Wilo Control SC-Booster Notice De Montage Et De Mise En Service page 80

If no peak-load pump is active any longer, the
base-load pump switches off when the deactiva -
tion threshold is exceeded (
after the delay time has expired (menu 1.2.5.1),
if necessary following a zero-flow test.
Delay times can be set in the menus 1.2.5.2 and
1.2.5.3 for activation and deactivation of the
peak-load pump.
If the frequency converter has a fault, the switch -
gear behaves like switchgear without a frequency
converter (see next section).
Normal operation of SC switchgear without
frequency converter (see Fig. 3)
An electronic pressure transmitter (measurement
range to be set in menu 5.2.1.0) supplies the con -
trol variable actual value as a 4...20 mA current
signal. There is no option for load-sensitive speed
adaptation of the base-load pump, as a result of
which the system works as a two-point controller
and keeps the pressure in the range between the
activation and deactivation thresholds (menus
1.2.2.1 to 1.2.2.8). These must be set in relation to
the reference setpoint (menu 1.2.1.1).
If there is no "Ext. Off" signal, no fault and the
drives are activated (menu 3.1.0.0), the base-load
pump starts when its activation threshold is
œ
undershot . If the power requirement cannot be
met by this pump, the control system switches on
a peak-load pump and, if the requirement
increases further, other peak-load pumps (activa -
Ÿ
tion threshold:
pump; menus 1.2.2.3/5/7).
If the requirement drops until no peak-load pump
is required any longer in order to meet the require -
ment, then the peak-load pump switches off
(deactivation threshold:
for each pump; menus 1.2.2.4/6/8).
If no peak-load pump is active any longer, the
base-load pump switches off when the deactiva -
tion threshold is exceeded (
after the delay time has expired (menu 1.2.5.1).
Delay times can be set in the menus 1.2.5.2 and
1.2.5.3 for activation and deactivation of the
peak-load pump.
Installation and operating instructions Wilo-Control SC-Booster (SC, SC-FC, SCe)
ž
menu 1.2.2.2) and
; can be individually set for each
¡
; can be individually set
ž
menu 1.2.2.2) and
Normal operation of SCe switchgears in the
p-c control mode (see Fig. 4)
The p-c control mode can be selected in both the
"SCe AVC" and "SCe NWB" devices.
The "Vario" base-load pump is described below
(see menu 1.1.2.0).
An electronic pressure transmitter (measurement
range to be set in menu 5.2.1.0) supplies the con -
trol variable actual value as a 4...20 mA current
signal. Then the controller maintains the system
pressure at a constant level by means of the com -
parison of the setpoint/actual value (for setting of
›
the reference setpoint see menu 1.2.1.1).
If there is no "Ext. Off" signal, no fault and the
drives are activated (menu 3.1.0.0), the base-load
pump with load-sensitive speed control (Fig. 4a)
starts when its activation threshold is undershot
œ
(menu 1.2.2.1). If the performance requirement
can no longer be met by this pump at the speed
that can be set in menu 1.2.3.1, another pump
starts when the reference setpoint is undershot
›
and takes over the speed control (Fig. 4b).
The previous base-load pump continues to run at
max. speed as a peak-load pump. This procedure
is repeated as the load increases until the
maximum number of pumps is reached (here:
3 pumps – see Fig. 4c).
If the requirement drops, then the controlling
pump is switched off when the speed that can be
set in menu 1.2.3.2 is reached and the reference
setpoint is exceeded at the same time; then, a for -
mer peak-load pump takes over control.
If no peak-load pump is active any longer, the
base-load pump switches off when the deactiva -
ž
tion threshold is exceeded (
after the delay time has expired (menu 1.2.5.1),
if necessary following a zero-flow test.
Delay times can be set in the menus 1.2.5.2 and
1.2.5.3 for activation and deactivation of the
peak-load pump.
The "cascade" base-load pump mode (see
menu 1.1.2.0) corresponds to the description
of the normal operation of SC switchgears with
a frequency converter (FC).
Normal operation of "SCe NWB" switchgears in
the p-v control mode (see Fig. 5 – 7)
An electronic pressure transmitter (measurement
range to be set in menu 5.2.1.0) supplies the con -
trol variable actual value as a 4...20 mA current
signal. Then the controller maintains the system
pressure at a constant level by means of the com -
parison of the setpoint/actual value.
The setpoint is dependent on the current volume
flow (Fig. 5) and is between the setpoint at zero
œ
flow – see menu 1.2.1.4 – and the reference
›
setpoint – see menu 1.2.1.1 – when the vol -
ume flow of the unit is at a maximum (without
ž
standby pump) – see menu 1.2.1.3.
English
menu 1.2.2.2) and
9