Akva Lux TDP-F District heating flat station for direct heating and domestic hot water systems Akva Lux TDP-F Table of contents Akva Lux TDP-F... 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... 4 Maintenance... 7 Troubleshooting DHW... 8 Troubleshooting HE... 9 DH-SMT/PL VI.KR.O1.02 Danfoss 09/2006 1
Safety notes Following instructions refer to the standard design of the Akva Lux TDP-F 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 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. We recommend installation of 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. Noise level 55 db Corrosion protection All pipes and components are made of stainless steel and brass. The maximum chloride compounds of the medium should not exceed 300 mg/l. The risk of equipment corrosion increases considerably if the recommended permissible chloride compounds are exceeded. Delivery The Akva Lux TDP-F flat station is delivered without cover as a standard. Optional flat station equipment: - TVM-W mixing valve - thermostatic by-pass, - connection pipe for circulation, - circulation pump, - safety valve / non-return valve, - return temperature limiter, - ball valves w. and w/o pocket for pressure/ thermometer gauge 3/4 ext. thread - ball valves w and w/o pocket for pressure/ thermometer gauge 3/4 int. thread - thermometer Ø35 - zone valve with actuator - connection rail with 7 connections 3/4 (int. thread), insulated or non-insulated, - room thermostat with day and /or week program, - heat meter (DH supply), - cold water meter - 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 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). 2 VI.KR.O1.02 Danfoss 09/2006 DH-SMT/PL
Mounting 1 2 1 2 3 3 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 Lux TDP-F 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 Lux TDP-F 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 T-piece on the top part of the plate heat exchanger, remove blind plate and mount connection pipe for circulation (optional feature). - Remove conical screw (2) (4 mm) on the T-piece above the PT C controller. - Loosen and move capillary tube with union nut from pos 3. to pos. 2. - Screw the conical screw from pos 2 (4 mm) on to the muff at pos. 3. - Connect DHW circulation system with connection pipe for circulation. - Remember pump assembly and non-return valve mounting in the DHW circulation 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 The flat station is equipped with a fitting piece for insertion of DCW meter. Assembly of DCW meter Please refer to above assembly instructions for heat meter. Zone valve with actuator The flat station is equipped with a fitting piece for insertion of zone-valve with actuator Assembly of zone valve with actuator Please refer to above assembly instructions for heat meter Return temperature limiter The flat station is equipped with a fitting piece for insertion of return temperature limiter. Assembly of return temperature limiter Please refer to above assembly instructions for heat meter. DH-SMT/PL VI.KR.O1.02 Danfoss 09/2006 3
Pipes connections Internal installation and district heating* pipes connections must be made by means of threaded or welded connections. Connections: 1 District heating (DH) supply 2 District heating (DH) return 3 Domestic cold water (DCW) inlet 4 Domestic cold water (DCW) outlet 5 Domestic hot water (DHW) 6 Heating (HE) supply 7 Heating (HE) return 8 DHW circulation - optional Connection sizes: DH + DCW + DHW: HE + optional DHW circ.: G ¾ (int. thread) G ¾ (int. thread) Dimensions (mm): Without cover: H 640 x W 565 x D 110 (incl. ball valves) H 520 x W 565 x D 110 (excl. ball valves) With cover: H 740 x W 600 x D 150 * 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 Lux TDP-F 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 unproblematically, it can be taken into a continuous use. All Danfoss heat exchangers and flat stations have been pressure tested prior to delivery. 4 VI.KR.O1.02 Danfoss 09/2006 DH-SMT/PL
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 temperature in the house is controlled by radiator thermostats. As an option the Akva Lux TDP-F 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 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. 3. Limiting flow controller (DH return) Optional substation equipment, which is mounted on district heating company request. Limiting flow controller should be set to the required maximum return temperature, in compliance with the local demands. Approximate thermostat scale setting: I = 10 C 1 = 20 C 2 = 30 C 3 = 40 C 4 = 45 C I = 50 C (max. temp.) To ensure sufficient cooling and proper operation the HE return temperature (thermometer indication on secondary return) must be lower than the temperature set on the flow controller. DH-SMT/PL VI.KR.O1.02 Danfoss 09/2006 5
4. DHW temperature control The DHW temperature is controlled by a combined hydraulic and thermostatic valve the PT C controller. The DHW temperature control is made by turning the controller head to a higher (warmer) or lower numerical value (colder). The temperature should be set to 45-48 C at normal use (8-10 l/ min). The temperature should never exceed 55 C to avoid lime scale precipitation in the heat exchanger. PT C controller Approximate PT C controller settings: 1 = 25 C 4 = 55 C 2 = 35 C 5 = 65 C 3 = 45 C 6 = 75 C Setting changes: Set the temperature by turning the controller head. 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 Lux TDP-F flat station is connected to the DHW 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 Lux TDP-F flat station has been delivered with by-pass control and this must be changed to DHW circulation control, 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.) 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. 6 VI.KR.O1.02 Danfoss 09/2006 DH-SMT/PL
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 the 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. DH-SMT/PL VI.KR.O1.02 Danfoss 09/2006 7
Troubleshooting DHW Problem Possible cause Solution In general: Does the PT C controller work incorrectly? In general: Are the operating conditions satisfactory? PT C controller leaking. DHW tap load too low. If the quantity of tap water is normal (temperature unimportant), it indicates that the PT C controller works correctly. 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 Lux TDP-F. One of the two O-rings is defective (does not influence the PT C operating). 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 DHW heat exchanger. The diaphragm of the PT C controller is defective. PT C controller wrongly adjusted. Strainer in primary flow clogged. Locate defect in another part of the installation. Contact district heating supplier. Replace PT C controller (use new sealing). Replace diaphragm or PT C controller. See PT C controller instructions. Clean strainer. DHW tap load too low; Tap temperature too low; Tap temperature fluctuates. DHW temperature too high System with DHW circulation: DHW temperature falls shortly after tapping has started. DH return water temperature too high while on standby. The plate heat exchanger is cold. DH return water temperature too high while on standby. The plate heat exchanger is hot. DH return temperature too high during hot water tapping (poor cooling). Defective non-return valve in thermostatic battery (check if DHW tap temperature is lower than DHW from flat station, or close ball valve on DCW inlet for flat station). Defective non-return valve in DHW circulation (DHW circulation return pipe is getting cold during tapping of hot water). Lime scale precipitation in DHW plate heat exchanger ( t of DH flow too low during DHW tapping). Dirt in PT C controller. PT C controller wrongly adjusted Thermostatic element in PT C controller defective Bypass thermostat is defective or wrongly adjusted. Bypass thermostat is defective or wrongly adjusted. Dirt (sand, iron splinter or similar) in PT C controller. Controller does not close after tapping. Noise from flow can often be heard. The DHW temperature is set too high and/or lime scale precipitation in the DHW plate heat exchanger. Clean or replace non-return valve. Clean or replace non-return valve. Replace plate heat exchanger. Cleaning, see PT C controller instructions See PT C controller instructions Replace PT C controller Replace or adjust bypass thermostat correctly. Replace or adjust bypass thermostat correctly. Disassemble the controller for cleaning. See PT C controller instructions. Set PT C controller in correct position (see PT C controller instructions) and/or replace the plate heat exchanger. 8 VI.KR.O1.02 Danfoss 09/2006 DH-SMT/PL
Troubleshooting HE If operating disturbances occur, the following basic features should be checked before carrying out actual troubleshooting: - 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 Strainer clogged on DH or HE side (radiator circuit). Clean gate/strainer. No heat Uneven heat distribution Supply temperature too low Poor cooling Filter 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. Air pockets in the system. Strainer clogged. 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. Clean the filter (after consulting the district heating plant). Check the functioning of the differential pressure controller clean the valve seat if required. Check the functioning of the room thermostat/actuator - clean the zone valve seat if required. Air the installation thoroughly. Air the installation thoroughly Clean gate/strainer. 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 flow temperature to the radiators as low as ever possible, while maintaining a reasonable level of comfort. DH-SMT/PL VI.KR.O1.02 Danfoss 09/2006 9
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 10 VI.KR.O1.02 Danfoss 09/2006 DH-SMT/PL