Emerson 20/20 service manual Oil Separator Level #2 Safety Trip Delay

Section 8 • Timers

Low Oil Pressure Safety Bypass:

•This is the length of time in which the normal Low (Run) Oil Pressure setpoints will be adjusted by the values of the Pre-lube Oil Pressure setpoints. After the timer has expired, the normal Low Oil Pressure setpoints 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 setpoints will be active after the compres- sor starts. After the timer has expired, then the High Filter Differential Run Pressure safety setpoints will be active.

Oil Separator Level #1 Safety Trip Delay:

•This timer bypasses the low oil level switch for mo- mentary 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 af- ter 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).

Oil Separator Level #2 Safety Trip Delay:

•This timer bypasses the low oil level switch for mo- mentary 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 af- ter 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 setpoint 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 Safety Bypass:

•This timer bypasses the Low Oil Injection Temperature Safety setpoint 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 and the panels re- starts before it can be started automatically. By stag- gering 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 com- pressor equipment were to start at the same time. The Power-up Auto Re-Start [x]Enable option must be selected on the Configuration screen for this op- tion to be active.

Hot Starts per Hour:

•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 be- tween compressor starts total one hour. This coun- ter 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.

True Anti-Recycle Timer:

•Once the compressor turns off, this timer will keep the compressor off for the setting of the True Anti- Recycle Timer. This timer is used to prevent short cy- cling of the compressor.

Accumulative Anti-Recycle Timer:

•This timer forces a specified time between compres- sor starts. When the compressor starts, the timer resets and starts timing and accumulates running time. Once the compressor shuts down, it will not be allowed to restart for the remainder of time left on the Accumulative Anti-Recycle Timer. Unlike the True Anti-Recycle Timer, if the compressor has run for a time period that exceeds the setpoint of the Accumulative Anti-Recycle Timer, then when the compressor shuts down, it will be allowed to restart immediately.

Compressor Interlock Bypass:

•Once the Vission 20/20 has sent a command to the compressor starter to start, a return signal is expect- ed. This timer defines how much time to wait for that signal before setting a trip condition.

High Motor Amps Safety Bypass:

•Starting motors can typically pull much more than its rates full load amps for a short time. This timer ig- nores that sudden inrush of current for the specified time.

Emergency Stop Timer:

•Defines the amount of time the compressor is in a False start condition before activating the Emergency stop. The emergency stop output can be connected to a shunt-trip in the case of a run away compressor

8 – 2 Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 1.8.5153