Drazice OKCE 100 NTR Specification sheet

OPERATING AND
INSTALLATION MANUAL
STATIONARY STORAGE TANKS
OKCE 100 NTR/2,2 kW
OKCE 125 NTR/2,2 kW
Družstevní závody Dražice - strojírna s.r.o.
Dražice 69, 294 71 Benátky nad Jizerou
tel.: +420 / 326 370 990
fax: +420 / 326 370 980
e-mail: [email protected]

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CONTENT
1 TECHNICAL SPECIFICATION OF PRODUCT ................................................................................................. 4
1.1 FUNCTION DESCRIPTION ................................................................................................................... 4
1.2 PRODUCT DESCRIPTION .................................................................................................................... 4
1.3 DESIGN AND GENERAL DIMENSIONS ................................................................................................ 5
1.4 TECHNICAL PARAMETRES.................................................................................................................. 6
2 OPERATION AND FITTING INSTRUCTIONS................................................................................................. 7
2.1 OPERATING CONDITIONS .................................................................................................................. 7
2.2 ELECTRIC INSTALLATION.................................................................................................................... 7
2.2.1 WIRING FOR: OKCE 100 S/2,2 kW, OKCE 125 S/2,2 kW ............................................................ 7
2.3 PLUMBING FIXTURE........................................................................................................................... 8
2.4 PRESSURE LOSSES.............................................................................................................................. 9
2.5 CONNECTION OF STORAGE TANK TO HOT WATER HEATING SYSTEM............................................ 10
2.6 EXAMPLES OF STORAGE TANKS CONNECTION................................................................................ 10
2.7 PUTTING INTO OPERATION ............................................................................................................. 13
2.8 STORAGE TANK CLEANING AND ANODE ROD EXCHANGE .............................................................. 13
2.9 SPARE PARTS.................................................................................................................................... 14
3 OPERATION OF THERMOSTAT................................................................................................................. 14
3.1 SERVICING........................................................................................................................................ 14
3.1.1 OPERATING DEVICES OF THE STORAGE TANK......................................................................... 14
3.1.2 TEMPERATURE SETTING .......................................................................................................... 15
3.2 MOST FREQUENT FUNCTION FAILURES AND THEIR CAUSES .......................................................... 15
4 IMPORTANT NOTICES .............................................................................................................................. 16
4.1 INSTALLATION REGULATIONS.......................................................................................................... 16
4.2 DISPOSAL OF PACKAGING MATERIAL AND FUNCTIONLESS PRODUCT ........................................... 17

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Meaning of pictograms used in Manual
Important information for storage tank users.
Recommendations of manufacturer, observance of which will ensure trouble-free
operation and long service life of the product.
CAUTION!
Important nice to be observed.
READ CAREFULLY THE BELOW INSTRUCTIONS PRIOR TO THE INSTALLATION OF
THE STORAGE TANK!
Dear customer,
The Works Cooperative of Dražice - Machine Plant, Ltd., would like
to thank you for your decision to use a product of our brand. With
this guide, we will introduce you to the use, construction,
maintenance and other information on electrical storage tanks.
The manufacturer reserves the right for engineering modification of the product. The product is designed for
permanent contact with drinkable water.
It is recommended to use the product in indoor environment with air temperatures from +2°C to 45°C and a
relative humidity up to 80%.
Product’s reliability and safety is proven by tests implemented by the Engineering Test Institute in Brno.

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1TECHNICAL SPECIFICATION OF PRODUCT
1.1 FUNCTION DESCRIPTION
Thanks to their construction and number of variants, the OKCE 100, 125 NTR series storage tanks enable
economic preparation of hot service water (HSW) by means of various power sources. Their nominal
performance provides sufficient amount of hot water for flat units, premises, restaurants, and similar
establishments. For HSW reheat, electricity, various types of central heating boilers, recoverable energy
sources (heat pumps, solar collectors) and combination of those can be chosen.
Service water heating via thermal energy through heat exchanger
Closing valves of the heat exchanger must be opened which ensures heating water flow from the hot water
heating system. Together with a closing valve, it is recommended to install an air outlet valve at the inlet to
the heat exchanger in order to bleed the heat exchanger as needed, in particular before the beginning of
the heating season. The time of heating using the heat exchanger depends on the temperature and flow of
water in the hot water heating system.
1.2 PRODUCT DESCRIPTION
The storage tank vessel is welded from a steel sheet; the exchangers from a steel tube and, as a unit, it is
entirely coated with hot water resistant enamel. A flange is welded onto the upper bottom of the
receptacle with a flange lid screwed to it. A sealing ring is inserted between the flange lid and the flange.
Thermowells for placing a heating element and sensors of regulation thermostat and safety fuse are
located in the flange lid. Electric wiring is placed underneath the plastic removable cover. The temperature
of water can be set using the thermostat.
For additional corrosion protection a magnesium anode is mounted in the upper part of the storage tank to
adjust the electric potential inside the tank, reducing the risk of corrosion. The storage tanks have outlets of
hot and cold water and a circulation opening welded to them. The tank is insulated with polyurethane foam
of 40 - 65 mm thickness. The storage tank shell consists of a steel, powder-paint coated, sheet; the
connecting parts are metal coated. The entire storage tank stands on three rectification screws with a
possibility of levelling floor unevenness within the range of 10 mm. The storage tank is to be placed on the
ground. The tank is tested with pressure of 0.9 MPa, heat exchangers with 1.5 MPa.
The NTR version has a heat exchanger located in the bottom part of the storage tank and one heating water
source is used for heating.

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A885 1050
B881 1049
C127 128
D524 524
E182 182
F622 752
L522 622
Type
OKCE 100 NTR/2,2 kW
OKCE 125 NTR/2,2 kW
1.3 DESIGN AND GENERAL DIMENSIONS
OKCE 100 NTR/2,2 kW, OKCE 125 NTR/2,2 kW
Figure 1
①
1" vnější
②
3/4" vnitřní
③
3/4" vnější
④
1/2" vnitřní
Hot utility water
outlet
Cold water inlet

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1.4 TECHNICAL PARAMETRES
TYPE
OKCE 100 NTR/2,2kW
OKCE 125 NTR/2,2 kW
CAPACITY [l]
96
115
WEIGHT[kg]
59
71
OPERATING PRESSURE IN THE TANK [MPa]
0,6
OPERATING OVERPRESSURE IN THE
EXCHANGER [MPa]
1
MAX RATING WATER TEMPERATURE [°C]
110
MAX TEMPERATURE OF HSW [°C]
80
LOWER EXCHANGER HEAT DELIVERY SURFACE [m2]
1
1,45
BOTTOM EXCHANGER OUTPUT AT RATING WATER
TEMPERATURE OF 80 °C AND FLOW 720 l/h [kW]
24
32
PERMANENT OUTPUT HSW [l/h]
610
990
TIME OF HEATING BY EXCHANGER FROM 10°C TO
60 °C [min]
14
14
TIME OF RATING WITH ELECTRICITY FROM 10°C TO
60 °C [h]
3
3,5
POWER INPUT [kW]
2,2
ELECTRIC CONNECTION OF CONTROL ELEMENTS
1 PE-N 230 V/50 Hz
IP PROTECTION
IP 44
STANDING LOSS [W]
42
54
Table 1

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2OPERATION AND FITTING INSTRUCTIONS
2.1 OPERATING CONDITIONS
The tank shall only be used in accordance with the conditions specified on the power plate
and in instructions for electric wiring. Besides legally acknowledged national regulations and
standards, also conditions for connection defined in local electric and water works have to
be adhered to, as well as the installation and operation manual.
The temperature at the place of storage tank installation must be higher than +2°C; and the
room must not freeze. The appliance has to be mounted at a convenient place; it means that
the appliance must be easily available for potential necessary maintenance, repair or
replacement, as the case may be.
If water is strongly calcareous we recommend that any of the common decalcifying devices
was installed with the appliance, or that the thermostat was set to the minimum operating
temperature of 60°C (setting to position “60“). For proper operation, drinkable water of
adequate quality shall be used. To avoid potential sediments we recommend that the device
was installed together with a water filter.
2.2 ELECTRIC INSTALLATION
2.2.1 WIRING FOR: OKCE 100 S/2,2 KW, OKCE 125 S/2,2 KW
The electric wiring scheme is attached to the storage tank on the side of the electric installation guard.
Connection, repairs, and wiring inspections may only be implemented by a company (person) authorised to
such activity.
The storage tank is connected to the 230 V/50 Hz electric network using a fixed moving conductor with a
switch that turns off all network poles and the circuit breaker (protector). The degree of protection of
electric parts of the storage tank is IP 44.
Wiring scheme:
Figure 2

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2.3 PLUMBING FIXTURE
Power water connects to pipes with 3/4“ thread in the bottom part of the storage tank. Blue
- cold water supply, red - hot water outlet. For potential disconnection of the storage tank,
the service water inlets and outlets must be provided with screw coupling Js 3/4“. The safety
valve is mounted on the cold water inlet identified with a blue ring.
Each hot service water pressure storage tank must have a safety valve with a membrane
spring. Nominal clearance of safety valves is defined by standard. Storage tanks are not
equipped with a safety valve. The safety valve must be easily accessible, as close to the
storage tank as possible. The inlet pipes must have at least the same clearance as the safety
valve. The safety valve is placed high enough to secure dripping water drain by gravity. We
recommend mounting the safety valve onto a branch pipe. This allows easier exchange
without having to drain the water from the storage tank. Safety valves with fixed pressure
settings from the manufacturer are used for the assembly. Starting pressure of a safety valve
must be identical to the maximum allowed storage tank pressure and at least 20 % higher
than the maximum pressure in the water main (Table 2). If the water main pressure exceeds
such value, a reduction valve must be added to the system. No stop valves can be put
between the storage tank and the safety valve. During the assembly, follow the guide
provided by the safety equipment manufacturer.
It is necessary to check the safety valve each time before putting it into operation. It is
checked by manual moving of the membrane from the seat, turning the make-and-break
device button always in the direction of the arrow. After being turned, the button must click
back into a notch. Proper function of the make-and-break device results in water draining
through the safety valve outlet pipe. In common operation, such a check needs to be
implemented at least once a month, and after each storage tank shutdown for more than 5
days. Water may be dripping off the drain pipe of the safety valve; the pipe must be open
into the air, pointed down; environment temperatures must not drop below zero. When
draining the storage tank, use the recommended drain valve. First, close the water supply
into the storage tank.
Please find necessary pressure values in the below Table 2. For proper safety valve operation, a backflow
valve must be mounted on the inlets pipes, preventing spontaneous storage tank draining and hot water
penetrating back into the water main. We recommend that the hot water distribution from the storage
tank was as short as possible to minimise heat losses. At least one demountable joint must be mounted
between the tank and every supply pipe.
Adequate piping and fittings with sufficiently dimensioned maximum temperature and pressure values
must be used.

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11,5 235
10
20
50
100
200
Výměník s teplosměnou
plochou 1 m2
Výměník s teplosměnou
plochou 1,45 m2
Průtok topné vody m3/h
Odpor topnévody
mbar
4
Type
1 2 3 4 5
Exchanger 1 m2 724 51 86 130
Exchanger 1.45 m2
932 68 115 174
Pressure loss mbar
tHV = 60 °C
Amount of heating water in m3/h
Storage tanks must be provided with a discharge
valve mounted on the cold service water inlet to the
storage tank for potential disassembly or repair.
When assembling the security equipment, follow
the standards.
SAFETY VALVE
STARTING
PRESSURE
[MPa]
ADMISSIBLE
OPERATING
STORAGE
TANK
PRESSURE
[MPa]
MAX
PRESSURE IN
THE COLD
WATER PIPE
[MPa]
0,6
0,6
up to 0,48
0,7
0,7
up to 0,56
1
1
up to 0,8
Table 2
2.4 PRESSURE LOSSES
Exchanger with heat
transfer surface 1.45 m2
Exchanger with heat
transfer surface 1 m2
Heating water flow m3/hour
Heating water resistance
mbar

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2.5 CONNECTION OF STORAGE TANK TO HOT WATER HEATING
SYSTEM
a) Water heating by electric energy
After the storage tank is connected to electric network, the heating element starts heating water. The
element is turned on and off by a thermostat. After reaching the temperature set, the thermostat switches
off the electric circuit and thus discontinues water heating. The control light signals if the element is in
operation (light is on) or if it is off (the light goes out). In case of longer operation without using the heated
volume, the thermostat has to be set to position 5°C to 8°C (set the “snowflake” symbol on the thermostat
selector) to avoid its freezing, or electricity supply to the storage tank has to be switched off.
In combined versions, the stop valve on the inlet to the exchanger has to be closed, which prevents heating
water in the hot water heating system.
b) Service water heating via thermal energy through heat exchanger
Closing valves of the heat exchanger must be opened which ensures heating water flow from the hot water
heating system. Together with a closing valve, it is recommended to install an air outlet valve at the inlet to
the heat exchanger in order to bleed the heat exchanger as needed, in particular before the beginning of
the heating season (
Figure 4). . The time of heating using the heat exchanger depends on the temperature and flow of water in
the hot water heating system. A storage tank is made in universal design - depending on the need of
connecting the closing valves to the heating element either from the right, or from the left.
It is recommended to install stop valves on the heating water inlet and outlet (for possible
dismantling of the storage tank). The valves have to be as close to the storage tank as
possible to avoid higher thermal losses.
2.6 EXAMPLES OF STORAGE TANKS CONNECTION
Connecting a storage tank to a heating circuit
The storage tank is placed on the ground, next to the heating source, or in its vicinity. The heating circuit is
connected to marked inputs and outputs of the storage tank exchanger; the deaeration valve is mounted in
the highest place. It is necessary to install a filter into the circuit in order to protect the pumps, the three-
way valve, and backflow flaps, and the exchanger from sedimentation. It is recommended to flush the
heating circuit before the assembly. All wiring connections must be properly insulated from heat.
If the system works with priority heating of HSW using a three-way valve, always follow the installation
instructions of the three-way valve’s manufacturer.
Connecting a storage tank to a hot water distribution
Cold water shall be connected to an inlet marked with a blue ring and writing “HSW INLET”. Hot water shall
be connected to an outlet marked with a red ring or writing “HSW OUTLET”. If the hot service water (HSW)

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distribution is equipped with circulation circuit, it shall be connected to the outlet marked with
“CIRCULATION”. For potential drain of storage tank, the HSW inlet has to be provided with a “T” fixture
with a drain valve. Each individually lockable storage tank must be at the cold water inlet provided with a
stop gate, test cock, safety valve with a reverse flap and a pressure gauge.
An example of a group storage tank connection for steady hot water consumption from all tanks using
Tichelmann´s method
HW –hot water HSW –hot service water
CW –cold water 1 –return valve
C –Circulation 2 - pump
Figure 3

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Figure 4

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2.7 PUTTING INTO OPERATION
After connecting a storage tank to the water main, the hot water heating system, the electric network, and
after testing its safety valve (based on the valve manual attached), the storage tank may be put into
operation.
PROCEDURE:
a) Check water and electric installation as well as the installation to a hot water heating system. Check
proper placement of operating and safety thermostat sensors. The sensors must be inserted all the
way in; first the thermostat and then the safety fuse.
b) Open the hot water valve on the combination faucet.
c) Open the cold water inlet valve to the storage tank.
d) When the water starts flowing through the hot water valve, the filling of the storage tank is finished
and the valve needs to be closed.
e) Should a leak (of the flange lid) occur, we recommend tightening the screws of the flange lid.
f) Fasten the electric installation cover.
g) When heating service water heating by electric energy, turn on the electricity (the heating water
inlet to the heating insert must be closed).
h) When heating the water with thermal energy from a hot water heating system, turn off the
electricity and open the valves at the inlet and outlet of heating water or bleed the exchanger.
i) When commencing operation, flush the storage tank until the cloudiness in the water is gone.
j) Make sure to fill in properly the warranty certificate.
2.8 STORAGE TANK CLEANING AND ANODE ROD EXCHANGE
Repetitive water heating causes limestone sediment on both the enamelled tank walls and chiefly the
flange lid. The sedimentation depends on the hardness of water heated, its temperature, and amount of
hot water consumed.
We recommend checking and cleaning the tank from scale and eventual replacement of
the anode rod after two years of operation.
The anode life is theoretically calculated for two years of operation; however, it changes with water
hardness and chemical composition in the place of use. Based on such an inspection, the next term of
anode rod exchange may be determined. Have the company in charge of service affairs clean and exchange
the anode. When discharging water from the storage tank, the mixing valve of the hot water tap must be
open in order to avoid creating underpressure that would prevent water discharge.

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To prevent formation of bacteria (e.g. Legionella pneumophila) within stack heating it is
recommended, if absolutely necessary, to increase the temperature of HSW periodically
for a transitional period of time to at least 70°C. It is also possible to make use of another
way of HSW disinfecting.
2.9 SPARE PARTS
- Flange lid - flange lid seal - insulation flange lid
- Thermostat and thermal fuse - Magnesium anode - control button for the thermostat
- Control lights with wires - capillary thermometer - set of M12 (or M10) bolts
- Heating element
When ordering spare parts, give part name, type, and type number from the storage tank label.
3OPERATION OF THERMOSTAT
3.1 SERVICING
3.1.1 OPERATING DEVICES OF THE STORAGE TANK
Service devices of storage tanks of 100 and 125 l capacity are located under the transparent guard of the
control panel (Figure 5Figure 5).
Thermostat knob Electric circuit power indicator lamp Tipping transparent guard
Figure 5

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3.1.2 TEMPERATURE SETTING
Water temperature se is set by turning the thermostat knob. The desired symbol is adjusted against the
fixed point on the control panel (Figure 6).
Figure 6
Adjusting the thermostat selector at the left backstop does not mean permanent shutoff of
the heating element. When the storage tank is in use without blocking the daily rate, we do
not recommend the temperature to be set above 65°C. The maximum value to select is „55“.
3.2 MOST FREQUENT FUNCTION FAILURES AND THEIR CAUSES
DEFECT
CONTROL LIGHT
FAILURE
Water in the tank is cold
Is on
Heating element failure
Water in the tank is not
warm enough
is on
Failure of one of the heating
coils in the element
Water in the tank is cold
is not on
Thermostat failure
The safety fuse turned off
electricity supply
Power supply outside the
storage tank discontinued
Water in the tank does
not correspond with
temperature set
is on
Thermostat failure
Table 3
Lower temperature range
(about 5°C)
Fixed point on the control
panel
„Anti-freezing“
temperature (about 8°C)
pevný bod na ovládacím
panelu
teplota „proti zamrznutí“
(kolem 8°C)
Upper temperature range
(about 74°C)
„Ideal“ temperature (about
55°C)
„optimální“ teplota
(kolem 60°C)

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Do not try to repair the failure yourselves. Seek either expert or service help. It does not take
much for an expert to remove the defect. When making a repair appointment, report the
type and serial number you find on the performance plate of your storage tank.
4IMPORTANT NOTICES
4.1 INSTALLATION REGULATIONS
Without a confirmation of performed electrical installation issued by an authorised
company, the warranty certificate shall be void.
The Mg anode has to be checked regularly and exchanged, if needed.
No stop valves can be put between the storage tank and the safety valve.
If the overpressure in the water main exceeds 0.48 MPa, a pressure control valve must be
mounted before the safety valve.
All hot water outputs must have a combination faucet.
Before filling the storage tank with water for the first time, it is recommended to fasten the
flange connection nuts of the tank.
It is not allowed to handle the thermostat, aside from temperature resetting with a control
button.
All electric installation handling, adjustment and replacement of the regulation elements
shall only be performed by an authorised service company.
The thermal fuse must not be turned off! In case of thermostat defect, the thermal fuse
interrupts electric power input to the heating element if the water temperature in the
storage tank exceeds 95°C.
As an exception, the thermal fuse may also switch off due to water overheating caused by
overheating the hot water heating system boiler.
We recommend you operate the storage tank with one type of energy.
Both the electric and water installation must follow and meet the requirements and
regulations relevant in the country of use!

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4.2 DISPOSAL OF PACKAGING MATERIAL AND FUNCTIONLESS
PRODUCT
A service fee for providing return and recovery of packaging material has
been paid for the packaging in which the storage tank was delivered. The
service fee was paid pursuant to Act No. 477/2001 Coll., as amended, at EKO-
KOM a.s. The client number of the company is F06020274. Take the water
boiler packages to a waste disposal place determined by the town. When the
operation terminates, disassemble and transport the discarded and
unserviceable storage tank to a waste recycling centre (collecting yard), or
contact the manufacturer
09-2015