Siemens Building Technologies
Basic Documentation RVL470
CE1P2522E / 30.03.2000
Landis & Staefa Division
Function block "Service functions and general settings"
47/68
With plant types using a boiler, the switching differential corresponds to the set switch-
ing differential (± 0.5
*
SD), and with plant types using a mixing valve, to the neutral
zone (±1 °C).
The display shows the fault status message as ERROR. More detailed information is
given on operating line 50 under error code 120.
The flow alarm can be deactivated by entering --:--.
ERROR
t
T
V
w
x
25
24D
0
5
t
A
t
A
t
A
t
1
t
2
y
t
Time
T
V
Flow temperature
t
1
Start of ERROR display
w
Setpoint
t
2
End of ERROR display
x
Actual value
t
A
Waiting time (set on operating line 171)
y
Setpoint band
•
At t
1
, a fault status message is triggered; during the period of time t
A
(set on operating
line 171), the actual value stayed below the setpoint band y
•
At t
2
, the fault status message is reset; the actual value x has reached the setpoint
band y
13.4.3. Manual overriding of operating mode (contact H1)
Using a simple remote operation facility , the controller's operating mode can be over-
ridden. This is accomplished by bridging terminals H1–M.
It is possible to select the operating mode that shall apply when H1–M are bridged:
Setting
Operating mode
0
Standby
1
AUTO
2
REDUCED
3
NORMAL
As long as this function is activated, the LED of the respective operating mode button
flashes at low frequency (approx. 0.5 Hz). The buttons themselves are however inoper-
able.
Once this function is deactivated, the RVL470 will resume the operating mode previ-
ously selected.
Contact H1 has priority over contact H2 (refer to the section below). If both contacts are
activated (closed), contact H2 is inactive. With plant types 4, 5 and 6, contact H1 is in-
active.
13.4.4. Pump overrun
To prevent heat from building up, a common pump overrun time can be set for all
pumps associated with the controller (with the exception of the circulating pump) on op-
erating line 174. In that case, the pumps overrun maintains the charging position for the
set period of time.
In interconnected plants, the time set also affects the forced signals that a boiler can
deliver to ensure overtemperature protection.
For detailed information, refer to section "10.4.5. Protection against boiler overtem-
peratures".
