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Building Technologies
Modular Heating Controller RMH760B
CE1P3133en
HVAC Products
9 Heating circuit control
05.02.2007
Δ
TFlSetpt
t
t
313
3D
01
TFlSetpt
TFlSetpt
Maximum increase:
Δ
t
t
Time
Δ
t
Unit of time
TflSetpt Flow
temperature
setpoint
Δ
TflSetpt Rate of setpoint increase per unit of time
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Heating circuit 1
(or
2
or
3
)
> Limitations
Operating line
Range
Factory setting
Flow temperature max
0…140 °C
80 °C
Flow temperature min
---- / 0…140 °C
----
Flow temperature rise max
---- / 1…600 K/h
----
Frost protection for the plant
Off / On
On
9.8.5
Pulse limitation
Every heating circuit is capable of handling pulses for limiting the load and the volumet-
ric flow. Prerequisite for the limitation of pulses is a heating circuit plant type with mixing
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 > Heating circuit 1
(or
2
or
3
)
> Limitations > Pulse limitation
Operating line
Range
Factory setting
Meter input
--- / 1…4
---
Type of limitation
Absolute / Scaled
Absolute
Limit value
5…4000 pulse/min
75 pulse/min
Integral action time Tn
0…255 min
60 min
The meter input is an input of function block ”Meter“ used for the limitation of pulses.
Only inputs configured to a terminal can be selected.
There are 2 types of limitation to choose from:
•
Absolute: Limitation takes effect when the limit value is crossed
•
Scaled: The limit value is fixed at 75 pulses/min. It can be adjusted but without
having any effect. If less than 5 pulses/min are received, fault status message
No
signal meter 1
(or
…
2
) will be delivered after 20 seconds. Heat meters with a scaled
output deliver 120 pulses/min if there is no supply of heat or no volumetric flow. Used
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 when the limitation is absolute. With the scaled limitation, the
Settings
Meter inputs
Settings
Meter input
Type of limitation
Limit value