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Building Technologies
Boiler sequence controller RMK770
CE1P3132en
HVAC Products
6 Boiler sequence management
23.04.2009
If required, a boiler can be locked depending on the outside temperature.
Main menu > Commissioning > Settings > …
or
Main menu > Settings >
Boiler … > Operation settings
Operating line
Range
Factory setting
Boiler lock outside temp >
---- / 5…30 °C
---- °C
Boiler lock outside temp <
---- / –50…10 °C
---- °C
If the outside temperature exceeds the limit value or drops below it (refer to section 7.5
“Releasing and locking a boiler”), the respective boiler is locked or released again with
low priority only (see below under ”Priorities”).
The boiler sequence manager keeps faulty boilers released. As long as the fault is
pending, function block “Boiler“ keeps the boiler switched off. When the fault is rectified,
the boiler is put back into operation. The boiler sequence manager then decides if and
which boiler will have to be switched off.
As a result of the evaluation of the different settings and functions, the boilers are
assigned different priorities for the switch-on sequence.
•
Priority 1 is always assigned to the fixed lead boiler (with no restriction)
•
Priority 2 is assigned to all the other boilers (with no restriction)
•
Priority 3 is assigned to the backup boilers
•
Priority 4 is assigned to the boilers with locking by the outside temperature
•
Priority 5 is assigned to the boilers with (conditional) manual locking (release input)
•
Priority 6 is assigned to the boilers with (unconditional) manual locking (release
input)
The boiler released first is always the boiler with the highest priority. If several boilers
have the same priority, they are released according to their order of changeover.
Then, the procedure is repeated with the next higher priority.
Main menu > Boiler sequence manager > Boiler sequence order
Operating line
Adjustable values / remarks
Address number lead boiler
1
Address number 1st lag boiler
2
Address number 2nd lag boiler
3
The
Boiler order
menu shows the boiler order currently used.
6.3.3
Boiler sequence order
Normally, as the demand for heat increases, another boiler is switched on, whereby
only the first burner stage (x.1) is released first, followed by the second stage (x.2) or
modulation. Also refer to subsection 6.3.6 “Switching boilers on and off”.
Output stage
1 2
3
4
5
Boiler release
1.1 1.1+1.2 1.1+1.2+2.1 1.1+1.2+2.1+2.2 1.1+1.2+2.1+2.2+3.1
Locking of boiler
depending on the
outside temperature
Boiler fault
Priorities
Diagnostic choice
boiler order
Standard
