American Power Conversion SYMF800KH - Manual (Page 44)

Appendix: TT Systems
38 Symmetra MW 800 kW 3 × 400/230 V Installation - 990-1510D
When the protective device is an overcurrent protective device, it must be either:
• a device with inverse time characteristics and I a
must be the current causing automatic
operation within 5 seconds, or
• a device with an instantaneous tripping characteristic and I a
must be the minimum current
causing instantaneous tripping
The following diagram shows a Symmetra
®
MW installed in a TT system:
• Earthing arrangements and protective conductors - Symmetra
®
MW in “TT installation”