Grundfos CRNE - Additional Protection

PE
L2
L1
L3
TM082860
Model K
Pos. Description
L1 Phase 1
L2 Phase 2
L3 Phase 3
PE Protective earth
6.8 Additional protection
6.8.1 Residual-current circuit breakers
WARNING
Electric shock
Death or serious personal injury
‐ This product can cause a DC current in
the protective-earth conductor. If a
residual current-operated protective
(RCD) or monitoring (RCM) device is
used for protection in case of direct or
indirect contact, only an RCD or RCM
of Type B is allowed on the supply side
of this product.
The residual-current circuit breaker must be marked.
TM066230
Take into account the total leakage current of all the
electrical equipment in the installation.
This product may cause a direct current in the
protective-earth conductor.
Connection example for three-phase supply
The figure shows an example of a mains-connected
three-phase motor with a main switch, a backup fuse
and a residual-current circuit breaker, type B.
L1
L2
L3
L2
L1
L3
PE
1
TM069815
Pos.
Description
1 Residual-current circuit breaker, type B
L1 Phase 1
L2 Phase 2
L3 Phase 3
PE Protective earth
6.8.2 Overvoltage and undervoltage protection
Overvoltage and undervoltage may occur in case of
unstable power supply or a faulty installation. The
product stops if the voltage falls outside the
permissible voltage range. The product restarts
automatically when the voltage is within the
permissible voltage range. The product requires no
additional protection relay.
The product is protected against transients
from the power supply according to EN
61800-3. In areas with high lightning
intensity, we recommend external lightning
protection.
Overvoltage category:
The product is approved for Overvoltage category III
rating.
6.8.3
Overload protection
The motor-current protection settings are fixed for
each motor variants. The settings ensure that the
motor is protected against overtemperature in all
operating states with regard to supply voltage and
shaft load, including a blocked shaft.
The motors are current controlled and will respond by
reducing the speed if the shaft load increases more
than 10 % of the nominal load.
If the shaft load forces the speed down to minimum
speed, the motor shuts down.
A sudden increase in the motor current caused by a
fault where the peak of the motor current is increased
60 % above nominal will cause the motor to shut
down within 0.5 ms.
The product requires no additional protection.
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English (GB)