Page 1
Service instructions
Boiling kettle
Unit Type of energy Unit type Model
Quick boiling kettle
(round)
Quick boiling kettle
(rectangular)
Translation from the original document • 2022802B--ASDE-A • 10/20/2017
Electric Pedestal unit Optima 850
Optima 750
2022802B--ASAE-A en-US
Page 2
Copyright
All rights to text, graphics and pictures in this documentation are held by MKN Maschinenfabrik Kurt
Neubauer GmbH & Co. KG. Distribution or duplication is exclusively permissible subject to a written
consent of MKN.
Copyright by MKN Maschinenfabrik Kurt Neubauer GmbH & Co. KG
Manufacturer
Copyright by MKN Maschinenfabrik Kurt Neubauer GmbH & Co. KG
Halberstaedter Strasse 2a
D-38300 Wolfenbuettel
Telephone 0 53 31 / 89-0
Telefax 0 53 31 / 89-280
2 Service instructions
Page 3
Directory of contents
1Introduction......................................................................... 5
1.1About this manual ............................................................................ 5
1.2Warranty............................................................................................ 5
2Safety instructions ............................................................. 6
3Operating and display elements ....................................... 7
4Opening/closing the unit ................................................... 8
4.1Removing and installing the drain valve........................................ 8
4.1.1Removing the drain valve.......................................................................... 8
4.1.2Installing the drain valve............................................................................ 8
4.2Removing and installing the front panel........................................ 9
4.2.1Removing the front panel .......................................................................... 9
4.2.2Installing the front panel ............................................................................ 9
5Functional overview......................................................... 10
5.1Component overview ..................................................................... 10
5.1.1Round version ......................................................................................... 10
5.1.2Rectangular version ................................................................................ 12
5.2Circuit diagram overview............................................................... 14
5.2.1Control circuit (round version) ................................................................. 14
5.2.2Heating circuit (round version) ................................................................ 15
5.2.3Control circuit (rectangular version) ........................................................ 16
5.2.4Heating circuit (rectangular version)........................................................ 17
5.3Power consumptions ..................................................................... 18
6Heating .............................................................................. 19
6.1Vapro heating system .................................................................... 19
6.2Arrangement of the heating elements.......................................... 20
7Steam generator ............................................................... 21
7.1Filling............................................................................................... 21
7.2Steam generator heating process ................................................ 22
7.3Emptying the steam generator...................................................... 23
8Assembly information...................................................... 25
8.1Kettle drain valve............................................................................ 25
8.1.1Removing / Mounting .............................................................................. 25
8.1.2Information on care ................................................................................. 25
8.1.3Replacing the seals ................................................................................. 26
8.1.4Overview of drain valve and maintenance kit.......................................... 26
8.2Level controller............................................................................... 27
8.3Steam generator heating elements............................................... 28
9Troubleshooting ............................................................... 29
2022802B--ASAE-A
3Service instructions
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Directory of contents
9.1Steam generator ............................................................................. 29
9.1.1Overfilling ................................................................................................ 29
9.1.2The yellow indicator light on the operating panel is on............................ 31
9.2Insufficient heat output / no pressure buildup ............................ 33
9.3No function...................................................................................... 34
10Maintenance.................................................................... 36
10.1Lid hinge ....................................................................................... 36
4 Service instructions
2022802B--ASAE-A
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1 Introduction
1.1 About this manual
Target group Target group for this service manual is qualified personnel who are
Figures All figures in this service manual are intended as examples.
Spare parts To ensure the reliability of the unit and the individual components, it is
Introduction
This service manual contains information needed by the service
technician for professional and correct fault isolation, repair and
maintenance of the unit. The service technician must also observe
the contents of the installation instructions and the user manual.
familiar with the technical functioning and operation of the unit.
Discrepancies can arise between this and the actual unit.
essential that only genuine OEM parts be used.
Spare parts can be identified exactly with the aid of the online
database.
1.2 Warranty
The warranty is void and safety is no longer assured in the event of:
• Modifications or technical changes to the unit,
• Improper use,
• Incorrect startup, operation or maintenance of the unit,
• Problems resulting from failure to observe these instructions.
2022802B--ASAE-A
5Service instructions
Page 6
Safety instructions
2 Safety instructions
For servicing tasks, the service technician must be familiar with and
observe regional regulations.
In addition, the notes in the service manual must be observed.
DANGER
Danger to life due to electric current
Disconnect power prior to performing gas and electrical work.
• Disconnect unit from the mains supply and secure it against
• Check to ensure absence of voltage.
restart.
6 Service instructions
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3 Operating and display elements
-0.5
-1.0
1.0
0.5
0
1.5
2
3
0
1
30°C
50
80
100
a b c d e
Image: Operating panel of boiling kettle
a
Pressure
c
Temperature
e
Output
display b Process water / malfunction
operating knob d
operating knob
Operating and display elements
indicator light
Heating
indicator light
2022802B--ASAE-A
7Service instructions
Page 8
Opening/closing the unit
4 Opening/closing the unit
4.1 Removing and installing the drain valve
4.1.1 Removing the drain valve
Image: Removing the drain valve
Prerequisite Unit switched off.
Kettle emptied.
1. Undo the screw on the drain valve.
2. Turn the drain valve about 30° clockwise and remove it.
4.1.2 Installing the drain valve
Image: Installing the drain valve
1. Turn the position of the drain valve about 30° clockwise and place
it on the spigot.
2. Push the drain valve onto the connection.
3. Turn the position of the drain valve about 30° counterclockwise.
4. Align the drain valve vertically.
5. Thread screw into the drain valve.
8 Service instructions
2022802B--ASAE-A
Page 9
4.2 Removing and installing the front panel
a
b
c
d
4.2.1 Removing the front panel
Opening/closing the unit
Image: Removing the front panel
Prerequisite Unit dead
Drain valve removed
1. Undo screws on the bottom of the front panel.
2. Carefully pull the bottom of the front panel forwards and then
3. Check the seal.
4. Install seal.
4.2.2 Installing the front panel
Prerequisite Unit dead
Drain valve removed
Seal on front panel intact
a Operating panel b Front panel
c Seal d Screw
downwards.
Seal not intact
Remove seal
1. Press seal onto front panel.
2. Carefully slide the front panel behind the edge of the operating
panel from below.
3. Press the front panel in at the bottom.
4. Check that the front panel is in contact on all sides.
5. Screw in the screws on the bottom.
Make sure that no wires are pinched.
2022802B--ASAE-A
9Service instructions
Page 10
Functional overview
a b c d e g h
f i
5 Functional overview
5.1 Component overview
5.1.1 Round version
Image: Component overview, upper region
a Pressure regulator b Manometer
c Vacuum breaker valve d Indicator light (yellow)
e Safety temperature limiter
(thermostat)
g Thermostat h Indicator light (white)
i Main switch
f Position of thermostat sensor
10 Service instructions
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Page 11
Functional overview
a b c d e
f g h i
j
k
l
m
n
Image: Component overview of base for 100-liter boiling kettle by way of example. The steam generation equipment varies
with the size of the unit
b Contactor K2 with auxiliary
contact K2.2 or with contactor K3
temperature limiter)
2022802B--ASAE-A
a Steam generator with heating
elements
c Contactor K1 d Level-detecting electronicss
e Fuse 6.3 A f Thermostat sensor (safety
g Pilot heating element h Thermal switch
i Fill level electrode j Bleeder valve
k Pressure relief valve l Solenoid valve (filling)
m Steam generator drain valve n Check valve
11Service instructions
Page 12
Functional overview
a b c d e f g
5.1.2 Rectangular version
Image: Component overview, upper region
a Manometer b Pressure regulator
c Indicator light (yellow) d Safety temperature limiter
(thermostat)
e Thermostat f Indicator light (white)
g Main switch
12 Service instructions
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Page 13
Functional overview
a b c d e f g h i j
k
l m n
Image: Component overview of base for size 1 boiling kettle by way of example. The steam generation equipment varies
with the size of the unit
a Steam generator drain valve b Contactor K1. Contactor K4
additionally, depending on version
c Contactor K2 with auxiliary
contact K2.2 or with contactor K3
e Fuse 6.3 A f Level-detecting electronicss
g Steam generator with heating
elements
i Thermal switch j Fill level electrode
k Bleeder valve l Check valve
m Solenoid valve (filling) n Pressure relief valve
d Pilot heating element with
thermostat sensor (safety
temperature limiter)
h Position of thermostat sensor
2022802B--ASAE-A
13Service instructions
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Functional overview
PE
N
L2L1L3
X1
max
B2
N
B3
B4
B1
2
1
S2
K1 K2
A1
A2
A1
H1
A
B
C
D
PE
∗
A2
X1
3
S1
32
A D
E6
1 4
B5
H2
F2 X1
Wasser
ge (R)
Betrieb
gn (U)
B1
B2
B3
B1
15
16 18
A1
A2
P1 P2 P3
1 2 3
A1
A2
A1
K3
5.2 Circuit diagram overview
5.2.1 Control circuit (round version)
S1 Main switch
A1 Level-detecting electronicss B1 Thermostat
B2 Solenoid valve B3 Level-detecting electrode
B4 Thermal switch 90°C B5 Safety thermostat
E6 Pilot heating element F2 Fuse, 6.3 AT
H1 Indicator light (white) H2 Indicator light (yellow)
K1 Heating contactor (level 1 & 3) K2 Heating contactor (level 2 & 3)
K3 Heating contactor (level 2 & 3).
Only on kettle sizes 100 & 150
liters
S2 Pressure regulator * Jumper on unit version with
preparation for power optimization
14 Service instructions
2022802B--ASAE-A
Page 15
5.2.2 Heating circuit (round version)
B
D
A
C
B
D
A
C
B
D
A
C
B
D
A
C
1
2 3
4
5
19
20
21 22
23
24
25
K1 K2
L1L2L3
L3
L2
L1
101112
13
141516
17
L1
L2
18
K3
L3
6 7
8
9
B
D
A
C
E1 E2 E3 E4 E5
150L
L1
L1
L2L2L3
L3NPE
X1
X2:D
26
27
28
29
67
K1
L2L3L3
101112
13
L1
L2L2L3
L3NPE
X1
X2:D
67
L2
B
D
A
C
B
D
A
C
B
D
A
C
E1 E2 E3
K2
L1
141516
17
L1L2L3
123
4
5
6
7
8
19
20
21
22
60 Liter 100 & 150Liter
Functional overview
E1 – E5 Heating elements K1 Heating contactor
K2 Heating contactor
(level 2 & 3)
(level 1 & 3)
K3 Heating contactor (level 2 & 3).
Only for unit sizes 100 and 150
liters
2022802B--ASAE-A
15Service instructions
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Functional overview
S1
-F1
2 3 4
P2 P3 P4P1
1
-X2:L1
K1
A1
A2
A1
A2
K2
A2
A1
A2
A1
K4 K3
H1
ws
H2
ge
B5
B1
max
B3
bl
B4
2
1
S2
3
P
A
B
C
X3
E8
D
A
1
2
PE
D
-A1:A2
-B2:N
-H1:N
-X3:N
-K1:A2
W a s se r
g e ( R )
B e t r ie b
g n ( U )
50
100%
t=2s
15
16 182526 28
A1
A2
B1
B2
B3
A1
6453
PE
A1:A2
66
40
41
42
43
44
45
46
47 55
48
60
61
62
32 33
52 34
37
37
38
56
39
63
64
35
36
52
49
40
54
434856
63
65
66
50
58
44
31
65
B2
60
N
51
5.2.3 Control circuit (rectangular version)
A1 Level-detecting electronicss B1 Thermostat
B2 Solenoid valve B3 Level-detecting electrode
B4 Thermal switch 90°C B5 Safety thermostat
E8 Pilot heating element F1 Fuse, 6.3 AT
H1 Indicator light (white) H2 Indicator light (yellow)
K1 Heating contactor (level 1 & 3) K2 Heating contactor (level 2 & 3)
K3 Heating contactor (level 2 & 3) K4 Heating contactor (level 1 & 3)
S1 Main switch S2 Pressure regulator
* Jumper on unit version with
preparation for power optimization
Only on unit size 3
16 Service instructions
2022802B--ASAE-A
Page 17
5.2.4 Heating circuit (rectangular version)
B
D
A
C
B
D
A
C
B
A
E2 E3 E4
L2L3L3
B
D
A
C
E1
L1
K1
D
C
L2L3L3
K1
L1
B
D
A
C
B
A
E2 E4
L1
L2
D
C
B
D
A
C
E6
B
D
A
C
B
D
A
C
B
D
A
C
B
D
A
C
E7E1 E3 E5
L1
L2
1
2
3 4
L1
L1
X2
L2L2L3L3PE
K2
L2
L1
5
6 7
8
L1
L2
K3
9
L3
B
D
A
C
B
D
A
C
B
D
A
C
B
D
A
C
19
20
21 22
23
24
25
B
D
A
C
E1 E2 E3 E4 E5
150L
26
27
28
29
L1
L2
L1
L2
L3
L3
K3
L3
L3
K1 K4 K2
1
2
3 4
5
6
7
8
9
10
11
12
13 14 15 16 17 18
19
20
21
22
23
24
1
2
3 4
5
6 7
8 9
101112
13
141516
17
18
101112
13
141516
17
18
19
20
21 22
23
24
25
85
86
87 88
89
90
91
92
93
94 95
96
97
9899100
K2
L2
L1L1L2
K3
L3
Größe 1 / size 1
Größe 2 / size 2
Größe 3 / size 3
Functional overview
2022802B--ASAE-A
E1 –E7 Heating elements K1, K4 Heating contactor
(level 1 & 3)
K2 – K3 Heating contactor
On older versions: K3 = K2.2; K4 = K1.2
(level 2 & 3)
17Service instructions
Page 18
Functional overview
5.3 Power consumptions
Type Output Power consumption (400 V)
L1 L2 L3
60 liters, round 15.8 kW 25.1 A 21.7 A 21.7 A
100 liters, round 20.8 kW 30.7 A 32.5 A 27.2 A
150 liters, round 25.8 kW 36 A 38 A 38 A
Size 1,
rectangular (125
liters)
Size 2,
rectangular (195
liters)
Size 3,
rectangular (285
liters)
20.8 kW 30.7 A 32.5 A 27.2 A
25.8 kW 36 A 38 A 38 A
35.8 kW 52.3 A 54.1 A 48.8 A
18 Service instructions
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6 Heating
a
b
c
d
e
g
h
i
j
k
l
f
m
n
6.1 Vapro heating system
Heating
a Manometer for pressure
measurement
c Fill level electrode d Solenoid valve (filling)
e Heating f Steam generator drain valve
g Pressure regulator h Temperature operating knob
i Temperature sensor j Drain valve
k Steam generator l Process water
m Double-walled kettle lid n Chrome nickel steel container,
b Pressure relief valve
deep-drawn from one piece
2022802B--ASAE-A
19Service instructions
Page 20
Heating
bcbcba
60 Liter 100 Liter
150 Liter
a b b b bc
a b b b bb
C D
BA
C D
BA
C D
E2 E3
BA
C D
E4
D
BA
E1
A
E8
BA
C D
BA
C D
BA
C D
E2 E3
A
E4
E1
A
D
E8
B
C D
BA
CE5D
BA
C D
BA
C D
E2 E3
BA
C D
BA
C D
BA
C D
E5E4 E6 E7
BA
C D
D
BA
C D
E1
E8
A
Größe 1 / size 1
Größe 2 / size 2
Größe 3 / size 3
a b b b b
ab b b b b b b
a b b b b b
6.2 Arrangement of the heating elements
Round boiling kettle
Rectangular boiling kettle
a Pilot heating element b Heating element
c Blind plug
20 Service instructions
2022802B--ASAE-A
Page 21
Steam generator
7 Steam generator
7.1 Filling
Description of operation The description refers to a cold unit with an empty steam generator.
Switching on the unit The level controller A1 is supplied continuously with 230 V. The green
operating LED is illuminated.
Steam generator filling
Turn the
The number of contactors depends on the unit model.
The unit is on and cold.
Output
Position 1: Contactors K1 / K4 are energized. The heating
output is approx. 20%.
Position 2: Contactors K2 / K3 are energized. The heating
output is approx. 40%.
Position 3: Contactors K1 to K4 are energized. The heating
output is 100%.
Level controller, terminal 15, is supplied with 230 V.
operating knob to the desired position.
The yellow indicator light and the yellow LED on the level-
detecting electronics are on.
Solenoid valve B2 is energized by the level-detecting
electronics A1.
Fill the steam generator to the maximum fill level.
Filling is stopped when the level-detecting electrode senses
water.
The yellow indicator light switches off.
Above a temperature of 90°C, filling is prevented by the thermal
switch, which shorts the level-detecting electrode to ground.
2022802B--ASAE-A
21Service instructions
Page 22
Steam generator
7.2 Steam generator heating process
Heating process
Unit is on and the steam generator is filled.
The water in the steam generator is heated.
The heated air-steam mixture is directed into the double shell
of the kettle.
Condensate that forms is directed into the steam generator via
the condensate line.
The steam generated displaces the air above the vacuum
breaker valve.
The bleeder valve opens and closes during heating. The valve
remains closed permanently during operation.
The pressure in the steam generator is displayed on the
manometer.
The operating pressure is 0.6 - 0.8 bar.
At a pressure of 1.0 bar, the pressure relief valve opens.
The check valve prevents flow of water back into the on-site
water supply.
At a vacuum of -0.5 bar, the vacuum breaker valve opens (only
on round kettles).
22 Service instructions
2022802B--ASAE-A
Page 23
7.3 Emptying the steam generator
a b
Description It is necessary to empty the steam generator for frost-proof storage /
transport. In addition, the water filling is checked by means of a
measurement of the content. This requires collecting and measuring
the amount of water contained.
Overview
Image: Drain valve on the rectangular boiling kettle
Steam generator
Preparations
Emptying the steam
generator
Overview of steam
generator volumes
a Hose connection b Drain valve
De-energize unit.
Remove the drain valve.
Remove the front panel.
DANGER
Risk of personal injury and property damage from escaping
steam
• Before opening the drain valve, make sure that the steam
generator has cooled.
Attach hose to water connection.
Open the drain valve.
The water drains out of the steam generator.
Close the valve after the steam generator is emptied.
Size Steam generator volume
60 liters, round 7 liters
2022802B--ASAE-A
100 liters, round 7 liters
150 liters, round 7 liters
Size 1, rectangular (125 liters) 9.5 liters
Size 2, rectangular (195 liters) 12.5 liters
Size 3, rectangular (285 liters) 16.5 liters
23Service instructions
Page 24
Steam generator
If the volume is different, underfilling or overfilling has occurred.
Troubleshoot the situation.
24 Service instructions
2022802B--ASAE-A
Page 25
8 Assembly information
10°
8.1 Kettle drain valve
8.1.1 Removing / Mounting
Assembly information
Disassembly
Assembly
Loosen the fastening screw the drain valve.
Pull the drain valve off the connection port.
Lightly grease the connection port.
Push on the valve.
Fasten with the screw.
8.1.2 Information on care
Do not use cleaners with a high chloride or acid content. Do not use
high-pressure cleaning equipment. Lightly grease O-rings and pistons
after every cleaning. Use special valve and fitting grease when
relubricating.
2022802B--ASAE-A
25Service instructions
Page 26
Assembly information
a
8.1.3 Replacing the seals
Installation instructions
A maintenance kit that includes all seals and a tube of grease is
available for maintenance.
If individual seals are worn, always change all of them together.
When changing them, ensure that the guide grooves are not
damaged.
Remove damaged or worn seals with a pointed knife.
Always grease O-rings before installing them.
In order to prevent leaks through twisting, first hook the diagonal
seal onto the top of the piston, do not push it on from below.
Insert the new seals (a).
Grease the piston again prior to installation.
Image: Installing the diagonal O-ring
8.1.4 Overview of drain valve and maintenance kit
Description MKN No. MKN No. for
Kettle drain valve DN
42 (1 ½ ")
Kettle drain valve DN
50 (2 ")
Replacement
maintenance kit
10015499 10015505 201880 &
10015500 10015506 201794 &
for MKN No.
10014006
10014007
26 Service instructions
2022802B--ASAE-A
Page 27
8.2 Level controller
t= 2s
100%
50
Assembly information
Preparations
Disassembly
Assembly
De-energize unit.
Remove the front panel. On side arm units, remove the front panel
on the right.
Detach lines from components and label if necessary.
Remove the component.
Make the settings on the new component.
Image: Settings for level controller #203419
Install the level controller.
2022802B--ASAE-A
27Service instructions
Page 28
Assembly information
a b dc
8.3 Steam generator heating elements
Preparations
Overview
De-energize unit.
Open the front panel and empty the steam generator.
If necessary, remove the protective covers in front of the steam
generator.
Image: Heating element replacement on pilot heater by way of example
a Nut b Mounting clamp
c Heating element d Power supply
Disassembly
Remove electrical connections.
Loosen nut and pull out heating element.
For pilot heating element only: Disassemble fasteners from
thermostat sensor and remove them.
Assembly Reassembly is carried out in reverse order
The torque should be 5 Nm.
Replace bent and damaged cable lugs.
28 Service instructions
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Page 29
9 Troubleshooting
9.1 Steam generator
9.1.1 Overfilling
Description The steam generator is constantly overfilled. The water can always
Prerequisite Correct settings on the level-detecting electronics (see „8.2 Level
Troubleshooting
The steam generator will make frequent loud "banging sounds"
during heating if it is overfilled. In addition, bursts of steam and
water will emerge from the bleeder valve. Check the amount of
water in the steam generator by draining some.
Severe overfilling
emerge from the hose coming from the bleeder valve.
controller‟, Page 27).
The conductivity of the water must be at least 10 μS. If necessary,
use a conductivity meter to measure the process water.
The unit has cooled down.
Troubleshooting Open the front panel and empty the steam generator.
Level-detecting electrode
Solenoid valve for filling The solenoid valve for filling does not close completely or is
Level-detecting
electronicss
Remove the level-detecting electrode and check for calcium
deposits. Turn the level-detecting electrode only by means of the
hex in order to prevent damaging it.
Remove calcium deposits from the level-detecting electrode or
replace it.
energized continuously.
The solenoid valve may only be energized via terminal 18 when
the yellow LED on the level-detecting electronics is illuminated. If
the solenoid valve is energized continuously, the level controller is
defective.
Check the solenoid valve for proper operation (leaks). Replace if
necessary. Make sure that the sieve is present at the intake of the
valve and is clean.
Terminal B1 is not connected to ground.
Make sure that B1 is connected to ground.
There is a fault in the level-detecting electronics.
2022802B--ASAE-A
Replace the level-detecting electronics.
29Service instructions
Page 30
Troubleshooting
Gradual overfilling
Troubleshooting Open the front panel and empty the steam generator.
Prerequisite The unit has cooled down.
Solenoid valve for filling The solenoid valve for filling does not close completely.
Check the solenoid valve for proper operation (leaks). Replace if
necessary.
Make sure that the sieve is present at the intake of the valve
and is clean.
30 Service instructions
2022802B--ASAE-A
Page 31
9.1.2 The yellow indicator light on the operating panel is on
B1
2
1
S2
H1
A
B
C
D
3
1
B5
H2
Wasser
gelb/yellow
Betrieb
grün/green
B1
B2
B3
B1
A1
A B H4H3
C
PE
N
L1
X1
B2
N
B1
2
1
S2
H1
A
B
C
D
∗
3
S1
1
4
B5
H2
F2 X1
Wasser
gelb/yellow
Betrieb
grün/green
B1
B2
B3
B1
15
16 18
A1
A2
P1 P2 P3
1 2 3
A1
The yellow indicator light comes on in the following conditions:
• Steam generator filling. There is no fault.
• The safety temperature limiter has tripped. It will reset
automatically when the temperature is below 185°C. The amount
of water in the steam generator is insufficient.
Prerequisite Correct settings on the level-detecting electronics (see „8.2 Level
controller‟, Page 27).
The unit has cooled down.
Overview
Troubleshooting
2022802B--ASAE-A
H3 LED yellow. Filling required H4 LED green. Power supply
Troubleshooting Open the front panel.
Actuate the main switch and thermostat.
Overfilling The yellow LED H3 on the level-detecting electronics is on.
The conductivity of the water must be at least 10 μS/cm. If
necessary, use a conductivity meter to measure the process
water.
Remove the level-detecting electrode and check for calcium
deposits.
Empty the steam generator (see „7.3 Emptying the steam
generator‟, Page 23).
The connection between the level-detecting electronics (terminal
B1) and ground is interrupted
Remove calcium deposits from the level-detecting electrode or
replace it.
Check the connection.
31Service instructions
Page 32
Troubleshooting
Level-detecting electronics defective.
Replace component.
The yellow LED H3 on the level-detecting electronics is off.
The solenoid valve for filling does not close completely.
Check the solenoid valve for proper operation (leaks). Replace
if necessary. Make sure that the sieve is present at the intake
of the valve and is clean.
Check the level-detecting electronics.
No filling The yellow LED H3 on the level-detecting electronics is on.
Ensure that water is being supplied according to installation
instructions.
Check the level-detecting electronics.
Measure the voltage at measuring point B (A1, terminal 18). It
must be 230 V.
No voltage present = Replace the level-detecting electronics.
Voltage present = Replace the solenoid valve.
The yellow LED H3 on the level-detecting electronics is off.
Check the thermal switch for proper operation.
With the power disconnected, check the component for proper
operation. The contact must remain open up to 90°C. A closed
contact prevents filling. If necessary, disconnect the cable
coming from the level-detecting electrode when cold. If filling
then takes place, there is a fault in the thermal switch.
Check the level-detecting electronics.
Ensure that power is supplied to terminals A1 and A2.
The green LED on the level-detecting electronics is on.
Measure the voltage at measuring point A (A1, terminal 16). It
must be 230 V.
No voltage present = Replace the level-detecting electronics.
Voltage present = Continue troubleshooting.
Check the safety temperature limiter only when it is cool.
Measure the voltage at measuring point C. It must be 230 V.
No voltage present = Replace the safety temperature limiter.
32 Service instructions
2022802B--ASAE-A
Page 33
9.2 Insufficient heat output / no pressure buildup
Description The boiling kettle does not heat or the heat output is insufficient; no
pressure builds up in the double shell.
Troubleshooting
Overview of power
consumption
Type Output level Power consumption (400 V)
L1 L2 L3
60 liters, round Level 1 - 9.8 A 6.3 A
Level 2 6.3 A 14.3 A 6.3 A
Level 3 21.7 A 25.1 A 21.7 A
100 liters, round
Size 1, rectangular (125
liters)
150 liters, round
Size 2, rectangular (195
liters)
Size 3, rectangular (285
liters)
Level 1 3.5 A 9.4 A 9.4 A
Level 2 15.6 A 16.5 A 6.3 A
Level 3 30.7 A 32.5 A 27.2 A
Level 1 3.5 A 9.4 A 9.4 A
Level 2 15.6 A 15.6 A 6.3 A
Level 3 36 A 38 A 38 A
Level 1 12.5 A 16.2 A 9.4 A
Level 2 18.7 A 27.1 A 15.6 A
Level 3 52.3 A 54.1 A 48.8 A
2022802B--ASAE-A
Troubleshooting Electrical
Open the front panel.
Check on-site power supply.
Fill the boiling kettle.
Set thermostat to the maximum value. Set main switch to level 1
and check the power consumption.
The white indicator light is on.
Contactor K1 is energized (depending on version, contactor K4
additionally, if installed).
No power consumption = Check main switch, contactor and
heating elements for proper operation.
Insufficient power consumption = At least one heating element
is defective. Also check whether the contactor switches all
phases.
Power consumption is OK = Check sensor location of
thermostat on the double shell. "Banging noises" indicate
overfilling (see „9.1.1.1 Severe overfilling‟, Page 29).
Set thermostat to the maximum value. Set main switch to level 2
and repeat troubleshooting as for level 1. In this case, contactor
K2 is energized (depending on the version, contactor K3
additionally, is installed).
33Service instructions
Page 34
Troubleshooting
If a contactor is is defective, overheating of the steam generator
may result. This is indicated by temper colors on the steam
generator. In this case, check the safety valve and replace if
necessary.
Mechanical (no pressure buildup)
Make sure the manometer functions properly.
Pressure regulator
Heat unit with an empty kettle and start unit at maximum output
level.
At approx. 0.8 bar gauge pressure, the pressure regulator must
shut off.
At approx. 0.6 bar, the pressure regulator must reactivate.
Bleeder valve
Heat unit with an empty kettle and start unit at maximum output
level.
After approx. 10 minutes, the bleeder valve must close. This
can be recognized by reduced water discharge from the
condensate outlet.
A pressure increase is observed on the manometer.
If steam or water continues to emerge from the condensate
outlet, the valve is leaking.
Replace a leaking valve.
Safety valve
CAUTION
Risk of scalding from escaping steam
Only carry out inspection of a unit that has cooled down.
Actuate the red lever on the safety valve.
The valve stem must move easily.
If the valve stem sticks, possibly because of calcium deposits or
exposure to excessively high temperature, the safety valve must
be replaced.
9.3 No function
Description The boiling kettle does not switch on and does not function. The white
indicator light H1 on the operating panel is off.
Troubleshooting
34 Service instructions
Open the front panel.
Check on-site power supply.
2022802B--ASAE-A
Page 35
Troubleshooting
Check fuses F1 and F2 in the unit.
If a fuse is blown, there is a short-circuit at a contactor, pilot
heater, solenoid valve or the level-detecting electronics. With
the power disconnected, check components for a short-circuit
with a meter.
The fuse is not blown and the green LED on the level-detecting
electronics is on. Continue troubleshooting.
Check the terminal for connection of a power optimization system.
A jumper must be placed between terminals B and C when not
in use.
If a power optimization system is being used, disconnect it and
install a jumper. There may be an external fault.
With the power disconnected, check the thermostat for proper
operation (continuity).
No continuity when connected to power = Component is
defective.
With the power disconnected, check the pressure regulator for
proper operation (continuity between terminals 1 and 2).
No continuity = Component defective.
Check main switch for proper operation.
Position 1 = Voltage at terminals P1, P2, 1, 2.
Position 2 = Voltage at terminals P1, P3, 1, 3.
Position 3 = Voltage at terminals P1, P2, P3, 1, 2, 3.
2022802B--ASAE-A
35Service instructions
Page 36
Maintenance
a b c
10 Maintenance
10.1 Lid hinge
Prerequisite Required tool: Wrench, 24mm.
Lubricating the lid hinge
To maintain ease of movement, regularly lubricate the lid hinge
with food-grade grease.
a Cap nut c Cap nut
b Lubricating nipple
Close the lid.
Remove the cap nuts.
Using a grease gun, press grease into the lubricating nipple.
Reinstall the cap nuts.
Open and close the lid several times.
This distributes the grease in the lid hinge.
36 Service instructions
2022802B--ASAE-A
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