Table of Contents
Advertisement
Fault list and actions
Description of fault
Short-circuit flow
Open-circuit flow
Measured value of flow not
plausible
Measured value of flow not
plausible
Short-circuit return
Open-circuit return
Measured value of return not
plausible
Maximum return temperature
exceeded
(S)LT cutout temperature
reached
Maximum temperature
gradient exceeded
Excessive ∆T
Return temperature above
flow temperature
Legend
Fault handling routines
Siemens Building Technologies
HVAC Products
Function
Operating state
Faulty
TkIst < 0 °C
TkIst > 124 °C
TkRuec < 0 °C
TkRuec > TSTB
TkIst > TSTB
Burner is switched off
∆TkIst > TempGradMax
Switch burner off
∆ϑ > dTkTrSTB
Reduce output by 20 %
∆ϑ > dTkTrSTB + 8K
Reduce output to min.
∆ϑ > dTkTrSTB + 16K
Burner off
TkRuec > TkIst +
(X)
Sd_RL groesser _VL
∆ϑ
TkIst - TkRuec
∆TkIst
Gradient of actual boiler temperature
If a fault occurs and the limit thermostat's (TW) cutout temperature is reached, the
accumulated heat must be carried away from the boiler by activating the fan or the
heating circuit pump (if not yet running).
Response if the cutout temperature is reached:
• Pump and fan overrun
In the event the above faults occur, following applies:
If the TW cutout temperature «TkMax» (parameter) is reached, the heating circuit pump
will be activated to accelerate the dissipation of heat and optional heating circuits will be
forced to draw off heat.
If the (S)LT's cutout temperature is reached, the fan will also be activated.
Both are active until the relevant trigger criterion is no longer present, the maximum time
being «ZGebNach» (parameter).
Basic Documentation LMU54... / LMU64...
3 Functions
Unfa-
vora-
Diagnosis /
ble
fault display
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Over-
X
temperature
Small heat
X
consumption
X
X
X
X
X
X
Actions
Lockout
Start
Immedi-
After
prevention
ately
(min.)
X
10
X
10
X
10
X
10
X
10
X
10
X
10
X
10
Already
activated
by TW
X
X
X
After number
of faults
(in 24 h)
Parameter:
GrenzeNach
erwaermung
Parameter:
GrenzeGradi
ent
Parameter:
GrenzeDelta
T
Parameter:
GrenzeRL_gr
oesserVL
41/171
CC1P7494en
07.11.2002
Advertisement
Table of Contents
