Nii IIIB kui ka IIIC on tolmuses keskkonnas kasutatavate plahvatuskindlate elektriseadmete klassifikatsioonid, kusjuures IIIC on IIIB-st kõrgemal tasemel.
| III | C | T 135°C | Db | IP65 |
|---|---|---|---|---|
| III Pinnatolm | T1 450°C | Ma | IP65 | |
| T2 300°C | Mb | |||
| T3 200°C | ||||
| A Süttivad lendavad flokid | Da | |||
| T4 135°C | ||||
| Db | ||||
| B Mittejuhtiv tolm | T2 100°C | Dc | ||
| C Juhtiv tolm | T6 85°C |
In environments categorized as IIIA, IIIB, or IIIC, IIIC locations pose the greatest risk. IIIC explosion-proof servo motors are appropriate for use in IIIB dust environments, whereas IIIB motors are not intended for use in gaseous environments.
All explosion-proof servo motors are classified as IIIC, making them suitable for a range of dusty conditions.
