Drazice OKCE 200 NTR Specification sheet

OPERATING and
INSTALLATION MANUAL
STATIONARY ELECTRICAL WATER TANKS
OKCE 160 NTR / 2,2 kW OKC 160 NTR /BP
OKCE 200 NTR / 2,2 kW OKC 200 NTR / BP
OKCE 250 NTR / 2,2 kW OKC 250 NTR /BP
OKCE 300 NTR / 2,2 kW OKC 300 NTR / BP
OKCE 300 NTR / 3-6 kW OKC 200 NTRR / BP
OKCE 200 NTRR / 2,2 kW OKC 250 NTRR / BP
OKCE 250 NTRR / 2,2 kW OKC 300 NTRR / BP
OKCE 300 NTRR / 2,2 kW
OKCE 300 NTRR / 3-6 kW
Družstevní závody Dražice - strojírna s.r.o.
Dražice 69, 294 71 Benátky nad Jizerou
Phone.: [phone]
Fax: +420 / 326 370 980
e-mail: [email protected]

- 2 -
CONTENTS
1 PRODUCT TECHNICAL SPECIFICATION....................................................................................................... 4
1.1 FUNCTION DESCRIPTION ................................................................................................................... 4
1.2 PRODUCT DESCRIPTION .................................................................................................................... 4
1.3 DESIGN AND BASIC DIMENSIONS OF TANK....................................................................................... 5
1.4 TECHNICAL PARAMETERS.................................................................................................................. 9
2 OPERATION AND FITTING INSTRUCTIONS............................................................................................... 13
2.1 OPERATING CONDITIONS ................................................................................................................ 13
2.2 ELECTRICAL INSTALLATION.............................................................................................................. 13
2.2.1 ELECTRIC HEATING UNIT'S TECHNICAL PARAMETERS............................................................. 14
2.2.2 HEATING UNIT - FLANGES........................................................................................................ 15
2.2.3 WIRING SCHEME...................................................................................................................... 15
2.3 PLUMBING FIXTURE......................................................................................................................... 16
2.4 PRESSURE LOSSES............................................................................................................................ 18
2.5 EXAMPLES OF CONNECTING TANKS................................................................................................ 18
2.6 FIRST COMMISSIONING................................................................................................................... 22
2.7 HSW (HOT SANITARY WATER) TEMPERATURE CONTROL ............................................................... 22
2.7.1 hsw temperature control for 300 litre tanks........................................................................... 22
2.7.2 hsw temperature control for 160-250 litre tanks.................................................................... 23
2.8 CLEANING OF TANK AND EXCHANGE OF ANODE ROD.................................................................... 24
2.9 SPARE PARTS.................................................................................................................................... 25
3 IMPORTANT NOTICES .............................................................................................................................. 25
3.1 INSTALLATION REGULATIONS.......................................................................................................... 25
3.2 DISPPOSAL OF PCKAGING MATERIAL AND NON-FUNCTIONING PRODUCT.................................... 26

- 3 -
Meaning of pictograms used in the Manual
Important information for tank users.
Abiding by the recommendations of the manufacturer serves to ensure trouble-free
operation and the long service life of the product.
Caution!
Important notice to be observed.
PRIOR TO THE INSTALLATION OF THE TANK, READ CAREFULLY THIS MANUAL!
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. The
present instructions will introduce you to the use, construction,
maintenance and other information regarding electrical water
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.

- 4 -
1PRODUCT TECHNICAL SPECIFICATION
1.1 FUNCTION DESCRIPTION
The construction of OKC 160 - 300 series tanks and their variety allow economic preparation of hot sanitary
water (HSW) using different energy sources. Their nominal performance provides sufficient amount of hot
sanitary water for flat units, premises, restaurants, and similar establishments. HSW can be heated by
electric energy, different types of central heating boilers, recoverable energy sources (heat pumps, solar
collectors) and combinations of those.
Sanitary 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 it takes to heat up using the heat exchanger depends on the temperature and
flow of water in the hot water heating system.
1.2 PRODUCT DESCRIPTION
The tank receptacle is welded of steel plate, heat exchangers of steel tube and, as a unit, enamelled to
resist hot water. There is an additional protection against corrosion in the upper part of the tank and, in
selected models, also in the side flange (see a list on p. 25) in form of mounted magnesium that adjusts
electrical potential of the receptacle's inside, thus reducing the effects of it getting corroded. Tanks have
hot and cold water outlets welded on, and a circulation opening. The receptacle is insulated with
polyurethane foam of 40 - 65 mm thickness. The shell of the tank is steel plate coated with powder dye;
connecting pieces are metal coated. The entire tank stands on three adjusting screws with a possibility of
aligning floor unevenness in 10 mm range. Under the plastic cover on the side of the tank, there is a
cleaning and revision opening ended with a flange; a heating unit of different power can be mounted in the
opening. NTR and NTRR series tanks from 200 litre capacity are equipped with a 6/4“ aperture for screwing
in an additional heater TJ. This variant is used if the tank is connected in a solar system, or in a system with
heat pump, in order to finish heating water to the desired temperature in the upper part of the tank. The
tank is placed on the ground, next to the heating water source, or in its vicinity. The tank is tested with
pressure of 0.9 MPa, heat exchangers with 1.5 MPa.
NTR version has one heat exchanger located in the lower part of the tank, and uses one source of heating
water for heating.
The NTRR version is equipped with two exchangers for an optional combination of two heating water
sources; both exchangers can be combined in a series. The NTR/BP and NTRR/BP series do not have a
heating element. The tank cannot be used for flow heating of hot water in the heat exchanger.

- 5 -
1.3 DESIGN AND BASIC DIMENSIONS OF TANK
OKCE 160 NTR/2,2 kW, OKCE 200 NTR/2,2 kW, OKCE 250 NTR/2,2 kW
OKC 160 NTR/BP, OKC 200 NTR/BP, OKC 250 NTR/BP
Figure 1
Type
OKCE 160 NTR/2,2 kW
OKCE 200 NTR/2,2 kW
OKCE 250 NTR/2,2 kW
OKC 160 NTR/BP
OKC 200 NTR/BP
OKC 250 NTR/BP
A
1052
1362
1542
B
969
1282
1462
C
652
952
1062
E
-
813
813
F
782
782
782
G
212
212
212
H
82
82
82
160 l tank is not provided with a G 6/4" aperture.

- 6 -
OKCE 200 NTRR/2,2 kW, OKCE 250 NTRR/2,2 kW, OKC 200 NTRR/BP, OKC 250 NTRR/2,2 BP
Figure 2
Type
OKCE 200 NTRR/2,2 kW
OKCE 250 NTRR/2,2 kW
OKC 200 NTRR/BP
OKC 250 NTRR/BP
A
1362
1542
B
1282
1465
C
862
1065
D
922
1002
E
712
895
F
1152
1335
G
212
215
H
82
85
I
652
655

- 7 -
OKCE 300 NTR/2,2 kW, OKCE 300 NTR/3-6 kW, OKC 300 NTR/BP
Figure 3

- 8 -
OKCE 300 NTRR/2,2 kW, OKCE 300 NTRR/3-6 kW, OKC 300 NTRR/BP
Figure 4

- 9 -
1.4 TECHNICAL PARAMETERS
MODEL
OKCE 160 NTR/2,2kW
OKC 160 NTR/BP
Capacity [l]
148
149
Weight without water [kg]
88
77
TANK OPERATING PRESSURE [MPa]
0.6
HEAT EXCHANGER OPERATING PRESSURE
[MPa]
1
MAX TEMPERATURE OF HEATING WATER
[°C]
110
MAX TEMPERATURE OF HOT WATER [°C]
80
Heating surface of bottom heat
exchanger [m2]
1.45
Heating surface of upper heat exchanger
[m2]
BOTTOM/UPPER HEAT EXCHANGER
POWER AT HEATING WATER
TEMPERATURE OF 80 ℃AND FLOW OF
720 l/h [kW]
32
PERMANENT BOTTOM/UPPER HEAT
EXCHANGER HOT WATER POWER [l/h]
990
TIME OF HEATING BY EXCHANGER FROM
10°C TO 60 °C [min]
17
TIME OF HEATING BY ELECTRICITY FROM
10°C TO 60 °C [h]
4.5
INPUT [kW]
2.2
-
ELECTRICAL CONNECTION OF CONTROL
ELEMENTS
1 PE-N 230 V/50 Hz
ELECTRICAL PROTECTION
IP 44
STATIC LOSS [w]
75
75
Table 1

- 10 -
MODEL
OKCE 200
NTR/2,2kW
OKC 200
NTR/BP
OKCE 200
NTRR/2,2 kW
OKC 200
NTRR/BP
Capacity [l]
208
200
Weight without water [kg]
95
92
106
103
TANK OPERATING PRESSURE
[MPa]
0.6
HEAT EXCHANGER OPERATING
PRESSURE [MPa]
1
MAX TEMPERATURE OF
HEATING WATER [°C]
110
MAX TEMPERATURE OF HOT
WATER [°C]
80
Heating surface of bottom heat
exchanger [m2]
1.45
1.08
Heating surface of upper heat
exchanger [m2]
-
1.08
BOTTOM/UPPER HEAT
EXCHANGER POWER AT
HEATING WATER
TEMPERATURE OF 80 ℃AND
FLOW OF 720 l/h [kW]
32
2 x 24
PERMANENT BOTTOM/UPPER
HEAT EXCHANGER HOT WATER1
POWER [l/h]
990
670/650
*1080
TIME OF HEATING BY
EXCHANGER FROM 10°C TO 60
°C [min]
22
28
16
TIME OF HEATING BY
ELECTRICITY FROM 10°C TO 60
°C [h]
5.5
INPUT2[kW]
2.2
-
2.2
-
ELECTRICAL CONNECTION OF
CONTROL ELEMENTS
1 PE-N 230 V/50 Hz
ELECTRICAL PROTECTION
IP 44
STATIC LOSSES [W]
96
82
96
82
1 Hot water 45 ℃
2 This information doesn't apply to NTR/BP types that don't contain a unit
* Heat exchangers connected in a series

- 11 -
Table 2
MODEL
OKCE 250
NTR/2,2kW
OKC 250
NTR/BP
OKCE 250
NTRR/2,2 kW
OKC 250
NTRR/BP
Capacity [l]
241
242
235
234
Weight without water [kg]
106
103
116
112
TANK OPERATING PRESSURE
[MPa]
0.6
HEAT EXCHANGER OPERATING
PRESSURE [MPa]
1
MAX TEMPERATURE OF
HEATING WATER [°C]
110
MAX TEMPERATURE OF HOT
WATER [°C]
80
Heating surface of bottom heat
exchanger [m2]
1.45
1.08
Heating surface of upper heat
exchanger [m2]
-
1.08
BOTTOM/UPPER HEAT
EXCHANGER POWER AT
HEATING WATER
TEMPERATURE OF 80 ℃AND
FLOW OF 720 l/h [kW]
32
2 x 24
PERMANENT BOTTOM/UPPER
HEAT EXCHANGER HOT WATER1
POWER [l/h]
990
670/650
*1080
TIME OF HEATING BY
EXCHANGER FROM 10°C TO 60
°C [min]
28
36
20
TIME OF HEATING BY
ELECTRICITY FROM 10°C TO 60
°C [h]
6.5
INPUT2[kW]
2.2
-
2.2
-
ELECTRICAL CONNECTION OF
CONTROL ELEMENTS
1 PE-N 230 V/50 Hz
ELECTRICAL PROTECTION
IP 44
STATIC LOSSES [W]
93
87
93
87
1 Hot water 45 ℃
2 This information doesn't apply to NTR/BP types that don't contain a unit
* Heat exchangers connected in a series
Table 3

- 12 -
MODEL
OKCE 300
NTR/2,2
kW
OKCE 300
NTR/3-6
kW
OKC 300
NTR/BP
OKCE 300
NTRR/2,2
kW
OKCE 300
NTRR/3-6
kW
OKC 300
NTRR/BP
Capacity [l]
294
292
296
288
285
285
Weight without water
[kg]
116
122
111
150
155
148
TANK OPERATING
PRESSURE [MPa]
0.6
HEAT EXCHANGER
OPERATING PRESSURE
[MPa]
1
MAX TEMPERATURE OF
HEATING WATER [°C]
110
MAX TEMPERATURE OF
HOT WATER [°C]
80
Heating surface of bottom
heat exchanger [m2]
1.08
Heating surface of upper
heat exchanger [m2]
1.08
BOTTOM/UPPER HEAT
EXCHANGER POWER AT
HEATING WATER
TEMPERATURE OF 80 ℃
AND FLOW OF 720 l/h
[kW]
35
27
PERMANENT
BOTTOM/UPPER HEAT
EXCHANGER HOT WATER1
POWER [l/h]
1100
760
TIME OF HEATING BY
EXCHANGER FROM 10°C
TO 60 °C [min]
24
16
TIME OF HEATING BY
ELECTRICITY FROM 10°C
TO 60 °C [h]
8.5/6.3
INPUT2[kW]
2.2
3-6
-
2.2
3-6
-
ELECTRICAL CONNECTION
OF CONTROL ELEMENTS
1 PE-N 230 V/50 Hz
ELECTRICAL PROTECTION
IP 44
STATIC LOSSES [W]
83
83
83
83
83
83
1 Hot water 45 ℃
2 This information doesn't apply to NTR/BP types that don't contain a unit
* Heat exchangers connected in a series
Table 4

- 13 -
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 the legally recognized national regulations
and standards, the conditions of connection prescribed by the local electrical and water
enterprises must be observed, as well as the fitting and user manual.
The temperature at the place of the 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
(water filter) was installed with the appliance, or that the thermostat was set to the
maximum operating temperature of 60oC (setting to position “60“) -. For proper operation,
drinkable water of adequate quality shall be used.
300 litre tanks are screwed to the bottom wooden pallet from the bottom by M12 screws.
When the tank is released from a pallet and before put in service, 3 screw legs have to be
mounted that are supplied as product accessories. Using three adjustable legs, vertical
position of the tank can be ensured within 10 mm range.
2.2 ELECTRICAL INSTALLATION
Wiring for: OKCE 160 NTR/2,2 kW, OKCE 200 NTR/2,2 kW, OKCE 200 NTRR/2,2 kW,
OKCE 250 NTR/2,2kW, OKCE 250 NTRR/2,2 kW, OKCE 300 NTR/2,2 kW, OKCE 300 NTRR/2,2 kW,
OKCE 300 NTR/3-6 kW, OKCE 300 NTRR/3-6 kW
Water tank is equipped with universal electrical heating unit with either fixed or optional power of heating
elements. A heating unit consists of a flange, to which one or three wells for ceramic heating elements and
one thermowell are welded (see fig.). The unit is fixed with 8 M10 screws of 160 mm spacing, or 12 M12
screws of 210 mm spacing. In plastic cover of electrical installation is service and safety thermostat, tank
operation pilot light and supply conductor bushing.
The sensors must be inserted all the way in; first the thermostat and then the safety fuse.
The performance of heating unit may be adjusted based on either required heating time or connecting
possibilities of electric energy distribution in the place of use.

- 14 -
2.2.1 ELECTRIC HEATING UNIT'S TECHNICAL PARAMETERS
Heating unit
2.2 kW
Universal heating unit 3-6 kW
POWER kW
2.2
3
3
4
6
VOLTAGE
1 PE-N AC
230 V 50 Hz
1 PE-N AC
230 V 50 Hz
2 PE-N AC
400 V 50 Hz
3 PE-N AC
400 V 50 Hz
3 PE-N AC
400 V 50 Hz
ELECTRICAL
PROTECTION
IP 44
NUMBER OF
HEATING
ELEMENTS
1
3
POWER OF
ONE ELEMENT
kW
2.2
2
Table 5
When the tank is connected to power supply, the heating element heats water. The element is turned on
and off by a thermostat. The thermostat may be set from 5°C to 74℃.
We recommend that the sanitary water temperature is set to the maximum of 60°C. This
temperature ensures optimum operation of the tank since thermal losses are reduced, and
electricity saved.
After reaching the set temperature, 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). If the tank is out of service for longer time, the thermostat can be set to the “snowflake” symbol in
winter period to avoid its freezing, or the power supply to the tank can be switched off.
Connection, repairs, and wiring inspections may only be implemented by company
(person) authorised to such activity. Expert connection must be confirmed on the warranty
certificate.
The tank is connected to the electrical network using a fixed mobile conductor with a switch that turns off
all network poles and the circuit breaker (protector).
The degree of protection of electric parts of the tank is IP 44.
Follow the instructions for protection against electric shock injury advised in a standard applicable in the
country of installation.

- 15 -
2.2.2 HEATING UNIT - FLANGES
OKCE 300 NTR/2,2 kW, OKCE 300 NTRR/2,2 kW
OKCE 160 NTR/2,2 kW, OKCE 200 NTR/2,2 kW,
OKCE 200 NTRR/2,2 kW, OKCE 250 NTR/2,2 kW,
OKCE 250 NTRR/2,2 kW
Fastening 8 x M10 Fastening 12 x M12
Figure 1 Figure 6
OKCE 300 NTR/3-6 kW, OKCE 300 NTRR/3-6 kW Electric installation guard and wiring
scheme
Operation indicator Control voltage 230 V/50 Hz
Thermostat of the tank
Fastening 12 x M12
Figure 2 Figure 8
2.2.3 WIRING SCHEME
Notice: Factory connection must not be changed!
Heating unit 2.2 kW
Figure 9
Flange 2,2 kW
Flange 2,2 kW
Flange 3-6 kW

- 16 -
Heating unit 3-6 kW
The 3-6 kW heating unit allows 4 universal types of connection based on either the required time of
heating, or possibilities of electric network in the place of use. To achieve the chosen performance of the
heating unit, connect the inlet conductor to the terminal board L1-L2-L3-N and interconnect the terminals
on the terminal board 1 –10 according to the below schemes:
R = 1 kW 3 kW 1 PE - N AC 230 V / 50 Hz
3 kW 2 PE - N AC 400 V / 50 Hz
4 kW 3 PE - N AC 400 V / 50 Hz
6 kW 3 PE - N AC 400 V / 50 Hz
2.3 PLUMBING FIXTURE
Power water connects to pipes with 3/4“ thread. Blue - cold water supply, red –hot water
outlet. For potential disconnection of the tank, utility water inlets and outlets must be
provided with Js 3/4“ screw coupling. The safety valve is mounted on the cold water inlet
identified with a blue ring.
Every hot utility water pressure tank shall be equipped with membrane spring loaded with
safety valve. Nominal clearance of safety valves is defined by standard. Safety valve shall be
easily accessible, fitted as close as possible to the tank. The inlet pipes must have at least the
same clearance as the safety valve. Safety valve is placed high enough to secure dripping
water drain by gravity. We recommend that safety valve is mounted on a branch. Easier
exchange without the necessity of draining water from the tank.
Safety valves with fixed pressure settings from the manufacturer are used for the assembly.
The starting pressure of the safety valve must be identical to the maximum allowed pressure
of the tank, and at least 20 % higher than the maximum pressure in the water main (Table
1
1
22
2
33
3
1
1
2 2
2
3 3
3
RR
R
RR
R
L1 L2L3 123 4 5 67 8N 910
PE
L2L3 123 4 5 67 8N 910
L2L3 123 4 5 67 8N 9 10
L1 L2 L3 1 2 3 4 5 6 7 8
N910
L1 L2 L3 1 2 3 4 5 6 7 8
N910

- 17 -
6). If the water main pressure exceeds that value, reduction valve must be added to the
system. No closing armature may be mounted between the 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 regular operation, such a check needs to be carried
out at least once a month, and after each shutdown of the tank longer 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
tank, use the recommended drain valve. First of all, close water inlet in the tank.
Find necessary pressure values in the below Table 6. For proper safety valve operation, a backflow valve
shall be mounted on the inlet pipes, preventing spontaneous heater draining of the tank and hot water
penetration back into the water main. We recommend that the hot water distribution from the tank is as
short as possible in order to reduce 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.
Tanks must be provided with discharge valve mounted on the cold sanitary water inlet to the tank for
potential disassembly or repair.
When assembling the security equipment, follow the standard.
Table 6
SAFETY VALVE
START-UP
PRESSURE
[MPa]
ACCEPTABLE
OPERATING
OVER-
PRESSURE OF
WATER TANK
[MPa]
MAXIMUM
PRESSURE IN
COLD WATER
PIPES [MPa]
0.6
0.6
up to 0.48
0.7
0.7
up to 0.56
1
1
up to 0.8

- 18 -
2.4 PRESSURE LOSSES
Table 7
2.5 EXAMPLES OF CONNECTING TANKS
Connecting a tank to heating system
Type
Pressure loss (mbar)
tHV = 60 °C
Amount of heating water in m3/hr
1
2
3
4
5
Heat exchanger
1 m2
7
27
61
109
170
Heat exchanger
1.5 m2
12
50
108
192
300
Heating water resistance
mbar
Heat exchanger with 1.5 m2
Heat transfer surface 1 m2
Heating water flow m3/hr

- 19 -
The tank is placed on the floor next to the heating source or in its proximity. The heating circuit is
connected to marked tank exchanger inputs and outputs, and bleeder valve is installed at the highest point.
It is necessary to install a filter into the circuit in order to protect pumps, three-way valve, 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 is to work with primary heating of HSW (hot sanitary water) by means of a three-way valve,
follow the fitting instructions of the three-way valve manufacturer.
Connecting a tank to HSW system
Cold water shall be connected to an inlet marked with a blue ring and writing “HSW INLET”. Hot water is
connected to outlet marked with red circle or inscription "HSW OUTLET". If the hot service water (HSW)
distribution is equipped with circulation circuit, it shall be connected to the outlet marked with
“CIRCULATION”. "T" plumbing with discharge valve has to be mounted on HSW inlet in order to drain the
tank. Each independently closing tank must be on the hot water inlet provided with a closure, test tap,
safety valve with backflow flap and manometer.
Example of group connection of tanks by Tichellman method for equal HSW withdrawal of from all tanks
OV –Heating water TUV - Hot sanitary water
SV - Cold water 1 - Return valve
C –Circulation 2 –Pump
Figure 10

- 20 -
OKC 160-300 NTR
heated by gas boiler with two pumps
Figure 11