Emerson VISSION 20/20 service manual

•Low Oil Pressure Safety Changeover = This is the length of time in which the normal Low (Run) Oil Pressure set-points will be massaged by the values of the Pre lube Oil Pressure set-points. After the timer has expired, the normal Low Oil Pressure set-points become active.

•High Filter Differential Pressure Safety Changeover = This timer bypasses the High Filter Differential Run Pressure safety settings when the compressor starts. It defines how long the High Filter Differential Start Pressure set-points will be active after the compressor starts. After the timer has expired, then the High Filter Differential Run Pressure safety set-points are active.

•Low Oil Separator Level Safety Changeover Timer = This timer bypasses the low oil level switch for momen- tary drops in the oil level. This timer activates when the low oil level switch opens, and deactivates when the switch closes. If the switch is still open after the timer has timed out, the compressor will be shut down and a trip message will be displayed. This timer is available if the unit is equipped with a low oil separator float switch (the oil level switch is standard on all liquid injection units and optional on all others).

•Low Oil Separator Temperature Safety Changeover = This timer allows Low Oil Separator Start Temperature safety set-point to protect the compressor against cold oil during starting. After the timer has expired, the Low Oil Separator Run Temperature is then active.

•Low Oil Injection Temperature Safety Changeover = This timer bypasses the Low Oil Injection Temperature Safety set-point during start-up, to allow any cold oil in the oil lines and filter to pass. After the timer expires, the Low Oil Injection Temperature safety is active.

•Max Restart After Power Failure = This timer forces the compressor to wait for the set time period after a power failure before it can be started automatically. By staggering the time settings of this timer between other compressor panels, the compressors can be allowed to start automatically, one at a time, after a power failure. This will prevent excessive load demand on the power system that could occur if all of the compressor equipment were to start at the same time. The Power-up Auto Re-Start [x]Enable option must be selected on the Timer screen for this option to be active.

•Hot Starts/Hr Counter = This counter counts compressor starts. After every start, a one-hour timer is reset and starts timing. If the timer times out, the hot starts counter is reset. When the counter reaches its preset value, it will not allow another compressor start until the one-hour timer times out and resets the counter. The hot starts counter, therefore, will be reset when the time between compressor starts total one hour. This counter allows repetitive compressor starts, but once the counter has reached its set point, it requires a one- hour window between compressor starts in order for the counter to be reset.

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