Siemens LMU64 Series - Setting the Fan Parameters During Startup and Shutdown

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Siemens Building Technologies Basic Documentation LMU54... / LMU64... CC1P7494en
HVAC Products 3 Functions 07.11.2002
To visualize the following description, also refer to the sequence diagram of the LMU…
and the following graph.
Parameter LMU...
Speed
[min
-1
]
Signal
PWM [%]
NoG_MAX
N_VL*
(N_VL_Delta)
N_VL_QAA*
NhzMax
LmodVL*
LmodVL_QAA*
PhzMax
N_Vor
(N_Vor_Delta)
LmodVor
(N_ZL_Delta)
N_Nachstell_Delta
N_ZL* LmodZL*
N_Nachstell_Delta
(N_ZL_Delta)
N_ZL_QAA*
LmodZL_QAA*
N_TL*
(N_TL_Delta)
N_TL_QAA*
NoG_Null
LmodTL*
LmodTL_QAA*
LmodNull
* Depending on parameter «FaEinstellFlags3»
MAX
MAX
MIN
Boiler
OFF
Boiler
Heating
Extra function «Speed readjustment»
(optional)
Speed limitation
KonfigRg5)
N_Nachstell Kon1
N_Nachstell_Lern
7494d31E
Fan control and speed parameters
First, set the speed limits while speed readjustment is switched off.
For that purpose, set the fan control parameters («LmodZL», «LmodVor», etc.) to the
values required from the combustion point of view (with the medium flueway and at
mains voltage).
Then, also determine the associated fan speeds from the fan characteristic and
parameterize them accordingly («N_ZL», «N_Vor», etc.).
In a first approach, set the limit values for the permitted bands very wide
(«N_ZL_Delta», «N_Vor_Delta», etc.).
The values of fan control and fan speed can now be optimized.
Speed limits
First, the speed readjustment should be set to the required or parameterized speed
readjustment.
When the optimization or setting is completed, proceed to the next step and determine
and set the speed limits.
For that purpose, use the PC tool and record the speed (Gebl_F_Drehz) in a startup and
shutdown cycle under the following boundary conditions:
1. With the minimum flueway and undervoltage (AC 195 V)
2. With the maximum flueway and overvoltage (AC 253 V)
Now, set the speed bands (speed limits about the selected speeds, that is, «N_ZLV +/-
N_ZL_Delta», etc.) such that in all possible worst cases, the measured speed lies within
the valid band (see above).
Faults outside these worst cases give rise to a violation of the speed limits and lead to
appropriate reactions (refer to sequence diagram).
Setting the fan parameters
during startup and shutdown