17.5KV Switchgear

Yes, so long as the supply remains at most 17.5kv.

Yes, it is acceptable to install switchgear with highest system voltage for equipment 17.5 kV to operate at rated voltage of 13.8 kV; since your system does not require equipment with higher insulation levels.

The differences between 24 kV & 17.5 kV equipment are mainly related to the insulation levels; where the insulation levels of the 24 kV are higher than those of the 17.5 kV switchgear. Where,

- the power frequency withstand voltage for 24 kV system is 50 kV; while for 17.5 kV system is 38 kV;

- the lightning impulse withstand voltage for 24 kV are 95/125/145 kV; while for 17.5 kV system are 75/95 kV.

Regards,