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20

Instructions for installation and use 

TD & S substations

DKDHR 

VI.GP.U2.02 

Danfoss District Energy 

18.  Operation and maintenance

Operation and maintenance

The caretaker/owner must perform visual checking and reading of 

the district heating meter at short, regular intervals. (The meter is 

not a part of the delivery from Danfoss).

Service procedures must only be performed by trained, authorised 

personnel.

NB! Excessive consumption for whatever reason is not covered by 

the Danfoss warranty. 

Service

  

The substation should be checked regularly by authorised person-

nel. Any necessary maintenance must be performed in accordance 

with the instructions in this manual and other sets of instructions. 

During service the dirt strainers are to be cleaned (

pos. 8

 – including 

the filter (

F

) on the controller, see the photo to the right), all pipe 

connections must be tightened and the safety valve (

pos. 5

) must 

be function tested by turning the lever.

Rinsing / Return rinsing

To clean the plate heat exchanger, rinse it by running clean water through 

the exchanger at high speed and in the opposite direction to the normal 

flow. This will remove any dirt deposits that may have built up in the 

exchanger. If rinsing with clean water is not sufficient, the exchanger 

can also be cleaned by circulating a cleaning agent approved by Danfoss 

(e.g. Kaloxi cleaning fluid) through the exchanger. Kaloxi cleaning fluid is 

environmentally friendly and can be disposed off through the standard 

sewer system. After use of a cleaning fluid, the plate heat exchanger must 

be rinsed thoroughly with clean water.

Acid cleaning of brazed plate heat exhanger

In principle, we do not recommend using acid cleaning of the plate 

heat exchanger. Deposits of limescale may build up in plate heat ex-

changers for domestic hot water on account of the large temperature 

fluctuations, and because aerated water is used on the secondary 

side. If it becomes necessary to clean the exchanger with acid, this 

can be done as shown in the figure to the right. Brazed plate heat 

exchangers can withstand rinsing with a dilute acid solution – e.g. 

5% formic acid.

Measures after maintenance work

After maintenance work and before commissioning:

• 

Tighten all pipe connections

• 

Replace insulation covers on heat exchangers and other 

insulated equipment

• 

Wipe down the substation and clean up any fluid spills

• 

Clear all tools, materials and other equipment from the work area

• 

Switch on the energy supply and check for leakage

• 

Vent the system

• 

Carry out any necessary adjustments again.

• 

Check that pressure and temperature are at normal levels.

Cooling / Reading the return temperature

Cooling – i.e. the difference between the supply and return tempera-

ture of the district heating water – has a significant effect on overall 

energy economy. Therefore, it is important to focus on the supply 

and return temperature in the heating system. The difference should 

typically be 30–35°C. Please note that a low district heating return 

temperature is directly related to the return temperature from the 

heating circuit and the return temperature of the circulation water. 

It is therefore important to focus on these return temperatures. 

Cooling from the water heater alone:

During tapping, the level of cooling will typically be 30–35°C. When 

hot water is not being tapped, it is completely normal for the return 

temperature from the water heater to rise slightly. In this situation, 

the district heating meter will register very modest consumption as 

the volume of water is very small. 

On water heaters with recirculation, the calorie meter registers the 

heat loss in the circulation pipe.

Summary of Contents for Akva Vita II TD

Page 1: ...Danfoss District Energy MAKING MODERN LIVING POSSIBLE Akva Vita II TD S Akva Lux II Akva Les II TD S Instructions for installation and use...

Page 2: ...ING STARTED 10 10 Installation instructions general 11 11 Installation instructions specially for S substations 12 12 Installation instructions recirculation connection 13 13 Adjustment and commission...

Page 3: ...Danfoss FJVR Differential pressure controller AVPL Safety valve Fitting piece for meter Thermometer DHW Dirt strainer Sensor pocket White painted cover Filter on cold water supply The unit has been p...

Page 4: ...tic hot water controller PTC2 P Bypass thermostat Danfoss FJVR Differential pressure controller AVPL Safety valve Fitting piece for meter Thermometer hot water Dirt strainer Sensor pocket White painte...

Page 5: ...exchanger brazed domestic hot water Domestic hot water controller PM2 P Bypass thermostat Danfoss FJVR Differential pressure controller AVPL Safety valve Fitting piece for meter Thermometer floor hea...

Page 6: ...Domestic hot water controller PTC2 P Bypass thermostat Danfoss FJVR Differential pressure controller AVPL Safety valve Fitting piece for meter Thermometer floor heating thermometer domestic hot water...

Page 7: ...s and an excessively high return temperature in the district heating circuit poor cooling of the district heating water Cooling i e the difference between the supply and return temperature of the dist...

Page 8: ...ccur noise in the radiator thermostats or poor regulation capacity it may be necessary to reset the differential pressure controller to a lower operating pressure We suggest that you contact your loca...

Page 9: ...mperature in the district heating network can be up to 120 C and the operating pressure can be up to 16 bar Thismayresultinariskofscaldingfromtouchingthesubstationand fromoutflowofthemedium Exceedingt...

Page 10: ...tructions if necessary 3 NB Tighten all pipe connections as they may have loosened during transport and handling 4 On systems that feature a safety valve establish a drain con nection in compliance wi...

Page 11: ...Before filling the system with water retighten all the pipe connec tions because vibrations and shocks during transport and handling may have caused leaks Once the system has been filled with water ti...

Page 12: ...he right Alwaysmountthesensoronthecoldestsideofthebuilding normally the north side It must not be exposed to morning sunlight and must not be po sitioned above windows doors ventilation ducts balconie...

Page 13: ...ion pump outside the substation is stopped for a protracted period we recommend shutting off the by pass thermostat for the same period NB Please note that substations fitted with Danfoss AVE expansio...

Page 14: ...Danfoss FJVR bypass thermostat Fig 2 so that when water is tapped the water heater immediately starts to produce hot water We re commend setting of the thermostat in pos 3 If you have to wait a long t...

Page 15: ...oss FJVRbypassthermostat Fig 2 sothatwhenwateristapped thewater heaterimmediatelystartstoproducehotwater Werecommendsetting ofthethermostatinpos 3 Ifyouhavetowaitalongtime i e morethan 20 sec for hot...

Page 16: ...time i e more than 20 sec for hot water it may be necessary to position the thermostat higher than pos 3 If you want to avoid waiting time altogether you will need to set up domestic hot water recirc...

Page 17: ...mmediatelystartstoproducehotwater Werecommendsetting the thermostat to pos 3 If you have to wait a long time i e more than 20 sec for the hot water it may be necessary to set the thermostat to a posit...

Page 18: ...ating conditions Indicative supply temperatures 40 C when the outdoor temperature is 10 C 55 C when the outdoor temperature is 0 C 65 C when the outdoor temperature is 10 C It is important to set the...

Page 19: ...power consumption For floor heating systems and old radiator set ups with large pipes and radiators turn the red switch to the right constant curve and set it to Max pos initially Then reduce the pre...

Page 20: ...build up in plate heat ex changers for domestic hot water on account of the large temperature fluctuations and because aerated water is used on the secondary side If it becomes necessary to clean the...

Page 21: ...the pipe connections Check that the safety valve on the cold water supply is functioning correctly Check the functionality by turning the lever on the safety valve Check that all components are intact...

Page 22: ...g Automatic components controller incorrectly adjusted or defective or possibly a power outage The pump is not working The pump is set at a step that is too low not all system types Air pockets in the...

Page 23: ...ivery Check whether the pump is running and whether there is a power supply to the pump Make sure that there is no air in the pump housing No hot water Dirt strainer in the district heating sup ply li...

Page 24: ...y EN 61000 6 2 2005 Electromagnetic compatibility Generic standard Immunity industry EN 61000 6 3 2007 Electromagnetic compatibility Generic standard Emission for residential commercial and light indu...

Page 25: ...gulations and the applicable legislation in every respect Installation and commissioning must only be performed by trained authorised personnel The substation is checked in the factory for leaks befor...

Page 26: ...26 DKDHR VI GP U2 02 Danfoss District Energy...

Page 27: ...27 27 Danfoss District Energy VI GP U2 02 DKDHR...

Page 28: ...Produced by Danfoss Redan A S 06 2012 VI GP U2 02 Danfoss Redan A S District Energy Omega 7 S ften DK 8382 Hinnerup Tel 45 87 43 89 43 Fax 45 87 43 89 44 redan danfoss com www redan danfoss dk...

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