Description And Function; Description Of The Product; Function Description; Set-Up Of The Control Device (Fig. 1) - Wilo SC-Booster SC Notice De Montage Et De Mise En Service

English

6 Description and function

6.1 Description of the product

6.1.1 Function description

The Smart control system, controlled by a micro-
controller, is used to control and regulate pressure
boosting systems with up to 4 individual pumps.
The pressure of a system is measured with corre-
sponding signal transmitters and controlled load-
sensitively.
In the SC-FC version, the controller acts on a fre-
quency converter, which in turn influences the
speed of the base-load pump. A modification of
the speed changes the volume flow and thus the
power output of the pressure boosting system.
Depending on load requirement, non-controlled
peak-load pumps are switched on or off automat-
ically.
In the SCe version, each pump has an (integrated)
frequency converter, with only the base-load
pump undertaking the speed control.
In the SC version, all pumps are fixed speed pumps
– the pressure control is a 2-point control.
Depending on load requirement, non-controlled
peak-load pumps are switched on or off automat-
ically.

6.1.2 Set-up of the control device (Fig. 1)

The set-up of the control device is dependent on
the performance of the pumps that are to be con-
nected, and the version (SC, SC-FC, SCe) (see:
Fig. 1a SCe; Fig. 1b SC direct starting; Fig. 1c SC
star-delta starting; Fig. 1d SC-FC direct starting
(in switchbox); Fig. 1e SC-FC direct starting
(in standing cabinet); Fig. 1f SC-FC star-delta
starting). It consists of the following main compo-
nents:
• Main switch: Switching the switchgear on/off
(item 1)
• Human-machine interface (HMI): LCD for display-
ing operating data (see menus), LEDs for display-
ing the operating status (operation/fault),
operating knob for menu selection and parameter
input. (Item 2).
• Base board: Board with microcontroller; version
corresponding to device configuration (SC/SC-FC
or SCe) (item 3)
• Fuse protection of drives and the frequency con-
verter: Fuse protection of the pump motors and
the frequency converter. In DOL version devices:
Motor protection switch. In the SCe version:
Circuit breaker to protect the pump mains power
cable (Item 4).
• Contactors/contactor combinations: Contactors
for switching on the pumps. In SD version devices
including the thermal actuators for excess current
protection (set value: 0.58 * IN) and the time relay
for star-delta switching (item 5)
• Frequency converter: Frequency converter for
load-sensitive speed control of the base-load
pump - only in the SC-FC version (item 6)
42
• Motor filter: Filter for ensuring a sinusoidal motor
voltage and for suppressing voltage peaks - only
in the SC-FC version (item 7)
• EMC filter: Filter for suppressing EMC interference
on mains side - only in the SC-FC version (item 8)

6.2 Function and operation

DANGER! Risk of fatal injury!
When working on the open switchgear, there is
a danger of electric shock from touching the live
components.
This work may only be carried out by qualified
personnel!
:
NOTE
After connecting the switchgear to the supply
voltage, as well as after every mains interruption,
the switchgear returns to that operating mode
which was set before the voltage interruption.

6.2.1 Operating modes of the switchgear

Normal operation of SC switchgear with fre-
quency converter (FC) (see Fig. 2)
An electronic signal 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 constant by means of the comparison of
the setpoint/actual value (for setting of the refer-
›
ence setpoint see menu 1.2.1.1). If there is no
"external off" signal and no fault, the base-load
pump with load-sensitive speed control starts
when its activation threshold is undershot
(menu 1.2.2.1). 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, another peak-load pump (acti-
Ÿ
vation threshold: ; individually adjustable per
pump; menu 1.2.2.3/5/7). The peak-load pumps
run at constant speed, the speed of the base-load
pump is regulated to the setpoint
If the requirement drops until the controlling
pump is working in its lower performance range
and no peak-load pump is required any longer
in order to meet the requirement then the peak-
load pump switches off (deactivation threshold:
¡
; individually adjustable per pump; menu
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 undershot (
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 frequency
converter (see next section).
œ
¢
in each case.
ž
menu 1.2.2.2) and
WILO SE 01/2013