Motor Protection; Operation Of The Switchgear - Wilo SC-Booster SC Notice De Montage Et De Mise En Service

Fault-actuated switchover of multi-pump
system
SC switchgear with frequency converter (FC):
If the base-load pump has a fault, it is switched off
and another pump is switched onto the frequency
converter. If the frequency converter has a fault,
the switchgear works like an SC switchgear with-
out frequency converter.
SC switchgear without frequency converter:
If the base-load pump develops a fault, it is
switched off and one of the peak-load pumps is
managed by the control system as a base-load
pump.
SCe switchgear:
If the base-load pump develops a fault, it is
switched off and another pump takes over the
control function.
A fault on a peak-load pump always leads to it
being deactivated, and activation of another
peak-load pump (possible also the standby
pump).

6.2.2 Motor protection

Overtemperature protection
Motors with WSK (thermal winding contact) signal
a winding overtemperature to the switchgear by
opening a bimetal strip contact. The WSK is con-
nected according to the wiring diagram.
Faults on motors that are equipped with a tem-
perature-dependent resistor (PTC) for overtem-
perature protection can be registered using
optional evaluation relays.
Excess-current protection
Direct-starting motors are protected by motor
protection switches with thermal and electro-
magnetic trip triggers. The trigger current must
set directly on the motor protection switch.
Motors with Y-∆ starting are protected by thermal
overload relays. These are installed directly on the
motor contactors. The trigger current must be set
and is 0.58 * I
nom
All motor protection devices protect the motor
during operation with the frequency converter or
in mains operation. Pump faults which reach the
switchgear result in deactivation of the corre-
sponding pump and activation of the SSM. When
the cause of the fault has been rectified, it is nec-
essary to acknowledge the fault.
The motor protection is also active in manual
mode, and leads to deactivation of the corre-
sponding pump.
In the SCe version, the pump motors protect
themselves by mechanisms integrated in the fre-
quency converters. The error messages from the
frequency converters are handled in the switch-
gear as described above.
Installation and operating instructions Wilo-Control SC-Booster (SC, SC-FC, SCe)
with the Y-∆ starting used.

6.2.3 Operation of the switchgear

Operating elements
• Main switch on/off (lockable in "Off" position)
• The LCD shows the operating statuses of the
pumps, the controller and the frequency con-
verter. The menu selection and parameter input
are performed using the operating knob. Turn the
knob to change values or to scroll through a menu
level; press it in order to select and confirm:
Information appears on the display as shown in
the sample illustration below:
1
4
5
4
Fig. 5: Display structure
Item Description
1 Menu number
2 Value display
3 Units display
4 Standard symbols
5 Graphic symbols
English
4
2
3
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