BANDELIN Sonorex Super RK 31 Operating instructions

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55 years of experience in ultrasound technology
Service Instructions
3 Compact Ultrasonic Cleaning Units
Type
230 V 115 V
RK 31, RK 31 H RK 31, RK 31 H
RK 52, RK 52 H, RK 52 CH RK 52, RK 52 H, RK 52 CH
RK 100, RK 100 H, RK 100 SH, RK 102 H, RK 102 CH RK 100, RK 100 H, RK 100 SH, RK 102 H, RK 102 CH
TK 100, TK 100 H TK 100 H
RK 103 H, RK 103 CH RK 103 H, RK 103 CH
RK 106 RK 106
RK 156, RK 156 BH RK 156, RK 156 BH
RK 158 S
RK 170, RK 170 H
RK 255, RK 255 H, RK 255 CH RK 255, RK 255 H, RK 255 CH
RK 510, RK 510 H RK 510, RK 510 H
RK 512 H, RK 512 CH RK 512 H, RK 512 CH
RK 513 RK 513
RK 514, RK 514 H, RK 514 BH RK 514 H, RK 514 BH
RK 515 CH RK 515 CH
RK 517 H
RK 1028, RK 1028 H, RK 1028 BH, RK 1028 C,
RK 1028 CH RK 1028, RK 1028 H, RK 1028 BH, RK 1028 C, RK 1028 CH
RK 1029, RK 1029 H
RK 1040 RK 1040
RK 1050, RK 1050 H, RK 1050 BH, RK 1050 CH RK 1050, RK 1050 CH
1217u e/2008-09

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Contents
1 Overview of possible faults, causes and remedies ................................................................. 3
2 Repair advices ........................................................................................................................ 5
3 Disassembly of unit ................................................................................................................. 5
4 Repairs ................................................................................................................................... 6
4. 1 Check of transistors ............................................................................................................. 6
4. 2 Exchange of transistors ....................................................................................................... 6
4. 2. 1 Transistors in insulated case (Isowatt 218) ............................................................................ 6
4. 2. 2 Transistors in plastic case (TO-220) and synthetic material press-on plate ........................... 7
4. 2. 3 Transistors in metal case (TO-3) ............................................................................................ 7
4. 2. 4 Transistor in plastic case and metal clip(s) ............................................................................. 8
4. 3 Exchanging the generator PCB including the base plate ................................................. 9
4. 3. 1 With original generator of older type and supply of a replacement generator without ICs ..... 9
4. 3. 2 With original generator of older type (G) and supply of a replacement generator (FH1-2)
with ICs ................................................................................................................................... 9
4. 4 Repairing the heating ......................................................................................................... 11
4. 4. 1 Checking the heating elements and data ............................................................................. 11
4. 4. 2 Separating the oscillating tub from the housing .................................................................... 12
4. 4. 2. 1 Disassembly of screwed drain .............................................................................................. 12
4. 4. 2. 2 Disassembly of welded drain ................................................................................................ 12
4. 4. 3 Exchanging a defective heating ............................................................................................ 13
4. 4. 4 Exchanging the thermostat of dry-run protector ................................................................... 13
4. 4. 5. Checking the regulating thermostat ...................................................................................... 13
4. 4. 6. Exchanging the regulating thermostat .................................................................................. 14
4. 4. 7 Assembly of oscillating tub and housing ............................................................................... 14
4. 4. 8 Replacement parts for the heating ........................................................................................ 15
4. 5 Repair of oscillating systems ............................................................................................ 16
4. 5. 1 Disassembly of defective oscillating systems ....................................................................... 16
4. 5. 2 Assembly of oscillating systems ........................................................................................... 16
4. 5. 2. 1 Oscillating systems with two PZT-rings ................................................................................ 17
4. 5. 2. 2 Marking of PZT-rings ............................................................................................................ 17
4. 5. 2. 3 Oscillating systems with one PZT-rings ................................................................................ 18
4. 6 Exchanging the timer ......................................................................................................... 19
4. 7 Exchanging the ventilator of RK 1050 BH ........................................................................ 19
4. 8 Exchanging the pilot lamps ............................................................................................... 20
5 Re-starting the unit ............................................................................................................... 20
6 Data for current consumption ............................................................................................... 21
Enclosures
1 Circuit diagram
2 Layout
3 Wiring diagram(s)
4 Setting, adjustment instructions or service-test specification

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BANDELIN Compact Ultrasonic Cleaning Units for aqueous cleaning liquids are efficient and failsafe.
The performance of the units depends on a number of factors, e.g.
•the cleaning liquid used
•the filling-level in the oscillating tub or in the inserted beaker
•the quantity of goods to be cleaned
•the temperature of the cleaning or contact liquid.
Ultrasound will heat up the cleaning or contact liquid in the oscillating tub or in the inserted beaker
even without additional heating. After a 30 minutes exposure to ultrasonic waves, the temperature of
the cleaning or contact liquid increases from an initial 22 °C to approximately 35 to 45 °C without
covering the oscillating tub or the inserted beaker. During constant use, temperatures of more than
80 °C can be reached. If the oscillating tub or the inserted beaker has been covered, the
temperature of the cleaning or contact liquid will be increased to about 70 or 80 °C after 60 minutes
of constant use.
When switching on the heating in SONOREX units, the tolerances given by the thermostat-
switching hysteresis must be taken into consideration. Especially in the case of low heating
temperatures deviations of up to 10 °C are possible.
If disturbances should occur after a longer period, the following hints support the user to repair the unit.
1 Overview of possible faults, causes and remedies
Faults Possible causes Tests and Remedies
Unit cannot be switched on
→green pilot light is not
illuminated
→generator fuse blows
again after exchange
No power
- Plug loose?
- Defective mains fuse?
- Defective mains cable?
- Defective timer?
- Short-circuit on generator
PCB?
- Defective generator fuse?
- Defective transistors?
Liquid or foreign particles on
PCB?
- Check plug
- Change main fuse.
- Check cable for conductivity, if neces-
sary exchange it.
- Check plug connections 1-3 and 4-6 for
conductivity on wound-up timer, repeat
measurement on constant setting (∞)
on plug connections 1-2 and 4-6.
Change timer item 4.6
- Change fuse, measure resistance on
PCB between phase and phase and
bet-ween phase and protective earth
con-ductor.
- Check generator fuse for conductivity
and if necessary exchange.
- Check transistors for conductivity and
exchange if necessary, see item 4.1.
- Carefully clean PCB with compressed
air or return unit for repair to the
supplier.
Unit with heater - heater
does not work
- Defective heater fuse?
- Defective heater?
- Defective thermostat of
dry-run protector?
- Defective regulating
thermostat?
- Check for conductivity and if necessary
exchange.
- Check heater and exchange defective
heating elements, item 4. 4.
- Exchange, item 4. 4. 4
- Check and if necessary exchange,
items 4. 4. 5, 4. 4. 6.

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Faults Possible causes Tests and Remedies
Unsatisfactory cleaning
results
- Unsuitable cleaning agent?
- Overloaded with items to be
cleaned?
- Fill-height of cleaning liquid
in oscillating tub or inserted
beaker too low?
- Possible dirt layers on floor
of oscillating tub or inserted
beaker resp. many particles
in the cleaning liquid?
- Defective oscillating system?
- Use TICKOPUR, TICKOMED,
STAMMOPUR, STAMMOSEPT or ask
for advice.
- Reduce amount to be cleaned.
- Make sure it is 2/3rds full, goods to be
cleaned must be completely covered
with cleaning liquid.
- Empty oscillating tub or inserted
beaker, remove dirt, renew cleaning
liquid (see also operating instructions
"Cleaning/caring of unit”).
- If necessary replace oscillating
system, see item 4. 5 or return unit for
repair to the supplier.
Surface of oscillating tub
matt or erosion marks on
the surface
- Use of aggressive
cleaning liquids (e.g. acids,
cleaning liquids containing
chloride ions),
- removal of agressive dirt
(e.g. salt residues) or
abrasive dirt (e.g. polishing
paste)?
- Cavitation erosion? After
long operation periods, the
cavitation attacks the stain-
less steel surface of the
oscillation tub.
- Pitting corrosion?
Is caused by rust particles
from the water system, but
also by metal particles
which have remained in the
oscillating tub or aggressive
cleaning liquids.
- If the tub becomes leaky, it must be
exchanged. ⇒Return unit for repair
to the supplier.

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2 Repair advices
Repairs must only be carried out by authorised personnel.
Replace defective parts with SONOREX original parts only.
It is recommended to limit the repair of the units to the exchange of fuses, transistors, generator
PCB with base plate, the heater, transducers (without new bonding), as well as the timer. The parts
mentioned are supplied as replacement parts.
Information about electric components, connectors, cables, fuses can be found in the unit specific
enclosures.
In the case of measurements and adjustments, the oscillating systems must be connected with the
generator. Use an extension cable for this and take care that the blue lead is well insulated
→high frequency voltage of ≈500 Vrms.
In some devices the red transducer line is connected to protective ground and/or with the tank.
3 Disassembly of unit
ATTENTION! Before opening the unit, pull the mains plug!
- Place the unit upside down.
- Carefully remove the base plate:
•for units RK 31/H, RK 52/H/CH, RK 100/H/SH, TK 100/H, RK 102H/CH, RK 103H/CH,
RK 156/BH, RK 158S, RK 170/H, RK 255H/CH, RK 510/H, RK 512H/CH, RK 513, RK 514/H/BH,
RK 515 CH, RK 517H, RK 1028/H/BH/C/CH, RK 1029/H, RK 1040, RK 1050/BH/CH remove
screws from the base plate along the rim of the housing only.
•RK 106 unscrew 3 screws. Either the screws in the feet or the screws from the base plate
along the rim of the housing.
Note: Do not loosen the tank from the housing.
In case of defective tank or loosen adhering (of the oscillating systems) return unit for
repair to the supplier.
- Electrical plug connections between the base plate with generator PCB and case with oscillating
tub must be separated if necessary in accordance with the wiring diagram in appendix 3.
•Remove the connectors from the timer (2 yellow and 1 brown + 1 blue wire in a silicon hose)
•Remove both plugs for the heating (red wires), if necessary desolder power supply wire.
•Remove both plugs for the HF wires to the oscillating elements (one blue and one red wire in
a silicon hose).
- Exchange of fuses: - The fuses are located on the generator.
- Check fuses and replace only defective ones.
- Spare fuses are on the base plate.

4 Repairs
4.1 Check of transistors
Check the transistors before exchanging, in order to save unnecessary costs.
The transistors can be checked in the inserted condition:
B C E
Check of the bipolar transistors (generators without ICs):
1) Diode behaviour of the paths B-E, B-C and E-C: in forward direction
approx. 300 … 500 mV voltage drop. In reverse direction no check is possible
due to the circuitry outside the transistor.
In some generators the inverse diode (E-C) is situated at the board and can
not be checked at the desoldered transistor.
Check of IGBTs (generators with ICs):
G C E
1) Diode behaviour of the path E-C: in forward direction
approx. 300 … 500 mV voltage drop.
2) The path G-E is “high impedance”, but to parallel circuitry it
takes some seconds to obtain a voltage > 1 V.
The voltage drop indicated depends on the instrument and is
different for the two IGBTs due to different circuitry.
4. 2 Exchange of transistors
4. 2. 1 Transistors in insulated case (Isowatt 218)
The transistors (for example BUV 48 AFI/IV48A (Isowatt 218)) are mounted on the base plate.
They can be exchanged as follows:
- Loosen the self locking nut M3 on the transistor.
- Cut off the transistor connections just below the transistor using side cutting pliers.
- The transistor is attached to the base plate by means of heat conducting paste, remove defective
transistor using a knife blade or similar.
- Desolder the transistor connections.
- Tighten the new transistor with self locking nut.
- Solder the connections to PCB.
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self locking nut and disc
base plate
heat conducting paste
disc 3,2
hexagon socket head cap screw
DIN 912 M 3 × 12
transistor Isowatt 218 BUV 48 AFI/I V 48 A

4. 2. 2 Transistors with plastic case (TO-220) and synthetic material press-on plate
Exchange the transistor as follows:
- Loosen the self locking nuts and the countersunk screws M3 and remove the transistor holder.
- Cut off the transistor connections just below the transistor using side cutting pliers.
- The transistors are attached to the mica disc with heat conducting paste. Remove the transistor
carefully using a knife blade or similar.
- Desolder the transistor connections.
- Assemble the transistor with the transistor holder, then solder it back on.
- Re-adjustment is not necessary, if possible the power input should be measured after the transistor
has been exchanged; if it deviates from the nominal value by more than 20 % (see type plate), the
power output must be adjusted again.
disc
transistor holder TK-52
transistor TO 220-2
SC 2502
(diode MUR 180)
nut
mica disc TK-50, heat
conducting paste on
both sides
countersack screw
PCB
Base plate
4. 2. 3 Transistors in metal case (TO-3)
Use matched pairs only.
Exchange the transistor as follows (fig. 3):
- Unsolder all connecting leads from one transistor.
- Loosen self locking nut and hexagon socket screw M3 from the transistor.
- Transistors adhere due to the heat conducting paste on mica disc. Remove the transistor carefully
using a knife blade or similar.
- The transistors must be assembled very carefully with heat conducting paste, mica disc and insu-
lating bushes so that the transistors are cooled well and no flashovers occur.
- Solder the connecting leads back on using the second transistor which still has the original wiring
attached, as a pattern.
- Exchange the second transistor.
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insulating disc, epoxy,
diam.
15/3.2; 1 thick
disc ∅12/3.2; Din 125
mica disc 0.13 - 0.17 thick, heat
conducting paste on both sides
hollow filed with heat conducting paste
self locking nut
hexagon socket head cap
screw DIN 912; M 3 × 12
transistor TO-3
BUY 69/ BUX 48/
transistor connections
BUX 98 (A)
spring lock washer DIN 127, B3
insulating bush
cooling plate

4.2.4 Transistor in plastic case and metal clip(s)
shunt for current
measurement
Before changing the transistors verify the shunt of the
current measurement.
The value (imprinted) should be between 0,5 and 10 Ω.
If this resistor has blown, further damages are probable
and the equipment must be returned to the supplier for
repair.
The exchange is to be made as follows:
- Unscrew the head screws M3 and remove the fixing clip(s). (Caution: when removing the screw the
cooling plate is unfixed as well. It only sticks by the thermal compound.)
- Cut the transistor legs underneath the transistor with a side cutter.
- Remove the transistor with the insulating tube.
- Unsolder transistor connections.
Attention: No strength must be applied when pulling out the transistor legs. Prefere desoldering
using a vacuum-pump instead of pulling the pin. If there are too much remnants of
soldering tin or flux, than they have to be removed separately. If necessary disassemble
the generator (not unplugging the wired connections). Remove the four screws from the
board. Turn the board upside-down lifting the side with the transformer, HF-terminals
and transistors over the opposite side (containing the mains fuse and the current shunt).
Care for the cooling plate, which must not be moved.
Note for the assembly: The 4 short screws are intended to fixate the plate, the longer
screw is for the fixing clip.
Tighten the screws by hand!
- Examine, whether the cooling plate was shifted, possibly adjust (it must not overlap with the board)
and assemble the transistors with the fixing clip. Therefore, plug in transistors into holes. The
transistor legs should look trough the hole by about 1 mm. Do not cut the legs, but adjust them.
Bend the transistors until they fit on the cooling plate (slight spring back is allowed). Next step is
soldering the transistor connections.
- Slide the standard insulating tube over the new transistor until it stuck on the board, but not between
board and transistor connections.
Attention: Handle cautiously – already small rifts or holes at the bottom side of the tube will cause
malfunction.
- No recalibration of power or frequency is required.
insulating tube
fixing clip
transistor in
insulating tube
generator bard
cooling plate
base plate (housing)
cross recessed pan head screw M3
generator board
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4. 3 Exchanging the generator PCB including the base plate
Return ultrasonic cleaners RK 1028 C and RK 1050 /CH for repair to the supplier. The following repair
instructions are not applicable for this type of units.
4. 3. 1 With original generator of older type and supply of a replacement generator
without ICs
The generator PCB with base plate is preadjusted. The complete unit can be exchanged directly.
However, deviations of the actual power input from the nominal power input stated on the type label
cannot be excluded. If there is a greater deviation, the generator has to be readjusted.
Adjustment of generator
ATTENTION! You are working with very high voltages!
You will need:
- watt meter, corresponding to the power consumption
- variable isolating transformer up to 250 V, corresponding to the power consumption
- circuit diagram, see appendix 1
- wiring diagram, see appendix 3
- adjustment instructions, appendix 4
- oscilloscope up to 20 MHz, modular oscilloscope probe 1:100, current probe
The generator is usually adjusted as follows:
- Disassemble the base plate with the generator PCB completely and place it next to the tub.
- Connect the transducers under the dry tub with the generator by means of a voltage-stable two-pole
adapter cable.
- Replace the timer by wiring bridges.
- Turn the variable isolating transformer to zero! Connect the generator to the regulating transformer
using a two-pole mains cable.
- Fill the tub 2/3 with lukewarm water. Add a splash of detergent.
- Adjust the regulating transformer slowly to approx. 150 V (115 V units: 75 V). At this value the
generator should start to oscillate. If not, switch the regulating transformer off and on again at 150 V
(115 V units: 75 V).
- Watch the reading on the watt meter. Slowly turn the regulating transformer to 230 V (115 V units:
115 V).
If the power input deviates by more than +/- 20 % from the nominal value it can be set by carefully
adjusting the core in the swinging choke, see layout (appendix 2). Once the correct value has been
set, the adjusted core must be fixed with silicon rubber.
- Disconnect the unit from the transformer and re-assemble.
4.3.2 With original generator of older type (G) and supply of a replacement
generator (FH1-2) with ICs
New generators FH1-2 are recognized clearly by the transistors with fixing clip and the ICs on the board,
see also point 4.2.4.
The supplied generator with base plate can compensate the equipments tolerances by its regulation.
The complete unit can be exchanged directly without a new adjustment.
Replacement parts:
1 FH1-2 generator with base plate
1 mounting kit, consisting of:
- 2 pieces cable with flat pin bushing
(to be used with soldered mains entry)
- 2 pieces flat pin splitter (V 002)
(to be used with units with heating)
If the new generator has to be assembled with an older equipment, connect it as follows:
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- In case of change of wiring at timer
lamp
to the generator
1-pole timer (N)
connect with: X3 X1 X2
2-pole timer (L)
lamp
to the generator
remove this
line
connect with: X3 X1 X2
- Wiring of FH1-2 for older equipment with heating
flat pin splitter
X 1X 2X 8X 9X 3X 5X 4
Generatorplatine FH1-2
HF-line
to the oscillating
systems
heating to the timer
mains plug or mains cable
PE at the base
plate
PE
- Wiring of FH1-2 for older equipment without heating
X 1X 2X 8X 9X 3X 5X 4
Generatorplatine FH1-2
HF-line
to the oscillating
systems to the timer
mains plug or mains cable
PE at the base
plate
PE
Attention: Take care of effective protective earth (PE) connections!
The generator board does not have a PE connection (gn/ye). It must be guaranteed that the following
components are connected by PE braids:
tank, housing and generator base plate.
If there is a remaining PE-wire, plug it on a free PE plug (e.g. free plug on the housing bottom) or remove
it by a side cutter.
Potentially existing mains plug with EMC filters have to be replaced by normal mains plugs.
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