Danfoss Akva Vita TDP Operating instructions

Brand: Danfoss

Model: Akva Vita TDP

Type: Operating instructions

Instructions

Akva Vita TDP

District heating ﬂat station for direct heating

and domestic hot water systems

DH-SMT/PL

VI.KR.W1.02 © Danfoss 09/2006 1

Akva Vita TDP

Table of contents Akva Vita TDP ................................................. 1

Table of contents ............................................ 1

Safety notes .................................................... 2

Delivery ........................................................... 2

Transport and storage ................................... 2

Mounting ........................................................ 3

Pipes connections ............................................ 4

Electrical connection ........................................ 4

Filling, start-up ................................................. 4

Control ............................................................ 5

Maintenance ................................................... 8

Troubleshooting DHW ................................... 9

Troubleshooting HE ....................................... 10

Akva Vita TDP - district heating ﬂat station for direct HE and DHWInstructions

DH-SMT/PL

VI.KR.W1.02 © Danfoss 09/20062

Safety notes

Following instructions refer to the standard

design of the Akva Vita TDP flat station.

Special versions of ﬂat stations are available

on request.

To avoid injury of persons and damages to the

device, it is absolutely necessary to carefully read

and observe these instructions.

Necessary assembly, start-up and maintenance

work must only be performed by qualiﬁed and

authorized personnel.

Please comply with the instructions of the system

manufacturer or system operator.

Unused connections and shut-oﬀ valves must be

sealed with a plug. The plugs can be removed by

an authorized service technician only.

Warning of high pressure and temperature

The maximum temperature of the ﬂow medium in

a ﬂat station is 90 °C.

The maximum operating pressure of the ﬂat station

is 16 bar.*

* With built-in zone valve 10 bar

Be aware of the installation’s permissible system

pressure and temperature.

The risk of persons being injured and equipment

damaged increases considerably if the

recommended permissible operating parameters

are exceeded.

The ﬂat station installation can be equipped with

safety valve, however, always in accordance with

local regulations.

Warning of hot surface

The ﬂat station has got hot surfaces, which can

cause skin burns. Please be extremely cautious in

close proximity to the ﬂat station.

Warning of transport damage

Before installation of ﬂat station, please make sure

that the ﬂat station has not been damaged during

transport.

Sound level

≤ 55 dB

Corrosion protection

All pipes and components are made of stainless

steel and brass.

The maximum chloride compounds of the ﬂow

medium should not be higher than 300 mg/l.

The risk of equipment corrosion increases

considerably if the recommended permissible

chloride compounds are exceeded.

Delivery The Akva Vita TDP ﬂat station is delivered without

cover as a standard.

Optional ﬂat station equipment:

- safety valve and non-return valve (DCW),

- ﬁtting piece and connections pipe for DCW

meter,

- thermostatic by-pass with return temperature

limiter 10/50 °C for by-pass function (DH),

- connection pipe for circulation with adjustable

setting of DHW circulation,

- electronic programmable room thermostat,

- zone valve with actuator,

- ball valves, all connections G ½“ or G ¾”,

- heat meter (DH supply),

- air screw (DH supply),

- white-lacquered steel sheet cover.

Standard delivery:

The ﬂat station is prepared for by-pass or DHW

circulation control. Equipment for by-pass or DHW

circulation control is optional equipment and must

be ordered separately.

In case of DHW circulation control remember to

mount circulation pump and non-return valve

(this is not part of the delivery and must be ﬁtted

remotely on site).

Transport and storage If the ﬂat station is stored before installation in a

warehouse or any other room, make sure that the

place is dry and heated.

During transport of the ﬂat station to an installation

place it is recommended to lift it with special straps

attached to the bottom (by ﬂat station support

construction).

Instructions

DH-SMT/PL

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Akva Vita TDP - district heating ﬂat station for direct HE and DHW

Mounting

The ﬂat station must be installed and connected

by authorized service personnel.

Installation must be in compliance with the local

standards and regulations.

Allow for adequate space around the ﬂat station

for mounting and maintenance purposes.

Prior to the Akva Vita TDP installation all ﬂat station

pipes and connections should be cleaned and

rinsed.

Due to vibrations during transport all connections

must be checked and tightened before the ﬂat

station is installed.

The picture shows Akva Vita TDP ﬂat station with

by-pass control. Switching to DHW circulation

control is possible from a constructional point of

view, requiring only an additional connection pipe

incl. ﬁttings.

Control change from by-pass to circulation

- Loosen nut (1) on the left-hand side of brass

connection piece between PM controller and

plate heat exchanger, remove blind plate and

mount connection pipe for circulation (optional

feature).

- Remove conical screw (2) (4 mm) on the

right-hand side of the brass connection

piece between PM controller and plate heat

exchanger.

- Loosen and move capillary tube with union nut

from pos. 3 (back of T-piece) to pos. 2.

- Screw the conical screw from pos. 2 (4 mm) on

to the muﬀ at pos. 3.

- Connect circulation installation system with

connection pipe for circulation.

- Remember pump assembly and non-return

valve mounting in the circulation installation

system (not part of the delivery).

The pump must pump water in direction towards

the ﬂat station.

Heat meter assembly, ﬁtting piece

The ﬂat station is equipped with a ﬁtting piece for

insertion of heat meter.

Assembly of heat meter

- Loosen nuts from ﬁtting piece, remove ﬁtting

piece and replace with heat meter.

- Mount the heat meter according to the medium

ﬂow direction. After mounting of heat meter

remember to check all threaded connections.

DCW meter

As an option the ﬂat station can be equipped with a

ﬁtting piece and connection pipe for DCW meter.

Assembly of DCW meter

Please refer to above assembly instructions for heat

meter

Akva Vita TDP - district heating ﬂat station for direct HE and DHWInstructions

DH-SMT/PL

VI.KR.W1.02 © Danfoss 09/20064

Pipes connections

Internal installation and district heating* pipes

connections must be made by means of ﬂanged,

threaded or welded connections.

Connections:

1 District heating (DH) supply

2 District heating (DH) return

3 Domestic cold water (DCW)

4 Domestic hot water (DHW)

5 Heating (HE) supply

6 Heating (HE) return

7 Circulation - optional

8 Domestic cold water (DCW)**

** if DCW meter is mounted:

3 DCW - outlet

8 DCW - inlet

Connection sizes:

DH + DCW + DHW + HE: G ½” or G ¾”

(ext. thread)

Optional Circulation: G ½” (ext. thread)

Dimensions (mm):

Without cover: H 470-590 x W 360 x D 270

With cover: H 490-590 x W 410 x D 320

* District heating (DH) - In the following

DH is speciﬁed as the heat source for the

substations. However, also other heat sources

such as an oil or gas boiler or solar heating

etc. could be used as the primary supply for

the ﬁtted substations, enabling the Danfoss

Redan substations to be used in numerous

schemes with diﬀerent energy sources,

depending on the local operating conditions.

In order to simplify we have decided to use

DH as designation for the primary supply.

Electrical connection The ﬂat station needs no electrical installation to

the main supply or earth grounding.

Filling, start-up Prior to the Akva Vita TDP installation all its pipes

and connections should be cleaned and rinsed.

Before starting-up, check if:

- pipes are connected according to the circuit

diagram,

- release valves are shut-oﬀ,

- threaded connections are tightened.

The heat exchanger must be ﬁlled with water

so that the pressure slowly reaches the working

pressure.

After that the shut-oﬀ valves should be opened

and the operation of the heat exchanger must be

observed (e.g. temperatures, pressure, thermal

expansion, leakages). If the heat exchanger operates

operates unproblematically, it can be taken into

continuous use.

All Danfoss heat exchangers and ﬂat stations have

been pressure tested prior to delivery.

Instructions

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Akva Vita TDP - district heating ﬂat station for direct HE and DHW

Control

1. Diﬀerential pressure controller

The diﬀerential pressure controller reduces the

ﬂuctuating pressure in the district heating network

to a small and invariable operating pressure in

the ﬂat station. The required room temperature

is controlled on your radiator thermostats (ﬁxed

setting throughout the year). It is recommended that

all radiators are opened a little in each room.

The ﬂat station can be equipped with dp controller

type TD200 or AVPL, depending on customer

demand.

TD200

The diﬀerential pressure controller is preset from

factory and should not be adjusted afterwards.

AVPL

The AVPL must be mounted in the return. The dp

controller can be set at any diﬀerential pressure

between 5 kPa and 25 kPa (0,05 bar and 0,25 bar).

The dp controller is preset on 10 kPa (0,1 bar) and

can be adjusted afterwards.

2. HE temperature control

The HE temperature in the house is controlled

by radiator thermostats. As an option the Akva

Vita TDP ﬂat station can be equipped with an

electronic programmable room thermostat

and a zone valve with actuator. In this case

temperature is controlled by the room thermostat

and radiator thermostats. Please note that the room

thermostat keeps the temperature in the whole

apartment according to setting room parameters.

Consult additional maintenance instructions for

room thermostat for further information. It is

recommended to avoid fully opened thermostats

on some radiators and fully shut-oﬀ thermostats

on others. Higher temperature at the top and lower

temperature at the bottom part of radiators means

that the system operation is correct. To keep correct

temperature and friendly microclimate for human

beings in the apartment, it is recommended to

ensure regular airing in rooms.

Akva Vita TDP - district heating ﬂat station for direct HE and DHWInstructions

DH-SMT/PL

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3. DHW temperature control

The DHW temperature is controlled by a

proportional valve – the PM controller. The DHW

temperature control is realized by turning the

lever towards the red (hot) or blue (cold) mark. The

temperature should be set to 45-48 °C at normal

use (7-8 l/min). The temperature should never

exceed 55 °C to avoid lime scale precipitation in

the heat exchanger.

If it is not possible to set the temperature according

to the above recommendations, it is recommended

to change the standard controller setting.

PM controller

The PM controller can operate in three basic

settings:

- High

- Standard – default

- Low

Approximate setting of PM controller is dependent on

district heating supply temperature and ∆p:

Supply

temperature:

Disposable diﬀerential

pressure ∆p (bar):

0.2 - 0.5 0.5 -1.0 > 1.0

60 - 70 °C low low standard

70 - 80 °C low standard standard

80 - 90 °C low high high

Setting changes:

- dismount lever by using the attached Allen

wrench,

- remove plastic cap,

- mount lever again and turn it:

- 1 rotation clockwise – high,

- 1 rotation counter – clockwise – low,

- mount cap and lever again.

Instructions

DH-SMT/PL

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Akva Vita TDP - district heating ﬂat station for direct HE and DHW

Thermostatic by-pass (optional)

As an option the ﬂat station can be equipped

with a by-pass thermostat, Danfoss FJVR, which

ensures that hot water is available immediately

when tapping starts. It is recommended to set

the thermostat in pos. 3. If the water temperature

rises too slowly it can be necessary to set the

thermostat at higher value, however, not higher

than in position 4.

DHW circulation (optional)

As an option the ﬂat station can be equipped with

connection pipe for circulation with adjustable

setting of DHW circulation. If the Akva Vita TDP

ﬂat station is connected to the circulation system

in the building, the thermostat will control the

circulation water temperature. This ensures that

hot water is available at the tap point without any

waiting time and water waste. It is recommended

to set the thermostat in pos. 2-2,5. If the circulation

pump is switched oﬀ, the thermostat should be

closed. In case the Akva Vita TDP ﬂat station has

been delivered with by-pass control and this must

be changed to DHW circulation, this can be done

by performing control change from by-pass to

circulation, as described on page 3.

Approximate thermostat scale setting:

I = 10 °C

1 = 20 °C

2 = 30 °C

3 = 40 °C

4 = 45 °C

I = 50 °C (max. temp.)

4. Safety valve (optional)

The safety valve’s task is to protect the ﬂat station

from pressures exceeding the permissible pressure.

The blow-oﬀ pipe of the safety valve must not be

closed. The blow-oﬀ pipe outlet should be placed

so that it provides safety relief and it is possible to

observe water dropping from the safety valve. It

is advisable to check the operation of the safety

valve by turning the valve head into the indicated

direction, every six months.

5. Filters

Filters should frequently be cleaned from sediments

by authorized personnel, according to producer’s

instructions and depending on the ﬂat station’s

operating conditions.

Akva Vita TDP - district heating ﬂat station for direct HE and DHWInstructions

DH-SMT/PL

VI.KR.W1.02 © Danfoss 09/20068

Maintenance

It is necessary to check and maintain the ﬂat

station on a regular basis in order to keep it in

good operating condition.

The frequency of the maintenance and service

inspections should be according to system

manufacturer speciﬁcations and local legislation.

However, maintenance inspections should take

place at least twice each year (before and after the

heating season).

In addition to the check of the ﬂat station as to its

functionality, it is also recommended to check if the

following system parameters are compliant with

the requirements of the system manufacturer and

local regulations:

- no leakages,

- correct temperatures in the distribution

network,

- stable district heating supply and return

temperatures,

- correct cooling of the district heating supply,

- DHW temperature (requested temperature

should be in accordance with the local

regulations),

- pressure drops in ﬁltering and water

conditioning plants (ﬁlters, sludgers etc.),

- pressure drops in the heat exchanger (primary

and secondary side of heat exchanger).

The ﬂat station operator should consider the above

parameters and prepare written maintenance

reports.

Service inspections by authorized personnel

are usually more precise (complex) than user

maintenance inspections and the intervals between

them are longer.

Instructions

DH-SMT/PL

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Akva Vita TDP - district heating ﬂat station for direct HE and DHW

Troubleshooting

DHW

Problem Possible cause Solution

In general: Does the PM

controller work incorrectly?

If the quantity of tapping water

is normal (temperature

unimportant) it indicates that the

PM controller works correctly.

Locate defect in another part

of the installation

(see below)

In general: Are the operating

conditions satisfactory?

The ﬂat station requires a DH

supply temperature of minimum

60 °C and a diﬀerential pressure

during operation according to the

information stated in the product

sheet for Akva Vita TDP.

Contact district heating

supplier.

PM controller leaking;

Water leaking from Allen

screws

at the central part of

PM controller.

One of the two O-rings is defective

(does not inﬂuence the PM

operation). If a non-return valve is

installed in the DCW inlet (e.g. in

the house service connection or in

DCW meter) a safety valve should be

mounted between the non-return

valve and the heat exchanger.

Replace PM controller

(use new sealing).

DHW tap load too low

The diaphragm of the PM controller

is defective.

Replace diaphragm

or PM controller.

DHW tap load too low;

Tap temperature too low;

Tap temperature ﬂuctuates;

PM controller wrongly

adjusted,

Strainer on DH supply clogged,

Defective non-return valve in

thermostatic battery (DHW tap

temperature lower than DHW from

ﬂat station),

Defective non-return valve in hot-

water circulation (circulation return

pipe is getting cold during tapping

of hot water),

Lime scale precipitation in

plate heat exchanger for DHW

(primary Δt too low during DHW

tapping),

Dirt in PM controller,

DCW ﬂow too high (big nominal

diameter of pipe, high DCW

pressure), in total max. 16-17 litres

per minute.

Setting, see Regulation

chapter.

Clean strainer.

Clean or replace non-return

valve.

Clean or replace non-return

valve.

Replace the plate heat

exchanger.

Cleaning, see PM controller

instruction.

DCW reduction.

DH return water temperature

too high while on standby;

The plate heat exchanger is

cold…

The by-pass thermostat is defective

or wrongly adjusted.

Replace or adjust by-pass

thermostat correctly

DH return water temperature

too high while on standby;

The plate heat exchanger is

hot…

Dirt (sand, iron splinters or similar)

in PM controller. Controller does not

close. Noise from ﬂow can often be

heard.

Move handle several times

between red and blue

markings; at the same

time do several hot-

water tappings. Clean PM

controller.

DH return temperature

too high during hot water

tapping.

Lime scale precipitation in the plate

heat exchanger for DHW

Replace plate heat exchanger

Connecting pieces of the PM

controller do not ﬁt the ﬂat

station

In particular when replacing PM

controller in old ﬂat station

Loosen Allen screws; turn

half of the PM controller 180°

Danfoss Redan A/S

Sindalsvej 33-35

DK-8240 Risskov, Denmark

Phone: +45 87 43 89 43

Fax: +45 87 43 89 44

redan@danfoss.com

www.redan.danfoss.dk

Akva Vita TDP - district heating ﬂat station for direct HE and DHWInstructions

DH-SMT/PL

Troubleshooting

If operating disturbances occur, the following basic

features should be checked before carrying out

actual trouble shooting:

- the substation is connected to electricity

(applies only to substations with room

thermostat),

- the strainer on the district heating supply pipe

is clean,

- the supply temperature of the district heating

is at the normal level (summer, at least 60 °C

- winter, at least 70 °C),

- the diﬀerential pressure is higher than or equal

to the normal (local) diﬀerential pressure in the

district heating network – if in doubt, ask the

district heating plant,

- there is pressure on the system.

Problem Possible cause Solution

No heat

Strainer clogged on DH or HE side

(radiator circuit).

Strainer in the district heating meter

clogged.

Defective or wrongly adjusted

diﬀerential pressure controller.

Defective room thermostat/actuator

- or possibly dirt in the zone valve

housing.

Air pockets in the system.

Clean gate/strainer.

Clean the strainer (after

consulting the district

heating plant).

Check the operation of the

diﬀerential pressure

controller – clean the valve

seat if required.

Check the operation of the

room thermostat/actuator

- clean the zone valve seat if

required.

Air the installation

thoroughly.

Uneven heat

distribution

Air pockets in the system.

Air the installation

thoroughly

Supply temperature

too low

Strainer clogged. Clean gate/strainer.

Poor cooling

Too small heating surface/too small

radiators in relation to the total

heating requirement of the building.

Poor utilization of existing heating

surface.

The system is single-pipe.

Increase total heating

surface.

Make sure the heat is

distributed evenly across

the full heating surface. It is

recommended to avoid fully

opened thermostats on some

radiators and fully shut-

oﬀ thermostats on others.

Higher temperature at the

top and lower temperature at

the bottom part of radiators

means that the system

operation is correct.

It is extremely important to

keep the supply temperature

to the radiators as low as ever

possible, while maintaining a

reasonable level of comfort.

Danfoss Akva Vita TDP Operating instructions

Danfoss Akva Vita TDP Operating instructions

Danfoss Akva Vita TDP Operating instructions

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