust the
pump set as on page 4.

When the tank and the pump pipes are filled, press the “continuous doses” push button on each set and
the pumping unit will immediately start injecting water into the corresponding tank section and tube leading
to the units until water begins to flow through them. This indicates that air has been bled from the hydraulic
circuit and the push-buttons can be pressed again to shut off the pump.

Before the tank pressure reaches 1.2 bar, air must be bled from inside the tank as described on page 4.

When the tank pressure gauge indicates 1.2 bar, the electrical pressure switch will disconnect. If this does
not occur at the mentioned pressure, adjust the pressure switch (page 29 figure 1), placed inside the machine
on the right side, using the inside adjustment screw. Tightening the screws lowers the tripping pressure and
vice-versa.

When the water in the individual tank sections and hydraulic circuit expands do to heating, the water
pressure gauge reading will exceed 8-9 bar working pressure, and when the pressure reaches 11 bar the
pressure release valve will open to release said pressure. If not, the inside nut (page 19 figure 13) must be
adjusted so that it discharges the pressure at an indicated pressure of 11 bar.

Place a dose of ground coffee (approx. 6 grams) in the cup of the filter-holder and after lightly tamping
the coffee, and wiping the rim free of any excess grounds, place the filter holder in the group head unit.

Turn on the push button control (red button) and all the mechanisms of the unit will begin operating, Let
it run about 30 seconds and observe the pump feed pressure.

8

BUNN Espress™

PROGRAMMING

ES•2A™/ES•2SA™

PUSH-BUTTON SET (AUTOMATICS ONLY)

This set is made up of five push-buttons (A,B,C,D, and E) and one pilot light (F). The A, B, C, and D push-buttons

are used to select the four possible water dosed and the E push-button is for continuous infusion injection.

The F pilot light indicates that the unit is operating. To Shut off the infusion injection process (STOP), press

any of the push-buttons (A, B, C, D, or E)

F

A

BC

D

E

PROGRAMMING DOSIFICATIONS

To change the factory set dosages, set the Program/Run toggle switch to the “Program” (right) position.

Depending on the dosage you wish to change (1 cup or 2 cups), fill the filter-holder with the proper amount
of ground coffee and place in the hand infusion unit of the machine. Press the corresponding dosage push­button and hold for approximately 3 seconds. The brew light will be flashing. Once the desired amount of
coffee is achieved press any of the dosage push-buttons to save the new setting in memory. Return the “Run/
Program” switch lever to the “Run” (left) position.

NOTES:1. This operation must be repeated for each dosage you wish to reprogram.

2. The push-buttons which were not reprogrammed will continue using the previous dosage
sets.

3. The “Continuous dosage” is not programmable.

PREINFUSION PROGRAMMING

Pre-infusion causes a non-programmable amount of brew water to be injected into the bed of coffee at
the beginning of the brew cycle; thus wetting the coffee, this is followed by a short delay, followed by the
programmed amount of dispense.

In order to check whether or not the pre-infusion has been turned on, turn the programming switch (14)
to the “Program” (right) position. If the pilot lamp (F) comes on, pre-infusion is on. To eliminate the pre­infusion, press the continuous dosage button (E) until the pilot lamp (F) turns off; then return the programming
switch to the “Run” position.

9