107/238
Building Technologies
Modular Heating Controller RMH760B
CE1P3133en
HVAC Products
8 Main controller and primary controller
05.02.2007
This limitation too will be activated only when a valid value has been set. If the value is
invalid (entry of “----“), there will be no limitation.
This limitation is effective when the legionella function of a DHW circuit is active at the
primary controller. In that case, the 2 maximum limitations in space heating and DHW
heating mode will be deactivated.
Maximum limitation in DHW heating mode with the legionella function activated is
constant, that is, independent of the outside temperature. This limitation too will be
activated only when a valid value has been set. If the value is invalid (entry of “----“),
there will be no limitation.
8.8.4
Pulse limitation
Pulses for load or volume limitation can be fed to both the main controller and the
primary controller. Prerequisite for pulse limitation is a main or primary controller plant
type with mixing valve or other seat valve.
The pulses are delivered via the meter inputs of function block “Meter”. For more
detailed information about function block “Meter“, refer to chapter 11 “Function block
meter”. After one or several meter inputs have been configured, pulse limitation can be
set up.
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Main controller > Limitations > Pulse limitation
Main menu > Settings > Primary controller > Limitations > Pulse limitation
Operating line
Range
Factory setting
Meter input
---- / 1…4
----
Type of limitation
Absolute / Scaled
Absolute
Limit value
5…4000 pulses/min
75 pulses/min
Integral action time Tn
0…255 min
60 min
The meter input is an input of function block “Meter“ which is used for limiting the
number of pulses. All inputs selected must be configured to a terminal.
There are 2 types of limitation to choose from:
•
Absolute:
The limitation takes effect when the limit value is crossed
•
Scaled:
The limit value is fixed at 75 pulses/min. The limit value can be changed, but
with no effect.
If less than 5 pulses/min are received, fault status message
No pulse signal meter 1
(or
…2
,
…3
or
…4
) will be delivered after 20 seconds. Heat meters with a scaled output
send 120 pulses/min if there is no supply of heat or no volumetric flow. Together with
pulse limitation, this prevents hydraulic creep.
From the limit value, pulse limitation starts throttling the actuating device (mixing valve).
The setting is only active with absolute limitation. With scaled limitation, the limit value
can be set, but the function is performed with 75 pulses/min (fixed value).
The setting value determines the rate at which the flow temperature will be lowered:
•
Short integral action times lead to quick reductions
•
Long integral action times lead to slow reductions
Maximum limitation in
DHW heating mode with
legionella function
activated
Meter inputs
Settings
Meter input
Type of limitation
Limit value
Integral action time Tn
