Galvanic Isolation (Pelv); Pelv - Protective Extra Low Voltage - GE AF-600 FP Design Manual

2.10 Galvanic Isolation (PELV)

2.10.1 PELV - Protective Extra Low Voltage

PELV offers protection by way of extra low voltage. Protection against electric shock is ensured when the electrical supply is of the PELV type and the installation
is made as described in local/national regulations on PELV supplies.
All control terminals and relay terminals 01-03/04-06 comply with PELV (Protective Extra Low Voltage) (Does not apply to grounded Delta leg above 400 V).
Galvanic (ensured) isolation is obtained by fulfilling requirements for higher isolation and by providing the relevant creapage/clearance distances. These require-
ments are described in the EN 61800-5-1 standard.
The components that make up the electrical isolation, as described below, also comply with the requirements for higher isolation and the relevant test as described
in EN 61800-5-1.
The PELV galvanic isolation can be shown in six locations (see illustration):
In order to maintain PELV all connections made to the control terminals must be PELV, e.g. thermistor must be reinforced/double insulated.
1. Power supply (SMPS) incl. signal isolation of U
termediate current voltage.
2. Gate drive that runs the IGBTs (trigger transformers/opto-couplers).
3. Current transducers.
4. Opto-coupler, brake module.
5. Internal inrush, RFI, and temperature measurement circuits.
6. Custom relays.
The functional galvanic isolation (a and b on drawing) is for the 24 V back-up option and for the RS 485 standard bus interface.
Installation at high altitude:
380 - 480 V, unit size 1x, 2x and 3x: At altitudes above 2 km, please contact GE regarding PELV.
380 - 480V, unit size 4x, 5x and 6x: At altitudes above 3 km, please contact GE regarding PELV.
525 - 690 V: At altitudes above 2 km, please contact GE regarding PELV.
, indicating the in-
DC
Illustration 2.7: Galvanic isolation
AF-600 FP Design Guide
2
39