User manual

Operation

Once the compressor is locked off, it will not come back on until the HP Alarm Counters (Service

Menu, Diagnostics) are reset to 0. Setting the counter to 0 will auto-reset the alarm without the need

of pressing the reset button on the display. Even if the pressure in the system drops below the alarm

point, the compressor will remain off until the system is reset.

3.1.3 Compressor Timing—Units With Two Compressors

To help maximize the life of your compressor(s), there is a start-to-next start delay for each single

compressor.

A Minimum ON time and a Minimum Off time may be selected in the Advanced menu (minimum

three minutes for single phase compressors). Consult the factory on how to modify the Minimum ON

and OFF time settings.

3.1.4 Compressor Sequencing

Compressor Sequencing parameter (Service Menu, Options Setup) is intended to maintain equal run

times between compressors. This setting has three selection possibilities:

• Always use Compressor 1 as lead compressor

• Always use Compressor 2 as lead compressor

• Auto:

• First priority: if the safety timings are acceptable for only one compressor, then it is the next

to be started/stopped.

• If both compressors are off: the one with fewer working hours is the next to start.

• If both compressors are in operation: the one that has been operating longer since the last

start is the next to be stopped.

NOTE

If the unit is equipped with manual reset high head pressure switches, or if the auto reset

high head pressure switches don’t reset, the compressor will not be turned back on, but there

will be a 30-second delay from when the high head pressure situation occurs and when the

alarm is annunciated.

NOTE

The Auto setting attempts to maintain equal run times between compressors.