PAW FriwaMidi-DN 20 User manual

PAW GmbH & Co. KG
Böcklerstr. 11, D-31789 Hameln, Germany
Phone: [phone], Fax: [phone]
E-mail: [email protected], Web: www.paw.eu
2016/07 99640x6xx-mub-de –V08 1
Installation and Operation Instructions
Domestic hot water modules
FriwaMidi –DN 20
FriwaMaxi –DN 25

1General Information
2 99640x6xx-mub-de –V08 2016/07
Contents
1General Information.........................................................................................................3
1.1 Scope of these instructions .......................................................................................... 3
1.2 About this product ........................................................................................................ 4
1.3 Designated use ............................................................................................................ 4
2Safety instructions ...........................................................................................................5
3Product description..........................................................................................................7
4Dimensioning and planning..............................................................................................8
4.1 Dimensioning of the tank.............................................................................................. 9
5Circulation mode ...........................................................................................................10
6Assembly and installation [specialist]..............................................................................11
7Commissioning [specialist].............................................................................................14
7.1 Filling the primary circuit............................................................................................. 15
7.2 Commissioning of the controller ................................................................................. 16
7.3 Maximum withdrawal flow rate ................................................................................... 18
7.4 Setting the temperature.............................................................................................. 20
8Maintenance [specialist].................................................................................................21
9Spare parts [specialist] ..................................................................................................22
9.1 Spare parts control and insulation FriwaMidi (6405640 / 6405641)
and FriwaMaxi (6406662 / 6406663).......................................................................... 22
9.2 Spare parts hydraulics FriwaMidi without circulation (6405640) /
with circulation (6405641) .......................................................................................... 23
9.3 Spare parts hydraulics FriwaMaxi without circulation (6406662) /
with circulation (6406663)............................................................................................ 24
10 Technical data...............................................................................................................25
10.1 Pressure drop characteristic curves FriwaMidi ........................................................... 26
10.2 Pressure drop characteristic curves FriwaMaxi .......................................................... 26
11 Commissioning report....................................................................................................27
Item no. 99640x6xx-mub-de - Version V08 –Date 2016/07
Translation of the original instructions
We reserve the right to make technical changes without notice!
Printed in Germany –Copyright by PAW GmbH & Co. KG
PAW GmbH & Co. KG
Böcklerstraße 11
D-31789 Hameln, Germany

1General Information
2016/07 99640x6xx-mub-de –V08 3
1General Information
1.1 Scope of these instructions
These instructions describe the installation, commissioning, function and operation
of the domestic hot water modules FriwaMidi and FriwaMaxi.
The chapters called [specialist] are intended for specialists only.
For other components of the system, such as tanks, controllers or pumps, please observe
the instructions of the corresponding manufacturer.
Item
Item
number
Controller
FC3.8
Pump
primary
Circulation
Heat exchanger
FriwaMidi
6405640
Grundfos
UPM2 25-75
Optional:
Grundfos
UPM2 15-75 CIL2
40 plates
6405641
Grundfos
UPM2 25-75
Grundfos
UPM2 15-75 CIL2
Item
Item
number
Controller
FC3.8
Pump
primary
Circulation
Heat exchanger
FriwaMaxi
6406662
Grundfos
UPML 25-105
Optional:
Grundfos
UPM2 15-75 CIL2
60 plates
6406663
Grundfos
UPML 25-105
Grundfos
UPM2 15-75 CIL2
Carefully read these instructions before installation and commissioning.
Save these instructions in the vicinity of the installation for future reference.

1General Information
4 99640x6xx-mub-de –V08 2016/07
1.2 About this product
The domestic hot water module is a premounted fitting group checked for leakage and
used to transfer the heat between the buffer tank and the domestic hot water circuit.
It contains a preset controller and important fittings for the operation of the system:
Ball valves in the primary circuit
Piston valves in the secondary circuit
Pressure relief valve in the secondary circuit
Premounted controller
Temperature sensor on the cold water inlet
Temperature sensors on the heating flow
Temperature sensor on the domestic hot water outlet
Flow meter on the domestic hot water outlet
Fill and drain valve for draining the heat exchanger
Vent plug for venting the heat exchanger
1.3 Designated use
The domestic hot water module must only be used in heating installations between
the buffer tank and the domestic hot water circuit.
Due to its design, the station must be mounted and operated in a vertical position!
The technical data specified in these instructions must be observed.
Only use PAW accessories with the domestic hot water module.
Improper usage excludes any liability claims.
The wrapping materials are made of recyclable materials and can be disposed of
with recyclable materials.

2Safety instructions
2016/07 99640x6xx-mub-de –V08 5
2Safety instructions
The installation and commissioning as well as the connection of electrical components require
technical knowledge commensurate with a recognised vocational qualification as a fitter for
plumbing, heating and air conditioning technology, or a profession requiring a comparable
level of knowledge [specialist].
The following must be observed during installation and commissioning:
relevant local and national regulations
accident prevention regulations of the professional association
instructions and safety instructions of this manual
WARNING
Danger of scalding due to hot water!
Undesirable circulation of water in the primary circuit can cause the exit of water
of up to 90 °C at the withdrawal point.
External pumps must not be installed between the domestic hot water
module and the buffer tank.
The domestic hot water module must not be connected to a distribution
manifold.
CAUTION
Risk of burns!
The valves, fittings and the pump may heat up to more than 95 °C
during operation.
The insulating shell must remain closed during operation.

2Safety instructions
6 99640x6xx-mub-de –V08 2016/07
NOTICE
Material damage due to mineral oils!
Mineral oil products cause lasting damage to seals made of EPDM, whereby the sealant
properties get lost. We do not assume liability nor provide warranty for damage to property
resulting from sealants damaged in this way.
It is imperative to avoid that EPDM gets in contact with substances containing
mineral oils.
Use a lubricant based on silicone or polyalkylene and free of mineral oils,
such as Unisilikon L250L and Syntheso Glep 1 of the Klüber company or a silicone
spray.
NOTICE
Malfunction!
The domestic hot water module must be integrated in the potential equalisation of
the electric installation. This can be guaranteed by establishing a potential equalisation
connection to the main potential connection according to regulations or by the connected
pipe system.

3Product description
2016/07 99640x6xx-mub-de –V08 7
3Product description
Example: FriwaMaxi with circulation
Connections
1
Primary side: return to the buffer tank
2
Secondary side:
hot water circulation, return
3
Secondary side: cold water inlet
4
Secondary side: hot water outlet
5
Primary side: flow from the buffer tank
Equipment
A
Ball valve with check valve
B
Primary pump
C
Non-return valve with drain valve
D
Circulation pump
E
Piston valve with drain valve
F
Piston valve with drain valve
G
Piston valve with drain valve
and temperature sensor
H
Fill and drain valve
and temperature sensor
I
Flow meter FlowSonic
J
Plate heat exchanger
K
Circulation line
L
Vent valve (primary circuit)
M
Temperature sensor and pressure relief
valve 10 bars, suitable for DHW
Only for the protection of the station.
Does not replace the pressure relief
valve that has to be mounted on site!
N
Ball valve with check valve

4Dimensioning and planning
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4Dimensioning and planning
The FriwaMidi and FriwaMaxi are domestic hot water modules which heat potable
water operating on the principle of a flow-type water heater.
The FriwaMidi and FriwaMaxi can only work flawlessly if the installation meets certain
requirements. Please take some time to plan the installation.
WARNING
Danger of scalding due to hot water!
Undesirable circulation of water in the primary circuit can cause the exit of
water of up to 90 °C at the withdrawal point.
External pumps must not be installed between the domestic hot water
module and the buffer tank.
The domestic hot water module must not be connected to a distribution
manifold.
Mounting example
FriwaMidi with optional circulation set (item no. 640412) and with optional return distribution
(FriwaMidi: item no. 640423, FriwaMaxi: item no. 640424)
Safety group
according to DIN 1988

4Dimensioning and planning
2016/07 99640x6xx-mub-de –V08 9
4.1 Dimensioning of the tank
Thanks to the following table, you can calculate the approximately required volume of
the buffer tank.
Temperature in
the buffer tank
Domestic hot water
temperature set at
the controller
Required tank volume
per litre of hot water
50 °C
45 °C
1.3 litres
60 °C*
45 °C
0.8 litre
50 °C
1.0 litre
55 °C
1.4 litres
70 °C
45 °C
0.7 litre
50 °C
0.8 litre
55 °C
0,9 litre
80 °C
45 °C
0.5 litre
50 °C
0.6 litre
55 °C
0.7 litre
*Calculation example for the dimensioning of the buffer tank:
Temperature buffer tank: 60 °C
Maximum withdrawal quantity needed: 20 l/min
Domestic hot water temperature set at the controller: 45 °C
How large must the tank be to allow for a continuous withdrawal during 20 minutes
without reheating?
20 l/min x 20 min = 400 l
400 l x 0,8 = 320 l
The heated part of the buffer tank must have a volume of 320 litres.

5Circulation mode
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5Circulation mode
The domestic hot water modules FriwaMidi and FriwaMaxi are optionally equipped with
a circulation pump.
The FriwaMidi and FriwaMaxi without circulation can be subsequently equipped with
a circulation set (item no. 640412).
Three different operating modes of the circulation pump are set at the controller
(see controller instructions, menu "Func" / "F02"):
Pulse-controlled operation (depending on the demand / requirements):
The short opening of a hot water tap (tap pulse: ~2 sec.) starts the circulation pump.
The circulation pump will then run for several minutes (adjustable).
Time-dependent operation:
The operation of the circulation pump can be set on a week clock within a freely
selectable period of time. The circulation will start at the beginning of the period
of time chosen. The circulation will stop after the end of the chosen period of time.
Temperature-dependent operation:
In this operating mode, the circulation only starts if the adjustable minimum temperature
on the circulation temperature sensor is not reached during the chosen period of
operation. The circulation stops after the required temperature has been reached
or after the end of the chosen period of time.
The operating modes can be combined with one another as wished, f. ex. the time- and the
temperature-dependent operating modes. The circulation is only active if the temperature at the
circulation temperature sensor falls below the required value and if the time window is active.
Outside the time window, the circulation pump can be started by a tap pulse if the
pulse-controlled operation mode is additionally activated.
NOTICE
Damage to property!
When the Friwa is delivered, the circulation is not activated (see controller instructions, menu:
"Func" / "F02" set to "OFF"). Once the circulation line mounted, it is mandatory to select and
preset the operating mode. The revolution speed of the circulation pump must be determined
by the PWM signal (factory setting: 40 %).