28
Boiler operating mode
To set the boiler operating mode:
1.
"Menu"
2.
"Cascade"
3.
"Op mode boiler"
4.
"Select boiler"
Fig. 36
5. Select the required operating mode.
0
No default output for boiler (boiler OFF)
h
Manually adjustable default output for boiler
(boiler ON)
Automatically calculated default output for boiler
The boiler is switched on or off depending on the
buffer charging status and on the set priorities.
6. Press
"OK"
to confirm
Boiler priority
Using the priorities function, you can select the order in
which the boilers are started.
A maximum of 4 boilers can be managed with the cas-
cade controller. Therefore, a priority of 1 to 4 can be
selected (priority 1 = highest; priority 4 = lowest).
Where boilers have equal priority, the boiler with the
lowest number of hours run is always started first
(hours run + hours run offset).
An adjustable hours run tolerance is also taken into
account: If two boilers have the same priority, the next
boiler to be used will be the one which is still "warm"
and still within the tolerance.
Example 1
Fig. 37
With this setting, boiler 1 is started first. Then boilers 2,
3 and 4 are started.
Example 2
All boilers can also be set to the same priority (e.g. pri-
ority 1).
With this setting, the boilers are started depending on
the number of hours run.
The boiler with the lowest number of hours run is star-
ted first. The hours run tolerance is also taken into
account.
Example 3
Mixing priorities.
Example: Boilers 1 and 4 have priority 1 and boilers 2
and 3 have priority 2.
With this setting, boilers 1 and 4 are started first. The
order depends on the number of hours run and the tol-
erance.
Then boilers 2 and 3 are started. The order is again
dependent on the number of hours run and the toler-
ance.
Boiler starting point
The boiler sequence control is dictated by the buffer
charging status. Based on the buffer charging status,
the starting points can be defined as follows:
1.
"Menu"
2.
"Cascade"
Cascade
Cascade
(cont.)
5778 774 GB
Summary of Contents for Vitotrol 350-C
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