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Building Technologies
Modular Heating Controller RMH760B
CE1P3133en
HVAC Products
6 Boiler temperature control
05.02.2007
If the control system’s response is too prompt so that significant overshoot or even
permanent oscillations occur, setting parameters Xp, Tn and Tv must be increased in
steps. A new readjustment should be made only after the control action resulting from
the previous readjustment is completed.
t
TBo
TBoSetpt
31
32
D
11
1. Reduce Xp in steps of about 25 % of the previous value.
2. Increase Tv in steps of 2 to 5 seconds.
If this is not sufficient:
3.
Increase Tn in steps of 10 to 20 seconds.
6.5.5
External boiler temperature control
The RMH760B delivers a DC 0…10 V signal as the boiler temperature setpoint for an
external boiler temperature controller.
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Boiler > Setp compensation boiler
Operating line
Range
Factory setting
Setpoint at 0 Volt
–150…50 °C
0 °C
Setpoint at 10 Volt
50…500 °C
100 °C
Limit value
0…140 °C
10 °C
Using setting parameters, the DC 0…10 V output can be matched to the receiver’s
input. In the case of setpoints below the limit value, the output indicates DC 0 V.
6.6
Protective boiler functions
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Boiler > Limitations
Operating line
Range
Factory setting
Boiler temperature max
25…140 °C
95 °C
Boiler temperature min
8…140 °C
10 °C
Optimization min boiler temp
On / Off
On
Boiler return temperature min
---- / 8…140 °C
---- °C
Bypass pump switching diff
1…20 K
6 K
Lock sig maintained boil ret temp
None / Uncritical / Critical Critical
Frost prot (release input off)
0…60 min
6 min
Frost prot (release input Off)
On / Off
On
Frost prot (release input off)
On / Off
Off
Protective boiler startup
On / Off
On
Protective boiler startup
Pump on / Pump off
Pump on
Delta boiler temp max (stage 2)
0…10 K
1 K
Control action is
too fast
Setpoint compensation
Settings
