Siemens LMU54 Series - PID Controller Coefficients of Delta-T Supervision; Summary of All ∆T Parameters

67/171
Siemens Building Technologies Basic Documentation LMU54... / LMU64... CC1P7494en
HVAC Products 3 Functions 07.11.2002
This value is used in connection with the ∆T limitation for controlling the pump’s degree
of modulation. With the ∆T supervision, «dTkTrMax» is the setpoint for the control of the
measured temperature differential between flow and return.
«dTkTrMax» can be set independently of «dTkTrNenn» and can even be greater than
«dTkTrNenn». When setting «dTkTrMax», the permissible temperature differential of the
associated heat exchanger must be observed.
If required.
Proportional coefficient of ∆T supervision
Derivative action time of ∆T supervision
Integral action time of ∆T supervision
Mandatory settings
No. DPA no. Parameter name Function Setting level
OEM Installer
1 180 QmodDrehzStufen
Number of speeds of the
modulating pump
OEM Yes If required
2 146 QmodMin
Minimum degree of
modulation
OEM Yes If required
3 147 QmodMax
Maximum degree of
modulation
OEM Yes If required
4 177 FoerderMin Minimum pump head OEM Yes If required
5 176 FoerderMax Maximum pump head OEM Yes If required
6 435 Klambda1 Filter time constant OEM If required No
7 179 KtAbtastDt Factor for sampling time OEM If required No
KonfigRg7 Configuration byte
Bit 0
Heating circuit pump
0: Multispeed;
1: Modulating
Installer Yes No
Bit 1
∆T limitation
0: Inactive; 1: Active
Installer Yes No
Bit 2
∆T supervision
0: inactive; 1: active
Installer Yes No
Bit 3
Bit 4
Plant volume
1,0: medium
Installer No Yes
Bit 5
∆T in reduced operation.
0: inactive; 1: active
Installer Yes No
Bit 6 Not relevant Installer No No
8 182
Bit 7 Not relevant Installer No No
PID controller coefficients
of delta-T supervision
KpDt
TvDt
TnDt
Summary of all ∆T
parameters