What are insulation levels?
There are six insulation levels in all, each with a maximum allowable temperature. Safety standards each specify the applicable insulation level.
| Insulation level | Maximum allowable temperature |
| Class Y | 90°C |
| Class A | 105°C |
| Class E | 120°C |
| Class B | 130°C |
| Class F | 155°C |
| Class H | 180°C |
| Safety standard | Insulation level |
| UL | Class A |
| CSA | Class B |
| VDE | Class E or B |