Nimbus Pocket M NET R32 Installation Manual UK

Hydraulic connections 4.

Hydraulic connections 4. Hydraulic connections 4.4.1 Minimum water content a The system must be sized for a minimum water content of at least 5 litres for every kW of rated power. If the minimum water content is not observed, the appliance is not guaranteed to function. To optimise the system’s efficiency, comfort and correct operation, we recommend: – reducing the set-point temperature of the room during winter operation when the outdoor temperature increases. – increasing the set-point temperature of the room during summer operation when the outdoor temperature decreases. Should this not be possible, we recommend increasing the water content in the system. If, for an extended period of time, the minimum thermal load is lower than the minimum power delivered by the machine, we recommend increasing the water content in the system. 4.4.2 Expansion vessel The indoor unit is equipped with an expansion vessel. An external expansion vessel must be mounted on the system. i The installer is responsible fro ensuring that the expansion vessel is suitably sized in relation to the system’s total water content, regardless of the valves that can exclude certain parts of the hydraulic circuit. 4.4.3 Rated and minimum flow rate The minimum flow rate must always be guaranteed in all operating conditions. Model Nominal flow rate [l/h] Minimum flow rate [l/h] Flow meter ON threshold [l/h] NIMBUS EXT R32 35 M 600 430 390 NIMBUS EXT R32 50 M 860 430 390 NIMBUS EXT R32 80 M 1200 600 540 & M-T NIMBUS EXT R32 120 1550 770 702 M & M-T NIMBUS EXT R32 150 M & M-T 1900 940 852 4.4.4 Available pressure Make sure that the available pressure is not lower than the head loss of the entire hydraulic system. The curves in the pictures below shown the available pressure on the flow from the outdoor unit. NIMBUS EXT R32 KPa 90 80 70 60 50 40 30 20 10 1 0 0 500 1000 1500 2000 2500 3000 3500 Fig. l/h31 1 35 M - 50 M 2 80 M - 80 M-T 3 120 M - 120 M-T - 150 M - 150 M-T It is possible to install a supplementary circulator pump if the one supplied is not powerful enough. For the electrical connections, refer to the paragraph "Electrical connections". a If thermostatic or zones valves are installed on all terminals, mount a by-pass to guarantee the minimum operating flow rate. Consult the table in the paragraph “Rated and minimum flow rate”. 2 3 20 / EN

4.4.5 Characteristics of the supply water Make sure that the system is supplied with water having a hardness between 8°F and 15°F and conductivity below 500 μS/cm. In zones where the water is particularly hard, mount a water softener. Where the filling water is aggressive (the pH should be maintained between 7,5 and 9), ferruginous or hard, use treated water to prevent scale deposits, corrosion, and damage to the appliance. Even a slight amount of impurities in the water may lower the system’s performances. The filling water used must strictly be treated in the case of high-capacity installations (high volumes of water) or if frequent water top-ups are required to maintain a constant level of liquid in the system. If the system must be cleaned, fill it completely with treated water. Glycol adversely affects the appliance’s performances and we strongly advise not to use it. If glycol is nonetheless used, ARIS- TON shall not be held liable for any loss of efficiency of the system and recommends dosing it properly and performing maintenance. 4.4.6 Filling the system During filling, make sure that all the air is purged from the system. If the system’s pressure drops excessively, load water. a a To check the system water pressure, install a pressure gauge on the system as it is not present in the product. The system’s pressure can nonetheless be read through the system interface (parameter 1.16.7). The installation, initial start up, and configuration must be carried out in accordance with the instructions, by a qualified and competent installer only. The manufacturer declines all responsibility for damages caused to people, animals or possessions following incorrect installation of the appliance. a a i Hydraulic connections The accumulation of air can cause malfunctions to the system and damage the components. If frequent fillings (once a month or more frequently) are required for your system, this indicates a potential problem with the installation (leaks, expansion vessel problems). Contact your trusted installer to analyse and solve the problem quickly, and to prevent damage caused by corrosion of the components due to excessive water replacement in the system. We recommend using a dirt separator filter on the return circuit to protect the heat pump units, where supplied. 21 / EN