Wilo Control SC-Booster, Инструкция по установке и эксплуатации

Страница: 79 / 1795

English
8 WILO SE 09/2018
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 pres
-
sure-boosting systems with up to 4 single pumps.
The pressure of a system is measured with corre
-
sponding pressure transmitters and controlled in a
load-sensitive way.
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
rated power of the pressure-boosting system.
Non-controlled peak-load pumps are switched on
and off automatically depending on the load
requirement.
In the SCe version, each pump has an (integrated)
frequency converter, while in the “SCe AVC” ver
-
sion, only the base-load pump undertakes the
speed control. If “SCe NWB” is in the p-v control
mode, all pumps are controlled and run at the
same speed unless a pump stops or starts.
In the SC version, all pumps are fixed speed
pumps – the pressure control is a 2-point control.
Non-controlled peak-load pumps are switched on
and off automatically depending on the load
requirement.
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 connected and the version (SC, SC-FC, SCe)
(see: Fig. 1a SCe; Fig. 1b SC direct start; Fig. 1c SC
star-delta start; Fig. 1d SC-FC direct start
(in design switchbox); Fig. 1e SC-FC direct start
(in free-standing cabinet); Fig. 1f SC-FC star-
delta start). It consists of the following main
components:
• Main switch: Switches 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 button for menu selection and parame
-
ter input (item 2)
• Base board: Printed circuit board with microcon
-
troller; version corresponding to device version
(SC/SC-FC or SCe) (item 3)
• Fuse protection for drives and frequency con
-
verter: Fuse protection for the pump motors and
the frequency converter. In DOL version devices:
Motor protection switch. In the SCe version: Cir
-
cuit breaker for the fuse for the pump mains sup
-
ply cable (item 4)
• Contactors/contactor combinations: Contactors
for switching on the pumps. In SD version devices,
including the thermal tripping devices for excess
current protection (default value: 0.58 * IN) and
the time relay for the star-delta switchover
(item 5)
• Frequency converter: Frequency converter for
load-sensitive speed control of the base-load
pump – only in the SC-FC version (item 6)
• Motor filter: Filter for ensuring a sinusoidal motor
voltage and for suppressing overvoltage – 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.
The work must only be carried out by qualified
personnel!
After connecting the switchgear to the supply
voltage, as well as after every mains interruption,
the switchgear returns to the operating mode set
before the power interruption.
6.2.1 Switchgear operating modes
Normal operation of SC switchgears with fre
-
quency converter (FC) (see Fig. 2)
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 starts
when its activation threshold is undershot
œ
(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, other peak-load pumps (activa
-
tion threshold:
Ÿ
; can be individually set for each
pump; menus 1.2.2.3/5/7). The peak-load pumps
run at constant speed, the speed of the base-load
pump is controlled to the setpoint
¢
in each case.
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:
¡
;
can be individually set for each pump;
menus 1.2.2.4/6/8).