| Type | 
 | 
20NF250 | 
| Material | 
 | 
Porcelain | 
| Glaze Color | 
 | 
Brown | 
| Nominal Creepage Distance (mm) | 
 | 
500 | 
| Arcing Distance (mm) | 
 | 
310 | 
| Number of Sheds | 
 | 
4 | 
| Nominal Current (A) | 
 | 
250 | 
| Power Frequency Flashover Voltage (kV) | 
Wet | 
85 | 
| Dry | 
120 | 
| Power Frequency Withstand Voltage (kV) | 
Wet | 
55 | 
| Dry | 
115 | 
| Weight (kg) | 
 | 
6 |