Drazice OKCE 160 NTR Specification sheet

OPERATION AND
INSTALLATION MANUAL
STATIONARY ELECTRIC WATER HEATERS
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
tel.: +420 / 326 370 990
fax: +420 / 326 370 980
e-mail: [email protected]

- 2 -
CONTENT
1TECHNICAL SPECIFICATION OF PRODUCT .................................................................................................4
1.1 FUNCTION DESCRIPTION ................................................................................................................... 4
1.2 PRODUCT DESCRIPTION .................................................................................................................... 4
1.3 CONSTRUCTION AND GENERAL HEATER DIMENSION....................................................................... 5
1.4 TECHNICAL PARAMETERS.................................................................................................................. 9
2 OPERATION AND FITTING INSTRUCTION.................................................................................................13
2.1 OPERATING CONDITIONS ................................................................................................................ 13
2.2 ELECTRIC INSTALLATION.................................................................................................................. 13
2.2.1 TECHNICAL PARAMETERS OF AN ELECTRIC HEATING UNIT .................................................... 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 HEATERS CONNECTION............................................................................................ 18
2.6 PUTTING THE HEATER INTO OPERATION ........................................................................................ 22
2.7 HOT SERVICE WATER TEMPERATURE CONTROL ............................................................................. 22
2.7.1 HSW TEMPERATURE CONTROL FOR 300 LITRE HEATERS........................................................ 22
2.7.2 HSW TEMPRERATURE CONTROL FOR 160 – 250 LITRE HEATERS............................................ 23
2.8 HEATER CLEANING AND ANODE ROD EXCHANGE........................................................................... 24
2.9 SPARE PARTS.................................................................................................................................... 25
3 IMPORTANT NOTICES .............................................................................................................................. 25
3.1 INSTALLATION REGULATIONS.......................................................................................................... 25
3.2 DISPOSAL OF PACKAGING MATERIAL AND FUNCTIONLESS PRODUCT ........................................... 26

- 3 -
Meaning of pictograms used in Manual
Important information for heater users.
Recommendations of manufacturer, observance of which will ensure trouble-free
operation and long service life of the product.
CAUTION!
Important notice to be observed.
READ CAREFULLY THE BELOW INSTRUCTIONS PRIOR TO THE INSTALLATION THE
HEATER!
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 water heaters.
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 -
1TECHNICAL SPECIFICATION OF PRODUCT
1.1 FUNCTION DESCRIPTION
Thanks to their construction and number of variants, the OKC 160– 300 series water heaters 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 heater tank 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. For additional corrosion protection a magnesium anode is
mounted in the upper part of the heater to adjust the electric potential inside the tank, reducing the risk of
corrosion. All types have the 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 heater shell consists of a steel,
powder-paint coated, sheet; the connecting parts are metal coated. The entire heater stands on three
rectification screws with a possibility of levelling floor unevenness within the range of 10 mm. Under a
plastic cover on the side of the heater, there is a cleaning and revision opening ended with a flange; various
performance heating units may be mounted into the opening. The NTR and NTRR series heaters from 200
litre volume are equipped with a 6/4“ aperture for in-screwing an additional TJ heating element. Such
version is use
d when the heater is connected to either a solar system or a system with a heat pump, to
reheat water in the upper part of the heater to the temperature required. The heater is to be placed on the
ground. The tank is tested with pressure of 0.9 Mpa, heat exchanger with 1.5 Mpa.
The NTR version has a heat exchanger located in the bottom part of the heater, and one heating water
source is used 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. Heater cannot be used for flow heating of hot water in an exchanger.

- 5 -
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
A1052 1362 1542
B969 1282 1462
C652 952 1062
E - 813 813
F782 782 782
G212 212 212
H82 82 82
A 160 l capacity heater does not feature a G 6/4" opening.
Type
1.3 CONSTRUCTION AND GENERAL HEATER DIMENSION
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 25 NTR/BP
Figure 1

- 6 -
OKCE 200 NTRR/2,2 kW OKCE 250 NTRR/2,2 kW
OKC 200 NTRR/BP OKC 250 NTRR/BP
A1362 1542
B1282 1465
C862 1065
D922 1002
E712 895
F1152 1335
G212 215
H82 85
I652 655
Type
OKCE 200 NTRR/2,2 kW, OKCE 250 NTRR/2,2 kW, OKC 200 NTRR/BP, OKC 250 NTRR/2,2 BP
Figure 2

- 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
TYPE OKCE 160 NTR/2,2kW OKC 160 NTR/BP
CAPACITY [l] 155
WEIGHT OF THE HEATER [kg] 88 77
OPERATING PRESSURE IN THE
TANK [MPa]
0,6
OPERATING OVERPRESSURE IN THE
EXCHANGER [MPa]
1
MAX HEATING WATER
TEMPERATURE [°C]
110
MAX TEMPERATURE OF HSW1[°C] 80
LOWER EXCHANGER HEAT DELIVERY
SURFACE [m2] 1,45
BOTTOM EXCHANGER OUTPUT AT
HEATING WATER TEMPERATURE OF
80 °C AND FLOW 720 l/h [kW]
32
PERMANENT HSW1OUTPUT OF
LOWER EXCHANGER [l/h] 990
TIME OF HEATING BY EXCHANGER
FROM 10°C TO 60 °C [min] 17
TIME OF HEATING WITH ELECTRICITY
FROM 10°C TO 60 °C [h] 4,5
POWER INPUT [kW] 2,2 -
ELECTRIC CONNECTION OF CONTROL
ELEMENTS 1 PE-N 230 V/50 Hz
IP PROTECTION IP 44
1HSW – Hot service water 45 °C
2These data do not apply to those NTR/BP types that do not have a heating element.
Table 1

- 10 -
TYPE OKCE 200
NTR/2,2kW
OKC 200
NTR/BP
OKCE 200
NTRR/2,2 kW
OKC 200
NTRR/BP
CAPACITY [l] 200 195
WEIGHT OF THE HEATER kg] 95 92 106 103
OPERATING PRESSURE IN THE
TANK [MPa] 0,6
OPERATING OVERPRESSURE IN
THE EXCHANGER [MPa] 1
MAX HEATING WATER
TEMPERATURE [°C] 110
MAX TEMPERATURE OF
HSW1[°C] 80
LOWER EXCHANGER HEAT
DELIVERY SUFRACE [m2] 1,45 1,08
UPPER EXCHANGER HEAT
DELIVERY SURFACE [m2] - 1,08
BOTTOM/TOP EXCHANGER
OUTPUT AT HEATING WATER
TEMPERATURE OF 80 °C AND
FLOW 720 l/h [kW]
32 2 x 24
PERMANENT HSW1OUTPUT OF
LOWER/UPPER EXCHANGER
[l/h]
990 670/650
*1080
TIME OF HEATING BY
EXCHANGER FROM 10°C
TO 60 °C [min]
22 28 16
TIME OF HEATING WITH
ELECTRICITY FROM 10°C
TO 60 °C [h]
5,5
POWER INPUT2[kW] 2,2 - 2,2 -
ELECTRIC CONNECTION OF
CONTROL ELEMENTS 1 PE-N 230 V/50 Hz
IP PROTECTION IP 44
1 HSW – Hot service water 45 °C
2 These data do not apply to those NTR/BP types that do not have a heating element
* Exchangers combined in a series
Table 2

- 11 -
TYPE OKCE 250
NTR/2,2kW
OKC 250
NTR/BP
OKCE 250
NTRR/2,2 kW
OKC 250
NTRR/BP
CAPACITY [l] 250245
WEIGHT OF THE HEATER [kg] 106 103 116 112
OPERATING PRESSURE IN THE
TANK [MPa] 0,6
OPERATING OVERPRESSURE IN
THE EXCHANGER [MPa] 1
MAX HEATING WATER
TEMPERATURE [°C] 110
MAX TEMPERATURE
OF HSW1 [°C] 80
LOWER EXCHANGER HEAT
DELIVERY SURFACE [m2] 1,45 1,08
UPPER EXCHANGER HEAT
DELIVERY SURFACE [m2] - 1,08
BOTTOM/TOP EXCHANGER
OUTPUT AT HEATING WATER
TEMPERATURE OF 80 °C AND
FLOW 720 l/h [kW]
32 2 x 24
PERMANENT HSW1OUTPUT
OF LOWER/UPPER
EXCHANGER [l/h]
990 670/650
*1080
TIME OF HEATING BY
EXCHANGER FROM 10°C
TO 60 °C [min]
28 36 20
TIME OF HEATING WITH
ELECTRICITY FROM 10°C
TO 60 °C [h]
6,5
POWER INPUT2[kW] 2,2 - 2,2 -
ELECTRIC CONNECTION OF
CONTROL ELEMENTS 1 PE-N 230 V/50 Hz
IP PROTECTION IP 44
1 Hot service water 45 °C
2 These data do not apply to those NTR/BP types that do not have a rating element.
* Exchangers combined in a series
Table 3

- 12 -
TYPE
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] 300 295
WEIGHT OF THE
HEATER [kg]
116 122 111 150 155 148
OPERATING PRESSURE IN
THE TANK [MPa] 0,6
OPERATING
OVERPRESSURE IN THE
EXCHANGER [MPa]
1
MAX HEATING WATER
TEMPERATURE [°C] 110
MAX TEMPERATURE OF
HSW1[°C] 80
LOWER EXCHANGER HEAT
DELIVERY SURFACE [m2] 1,08
UPPER EXCHANGER HEAT
DELIVERY SURGACE [m2] 1,08
BOTTOM/TOP
EXCHANGER OUTPUT AT
HEATING WATER
TEMPERATURE OF 80 °C
AND FLOW 720 l/h [kW]
35 27
PERMANENT HSW 1
OUTPUT OF
LOWER/UPPER
EXCHANGER [l/h]
1100 760
TIME OF HEATING BY
EXCHANGER FROM 10°C
TO 60 °C [min]
24 16
TIME OF HEATING WITH
ELECTRICITY FROM 10°C
TO 60 °C [h]
8,5/6,3
POWER INPUT2[kW] 2,2 3-6 - 2,2 3-6 -
ELECTRIC CONNECTION
OF CONTROL ELEMENTS 1 PE-N 230 V/50 Hz
IP PROTECTION IP 44
1 Hot service water 45 °C
2 These data do not apply to those NTR/BP types that do not have a rating element.
* Exchangers combined in a series
Table 4

- 13 -
2OPERATION AND FITTING INSTRUCTION
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 heater 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 60oC (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.
300 litre capacity heaters are screwed onto the bottom wooden palette with M12 screws.
When the heater is released from the palette and prior to its putting into operation, 3
adjustable legs supplied as the product accessories have to be installed. With these legs, the
heater may be positioned vertically to the base, within 10 mm.
2.2 ELECTRIC 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 heater is with a universal electric heating unit with either set or adjustable heating element
performance. A heating unit consists of a flange, to which one or three wells for ceramic heating elements
and one thermowell are welded (see fig.). A unit is attached by either 8 M10 screws with a 168 mm
clearance, or 12 M12 screws with a 210 mm clearance. In the wiring plastic cover, there is a thermostat and
a safety fuse; heater operation control light; and a lead-in wire 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 TECHNICAL PARAMETERS OF AN ELECTRIC HEATING UNIT
Heating unit
2,2 kW
Universal heating unit 3–6 kW
PERFORMANCE
(kW)
2,2 3 3 46
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
IP PROTECTION
IP 44
NUMBER OF
HEATING
ELEMENTS
13
PERFORMANCE
OF ONE
HEATING
ELEMENT (kW)
2,2 2
Table 5
After the heater is connected to electric network, the heating element starts heating water. The element is
turned on and off by a thermostat. Thermostat can be set as per your need within the range from 5°C to
74°C.
We recommend setting the service water temperature to maximum temperature of 60°C.
This temperature ensures an optimal operation of the heater, reduces heat losses and
saves electricity.
After reaching the temperature set, the thermostat switches off the electric circuit and this 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). When putting the heater out of service for an extended period, in winter you can set the thermostat
to the “snowflake” symbol preventing the water from freezing, or turn off the electricity supply to the
heater.
Connection, repairs, and wiring inspections may only be implemented by company
(person) authorised to such activity.
The heater is connected to the electric network using a solid 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 heater is IP 44.
The electric installation must follow and meet the requirements and regulations relevant in the country
of use!

- 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 5 Figure 6
OKCE 300 NTR/3-6 kW, OKCE 300 NTRR/3-6 kW Electric installation guard and wiring scheme
Heater operation Control voltage 230 V/50 Hz
Thermostat control light
Fastening 12 x M12
Figure 7 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“.Blue – cold water supply, red – hot water outlet.
For potential disconnection of the heater, 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 heater must have a membrane spring loaded with a safety
valve. Nominal clearance of safety valves is defined by standard.The safety valve must be
easily accessible, as close to the heater 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 heater. 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 heater pressure and at least 20
% higher than the maximum pressure in the water main (Table 6). 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 heater and the safety valve. During the assembly, follow the guide
provided by the safety equipment manufacturer.
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 910
L1 L2 L3 1 2 3 4 5 6 7 8
N9
10
L1 L2 L3 1 2 34 5 6 7 8
N9
10

- 17 -
Please find necessary pressure values in the below Table 6. For proper safety valve operation, a backflow
valve must be mounted on the inlets pipes, preventing spontaneous heater draining and hot water
penetrating back into the water main. We recommend that the hot water distribution from the heater 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.
Heaters must be provided with a discharge valve mounted on the cold service water inlet to the heater for
potential disassembly or repair.
When assembling the security equipment, follow the standards.
Table 6
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 heater 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
heater, use the recommended drain valve. First, close the water supply into the heater.
SAFETY VALVE
OPERATING
PRESSURE
[MPa]
ADMISSIBLE
OPERATING
WATER
HEATER
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

- 18 -
2.4 PRESSURE LOSSES
Type
Pressure loss mbar
tHV = 60 °C
Amount of rating water in m3/h
1
2
3
4
5
Exchanger 1 m
2
727 61 109 170
Exchanger 1.5 m
2
12 50 108 192 300
2.5 EXAMPLES OF HEATERS CONNECTION
Connecting a heater to a rating circuit
The heater 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 heater exchanger; the deaerating 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.
Heating water flow m3/hour
Exchanger with 1.5 m2
heat transfer surface
Exchanger with 1 m2
heat transfer surface
Heating water resistence
mbar

- 19 -
Connecting a heater 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)
distribution is equipped with circulation circuit, it shall be connected to the outlet marked with
“CIRCULATION”. For potential drain of heater, the HSW inlet has to be provided with a “T” fixture with a
drain valve. Each individually lockable heater 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 heater connection for steady hot water consumption from all tanks using
Tichelmanns´s method
HW – heating water HSW – hot service water
CW – cold water 1 – Return valve
C - circulation 2 - pump
Figure 10

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