- The alternator relay provides a means of automatically alternating the operation of two separate air compressors.
- Time delay allows two separate units to be started and stopped at the same time without creating a power surge.
| Description | Part # |
| Automatic two compressor alternator relay 230 volt | ALT230 |
| Automatic two compressor alternator relay 460 volt | ALT460 |
| Hour meter (24 to 277 volt) | HRM75 |
| Hour meter for gas engines | HRM50 |
| Time delay 18 to 240 volt 1-1023 seconds | TD100 |
| Low oil control only (no fittings or extra wires) | 6304 |
| Float switch for low oil control only | 6304B |