WEG SSW7000 Guia página 2

I. DESCRIPTION
The ground fault CT is used to measure the ground fault current of the three-phase circuit
of the motor supply. The ground fault protection using the current measurement is based on
the principle that the ground fault current must be close to 0 (zero) if the insulation of the
cables of connection to the motor and of the motor is in perfect conditions.
The level of actuation of the ground fault protection must be adjusted according to the
electrical installation used. The activation and adjustment of the ground fault using the
current measurement are performed by means of the parameters P0825, P0826 and P0828
of the SSW7000. Refer to the programming manual of the product to obtain details about
the programming of these parameters.
Figure 1 – Ground fault protection by measurement of leakage current.
II. INSTALLATION
The ground fault CT is installed on the same insulating base to which the CTs are fixed to
measure the currents on the motor phases, but on the back part of the support, as shown in
figures 1 and 2. This base features holes to fix the ground fault CT by using plastic clamps,
as shown in figure 2.
2
INSTALLATION GUIDE
GROUND FAULT CT – SSW7000
Figure 2: Installation of the ground fault CT.
1
1. Clamps to fix the
CT.