Dover unified brands groen DH-20, Руководство оператора

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9 OM-DH(T) DOMESTIC & (CE) INTERNATIONAL
JACKET VACUUM/REMOVING AIR FROM JACKET
When the kettle is cold, a positive pressure reading on the pressure/vacuum gauge
or a reading near zero indicates that there is air in the jacket. Air in the jacket acts
as an insulator, and slows kettle heating.
To remove air:
1. Start the unit. (Be sure there is water or product in the kettle when heating).
2. When the pressure/vacuum gauge reaches a positive pressure reading of five
PSI, release the trapped air and steam by pulling up the safety valve ring for
about five seconds. Repeat this step three or four times. Then let the pull ring
snap back into the closed position.
3. If there is little discharge (mostly air), and the pressure gauge drops back to
zero PSI, allow the pressure to build back to five PSI and repeat the procedure.
4. Once steam has been vented from the jacket as described in b, above, remove
the hot water from the kettle and replace it with cold. This will condense steam
in the kettle jacket, and the pressure gauge should show a reading of 20 to
30 inches mercury (Hg) below zero. If it does not, or if the vacuum is leaking
down, contact a Groen authorized service agency to correct the problem.
JACKET FILLING AND WATER TREATMENT
The jacket was charged at the factory with the proper amount of treated water.
You may need to restore this water, either because it was lost as venting steam or
by draining. If you are replacing water lost as steam, use distilled water. If you are
replacing treated water that ran out of the jacket, prepare more treated water as
directed in “Water Treatment Procedure,” below.
1. Allow the kettle to cool completely. The procedure will be easier with the kettle
under vacuum (pressure gauge reading below zero).
2. Make sure the fill valve is closed, and remove the square head pipe plug with
open-ended wrench.
3. Position a funnel in the opening and fill it with properly treated water.
4. Slowly open the fill valve to allow water to be sucked into the jacket. Quickly
close the valve to prevent air from entering.
5. Check water level in the jacket to ensure that it is between minimum and
maximum marks on glass or at the top of the sight glass port for models DH/
DHT-80.
6. Close the valve and reinstall the squarehead pipe plug.
7. Reestablish the jacket vacuum as described above, if the pressure gauge does
not show a negative reading of 20 to 30 inches mercury (Hg).
WATER TREATMENT PROCEDURE
1. Obtain water treatment compound and a pH test kit from your Groen Service
Agent.
2. Fill a mixing container with the measured amount of water required. Distilled
water is recommended.
Kettle Model Recommended Jacket Fill
DH-20, DHT-20 1-3/4 Gallons
DH/1-40, DHT/1-40 1-1/2 Gallons
DH-60, DHT-60 3 Gallons
DH-80, DHT-80 3 Gallons
3. Hang a strip of pH test paper on the rim of the container, with about 1 inch of
the strip below the surface of the water.
4. Measure the water treatment compound. One way to do this is to add the
compound from a measuring cup.
5. Stir the water continuously, while you slowly add treatment compound, until
the water has a pH between 10.5 and 11.5. Judge the pH by frequently
comparing the test strip color with the color chart provided in the test kit.
Caution: Do not add excess amount of treatment compound. Excess amount
could cause extensive corrosion.
6. As you add water to the jacket, check water level to ensure that it is between
minimum and maximum marks on glass or at the top of the sight glass port for
models DH/DHT-80. Stop adding water when it reaches the maximum marker
on the gauge.
7. Record the exact amounts of water and treatment compound needed. These
amounts may be used again, if the same water sources and compound are
used. However, it is best to check the pH each time treated water is prepared.
COMPONENT REPLACEMENT
When component replacement involves breaking a gas pipe connection, check the
new connection with soap solution or an appropriate leak detector. DO NOT USE A
FLAME TO TEST FOR LEAKS.
Internal wiring is marked as shown on the circuit schematic drawings (inside
control housing and in this manual). Be sure that new components are wired in the
same manner as old components. An examination of the circuit schematic shows
that the safety components are wired in series. In most cases, a faulty component
may be isolated with a jumper wire to verify that the component is faulty. If this
determination is made, contact a certified Groen Service Agency for assistance.
SEQUENCE OF OPERATION
The following “action-reaction” outline is provided to help understand how the
kettle works.
1. When the power switch is turned on, it starts the spark igniter and opens the
automatic valve for the pilot burner. The spark ignites a pilot flame, which
heats the sensor. The sensor then sends a signal to turn off the spark. The
flame thereafter acts as a standing pilot until the power is turned off.
2. If the pilot flame is not sensed within 90 seconds after spark begins, a timer
shuts down the entire operation. To attempt a second trial for ignition, turn
off the power switch. Check the gas supply valves and wait five minutes
before trying again by switching power on. If you cannot establish a pilot
flame in four tries, close all valves, turn off the power, and contact an
authorized Groen Service Agency.
3. When the operator sets a temperature on the controller, it causes the
automatic valve to admit gas to the main burner, where it is ignited by the
pilot flame. When the kettle reaches the set temperature, the controller
switch opens. This stops the signal to the gas control valve and shuts off
gas to the main burner. The pilot flame remains lit. When the kettle cools
below the set temperature, the controller switch closes and starts another
cycle. On and off cycling continues and maintains the kettle at the desired
temperature. This action is indicated by the Heat indicator light.
The kettle has the following safety features in addition to the 90-second ignition
timer:
1. Low water cutoff relay that will shut off gas supplies to all burners until the
jacket water level is corrected.
2. High limit pressure switch, set to open at about 46 PSI and to shut down the
burners until jacket pressure is decreased.
3. Pressure relief valve, which will release steam if jacket pressure exceeds 50
PSI.
4. Tilt switch, which shuts off all burners when the kettle is tilted.
5. Gas pressure regulator built into the gas control valve.