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Building Technologies
Boiler Sequence Controller RMK770
CE1P3132en
HVAC Products
6 Boiler sequence management
23.04.2009
6.3.2
Orders for boilers to be switched on and off
As a general rule, the boilers are switched on in ascending order and switched off in
descending order:
1 – 2 – 3 – 4 – 5 – 6
However, various functions, settings and signals at the control inputs can impact this
order.
The boiler sequence selector is used to define the lead boiler and the switch-on se-
quence according to which the boilers are switched on.
Main menu > Boiler sequence manager > Boiler sequence optg mode
Operating line
Range
Factory setting
Boiler sequence selection, manually
Auto / 1…6
Auto
Auto
Automatic changeover of lead boiler after an adjustable period of time
1
Boiler sequence
1
–2–3–4–5–6
2
Boiler sequence
2
–3–4–5–6–1
3
Boiler sequence
3
–4–5–6–1–2
4
Boiler sequence
4
–5–6–1–2–3
5
Boiler sequence
5
–6–1–2–3–4
6
Boiler sequence
6
–1–2–3–4–5
The boiler sequence can also be preselected with an external selector. In that case, the
selection on the operator unit is deactivated.
1
2
3
4
5
6
Auto
Main menu > Commissioning > Extra configuration > Boiler sequence manager > Inputs
Operating line
Adjustable values / remarks
Boil sequence selection input 1
Assign terminal
Boil sequence selection input 2
Assign terminal
Boil sequence selection input 3
Assign terminal
The input’s operating mode can be parameterized for each terminal.
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Inputs > RMK770…
or
RMZ78…
Operating line
Range
Factory setting
Normal position
Open / Closed
Open
If the selection shall only be made between Auto and boiler 1, one binary input is
sufficient. With 2 binary inputs, the selection can be made between Auto – 1 – 2 – 3,
and with 3 binary inputs between Auto – 1 – 2 – 3 – 4 – 5 – 6.
The selector must be appropriately wired.
Boiler sequence
selector
Boiler sequence selection
on the operator unit
External boiler
sequence selector