E93.1001EN.C Manual CD
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When cascade connection is programmed correctly the water heater display will show the following.
Explanation "Cascade communication indicator"
NO CASCADE COMMUNICATION
> > >
no.1
Always showing the fixed ">>>"
CORRECT CASCADE COMMUNICATION
>
>
no.1
no.2
>
Showing alternating no.1 & no.2 with 1 second interval.
M
ONITOR SCREENS
To obtain cascade information, see § 10.4 on page 60.
O
UTPUT CONTROL AND WATER HEATER SEQUENCE
The total cascade set-up will act as one single big water heater, switching on- and off water heaters, depending
on the total load necessary to adjust and keep the flow temperature at the calculated value.
When the heat demand rises, more water heaters are switched on, and when heat demand falls, one or more
water heaters will be switched off. The water heater that was switched on last, will be switched off first, see table
below.
To distribute operating hours equally over all water heaters, the working sequence of the water heaters will change
every two hours.
Hour
Switching ON sequence
Switching OFF sequence
X
Master – Slave 1 – Slave 2 – Slave 3 –
Slave 4 – Slave 5 – Slave 6 – Slave 7
Slave 7 – Slave 6 – Slave 5 – Slave 4 –
Slave 3 – Slave 2 – Slave 1 – Master
X+2
Slave 7 – Master – Slave 1 – Slave 2 –
Slave 3 – Slave 4 – Slave 5 – Slave 6
Slave 6 – Slave 5 – Slave 4 – Slave 3 –
Slave 2 – Slave 1 – Master – Slave 7
X+4
Slave 6 – Slave 7 – Master – Slave 1 –
Slave 2 – Slave 3 – Slave 4 – Slave 5
Slave 5 – Slave 4 – Slave 3 – Slave 2 –
Slave 1 – Master – Slave 7 – Slave 6
X+6
Slave 5 – Slave 6 – Slave 7 – Master –
Slave 1 – Slave 2 – Slave 3 – Slave 4
Slave 4 – Slave 3 – Slave 2 – Slave 1 –
Master – Slave 7 – Slave 6 – Slave 5
………..
………………………………………………… …………………………………………………
Table: water heater sequence example of an eight water heater cascade.
In this table a total of eight water heaters (one master, seven slaves) is mentioned as an example, in practice the
maximum number in a cascade, without extra (external) control, is twelve water heaters.
