This function is available from REG and RegConfig firmware version 4.32 onward within the ELETTRA/SOLAR page of RegConfig.
The function selectable from the System Type drop-down menu is number 5 (FLACS) and allows you to manage up to 8 Instant Domestic Hot Water Producers in cascade using dry contacts and a flow meter.PHOTO TBD
...
In order to use this function, it is necessary to install, besides the Instant DHW Producers:
...
Water flow sensor and water Outlet Temperature that are both detected by the Grundfos VFS meter via the REG2VFS interface (for installation and configuration see the REG2VFS data sheet)
DHW Producers Number: indicate the number of producers installed
P07 Minimum Active generator number: indicated the minimum number of valves that are always left open and consequently the minimum number of generators that will be switched on as soon as the flow rate detected will be greater than zero. Setting this value > 1 could be useful in the case of large system where the activation of only 1 producer on departure could lengthen response time.
P08 Maximum Active generator number: indicated the maximum number of generators that can be activated simultaneously. If 5 generators are enabled, but the maximum number is 3, this means that at most the algorithm can switch on 3 generators even though 4 would be needed. This choice could be useful in the case you have calculated, for example, 3 producers are sufficient, but you have decided to install more to have redundancy and therefore give reliability to the system.
P09 Excluded generators: if maintenance is being carried out on a producer or a producer is faulty and awaiting repair, it can be excluded from the cascade by simply flagging the relative box. This function of excluding generators could also be useful in the case of diagnostic or ignition, if only 1 specific producer is to be switched on at a time.
...
P01 New generator threshold [l/min]: this is the threshold above which the next valve is opened. Therefore, if the threshold is 15 l/min, up to this flow rate value only one valve will be opened, above 15 l/min at least for time P03, a second valve will be opened, above 30 l/min (for P03 time) a third valve will be opened and so on.
P02 Hysteresis shut off generator [l/min]: if the flow rate, instead of increasing decreases, the valves will be shut down. This parameter allows a hysteresis to be considered as to have as little pendulum as possible. Let's take the example from the previous point assuming P02 is 3 l/min: if flow rate drops below 30-3 l/min for time P04, valve number 1 (the one that was open at the start of the cycle) will be shut down. When flow rate drops below 15 - 3 l/min for time P04 then the second valve will also be closed. When the flow rate goes to zero, the last producer still running will stop, but its valve will remain open.
P03 New generator counter [s]: this is the time for which the flow rate must remain over the threshold before one more valve is opened
P04 Shut off generator counter [s]: this is the time for which the rate flow must remain below the threshold minus hysteresis value before a valve is closed.
...
A diagram is shown to better explain parameters P01, P02, P03, and P04; in red the flow rate trend over time, in blue the thresholds (multiples of P01) and in yellow the hysteresis referring to each threshold (always equal to P02):PHOTO TBD
...
Instant DHW Producers cascade status and output setting
To the right of the set parameters, it is possible to visualize the status of the system status:
· Active generators number: is the number of producers whose valve is open;
· First active generator: is the number of the producer whose valve is open first, in the image below it is the sixth producer;
· Current flow rate and Current temperature: are the values read by the VFS in l/min and °C respectively;
· Generator activation Threshold [l/min]: shows the threshold value that must be exceeded for another producer to be added. This value depends on how many generators are already active. Assuming that P01 is 15 l/min: if only a producer is active, the threshold will be 15 l/min, if 2 producers are active the threshold will be 30 l/min etc.
· Generator deactivation Threshold [l/min]: shows the threshold value that must be exceeded (downwards) before removing a producer. This value depends on how many generators are active: if 3 generators are active, the threshold will be 27 l/min [P01*(number of active producer - 1) - P02], if 2 generators are active the threshold will be 12 l/min [P01*(number of active producer - 1) - P02], etc. If only one producer is active, this value will be negative if P02 is greater than zero.
· Add/Removal Filter Timer [s]: reports the countdown (if started) of parameters P03 and P04;
· Active generators: indicate the generators whose valve is open.
Numero dei generatori attivi: è il numero dei produttori la cui valvola è aperta;
Primo generatore attivo: è il numero del produttore che ha la valvola aperta per primo, nell’immagine sotto riportata il sesto produttore;
Portata istantanea e temperatura corrente: sono i valori letti dal VFS in l/min e °C rispettivamente;
Soglia per aggiunta generatore [l/min]: riporta il valore della soglia che deve essere superata per l’aggiunta di un altro produttore. Questo valore dipende da quanti generatori sono già attivi. Ipotizzando che P01 sia 15 l/min si ha che se solo un produttore è attivo la soglia sarà 15 l/min, se sono attivi 2 produttori la soglia sarà 30 l/min ecc.
Soglia per rimozione generatore [l/min]: riporta il valore della soglia che deve essere superata (verso il basso) prima di togliere un produttore. Questo valore dipende da quanti generatori sono attivi: se sono attivi 3 produttori la soglia sarà 27 l/min [P01*(numero produttori attivi - 1) - P02], se sono attivi 2 produttori la soglia sarà 12 l/min [P01*(numero produttori attivi - 1) - P02], ecc. Nel caso sia attivo un solo produttore questo valore risulterà negativo se P02 è maggiore di zero.
Timer Filtro Aggiunta/Rimozione [s]: riportano il countdown (se iniziato) dei parametri P03 e P04;
Generatori attivi: vengono indicati i generatori la cui valvola è aperta.
PHOTO TBD
All’interno della pagina USCITEREGIN (oppure USCITE IOA / IOB nel caso in cui siano necessarie espansioni in quanto il sistema REG gestisce anche altri attuatori all’interno dell’impianto di riscaldamento/raffrescamento) è possibile impostare le uscite da assegnare alle 8 valvole dei produttori:
PHOTO TBD
Le uscite sono così configurate:
...
uscita 98 e 99 → valvola del produttore numero 1 e 2
...
uscita 102 e 103 → valvola del produttore numero 3 e 4
...
uscita 106 e 107 → valvola del produttore numero 5 e 6
...
Within the REGDIN OUTPUT page (or IOA / IOB OUTPUT in case expansions are needed as the REG system also manages other actuators within the heating/cooling system), it is possible to set the outputs to be assigned to the 8 DHW producers valves:
...
The outputs are configured as follows:
Output 98 and 99 → producer valve number 1 and 2
Output 102 and 103 → producer valve number 3 and 4
Output 106 and 107 → producer valve number 5 and 6
Output 110 and 111 → producer valve number 7 and 8