Set Values For The Pressure Switch - Wilo FLA Série Notice De Montage Et De Mise En Service

Proceed as follows when setting the pressure
switch:
Pressure switch type FF4....(Fig. 3a)
• Open the pressure switch cover by unscrewing the
screw plug and remove the cover.
• Open the gate valve on the discharge side and one
tap.
• Set the switch-off pressure using the adjusting
screw (item 19 in Fig. 3). The pressure can be read
in bar on the dial (item 24 in Fig. 3). Factory setting
is as shown on the attached acceptance test cer-
tificate.
• Slowly close the tap.
• Monitor the deactivation point on the pressure
gauge and correct it if necessary by turning the
adjusting screw (item 19 in Fig. 3).
• Slowly open the tap.
• Set the switch-on pressure using the adjusting
screw (item 20 in Fig. 3). The pressure difference
can be read on the dial (item 25 in Fig. 3). (The fac-
tory setting for the pressure difference Δp
between deactivation and switch-on pressure is
about 1.0 bar.)
• Close the tap again.
• Replace the pressure switch cover and tighten the
screw plug.
• After setting the pressure switch, secure it against
unauthorised adjustment (e.g. sealing).
• The pressure switch of type FF4 is designed as a
single-pole changeover contact. The switch con-
tact is wired at the factory to open when the pres-
sure drops and close when the target pressure is
reached (the pump runs with the switch contact
open).

8.1.1 Set values for the pressure switch

H(Q0) ... zero-delivery head of the system
H(geo)... geodesic head difference between high-
est fire hose reels and FLA
Pressure switch (1)
ON OFF
DS1E DS1A
Setpoint H(Q0) – 0.5 bar
Table 5
For example: H(Q0) = 75 m (~7.5 bar)
Setpoint = 6 bar
H(geo) = 20 m (~2.0 bar)
Pressure switch (1)
DS1E DS1A
6.0 bar 7.0 bar
Installation and operating instructions Wilo-FLA
ON
DS1E
Setpoint
Table 4
Example:
DS1E
6.0 bar
Pressure switch (2)
ON OFF
DS2E DS2A
DS1E DS1A
Pressure switch (2)
DS2E DS2A
6.0 bar 7.0 bar
DS..A ... switch-off pressure of the relevant pres-
sure switch(..)
DS..E ... switch-on pressure of the relevant pres-
sure switch(..)
Setpoint... specified operating pressure of FLA
NOTE!
H(Q0) can be found in the enclosed test report for
the FLA.
FLA-1:
Switch-on pressure = setpoint
Switch-off pressure = H(Q0) – 0.5 bar
Pressure switch (1)
OFF
DS1A
H(Q0) – 0.5 bar
H(Q0) = 75 m (~7.5 bar)
Setpoint = 6 bar
H(geo) = 20 m (~2.0 bar)
Pressure switch (1)
DS1A
7.0 bar
FLA-2:
H(Q0) > DS1A ≥ DS2A > DS1E ≥ DS2E ≥ DS3A >
DS3E
NOTE!
The set value for pressure switch 3 ON depends on
the system's hydraulic ambient variables; how-
ever, it should be within the limit values "min" and
"max" in Table 5.
Pressure switch (3)
ON
DS3E
min.: H(geo) + 0.5 bar
max.: Setpoint – 0.5 bar
Pressure switch (3)
DS3E
2.5 ... 5.5 bar
English
OFF
DS3A
DS2E
DS3A
6.0 bar
37