Emerson Vission Control Manual page 39

· Minimum Compressor Prelube Timer – This is the
length of time the oil pump will run after establish-
ing the Prelube Oil Pressure, to prime oil circuit
before starting the compressor.
· Oil Pressure Bypass At Compressor Start – This
timer bypasses the Low Oil Pressure limits. The
timer starts when the compressor starts. After the
timer has cycled, the Low Oil Pressure setpoint is
active.
· Prelube Oil Pump Time Limit – This timer puts a
limit on how long the prelube oil pump is allowed
to run without establishing the Prelube Oil Pres-
sure.
· Filter Differential Pressure Safety Changeover –
This timer bypasses the Hi Run Filter Differential
Pressure setting during start, to allow the Hi Start
Filter Differential Pressure to protect against High
Filter Differential during start. After the timer has
cycled, the Hi Run Differential Pressure Safety is
active.
· Low Oil Separator Level Bypass Timer – This timer
bypasses the low oil level switch for momentary
drops in the oil level. If the switch is still open
after the Low Oil Separator Level Bypass Timer
has timed out, the compressor will be shut down
and an alarm will be displayed. This timer is avail-
able 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.
· Auto Restart After Power Failure – This timer
forces the microprocessor to wait for the set time
period after a power failure before starting the com-
pressor unit. By staggering the time settings, the
compressors can be allowed to start automatically,
one at a time, after a power failure. This prevents
excessive loads on the power system that could be
caused by all of the equipment coming online at the
same time. The Power-Up Auto Start operator op-
tion must be selected on the Setup screen for this
option to be active.
Compressor Timer Setpoints
· Oil Separator Temperature Safety Changeover
– This timer allows Low Oil Separator Start
Temperature Safety setpoint to protect the com-
pressor against cold oil during starting. After
the timer has cycled, the Low Oil Separator Run
Temperature is then active.
· Low Oil Injection Temperature Bypass – This
timer bypasses the Low Oil Injection Tempera-
ture Safety Setpoint during start-up. After the
timer cycles, the Low Oil Injection Tempera-
ture Safety is set.
· 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 it's preset value, it will not al-
low another compressor start until the one-hour
timer times out and resets the counter. In other
words, the hot starts counter will be reset when
the time between compressor starts total one
hour. This counter allows repetitive compres-
sor 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 compres-
sor turns off, the timer will keep the compres-
sor off for the setting of True Anti-Recycle
Timer. This timer is used to prevent short cy-
cling of the compressor.
· Accumulative Anti-Recycle Timer – This timer
also forces a specified time between compres-
sor starts. When the compressor starts, the timer
resets then starts timing and accumulates run-
ning time. Once the compressor shuts down, it
will not be allowed to restart for the remainder
of the time left on the Accumulative Anti-Re-
cycle Timer. Unlike the True Anti-Recycle
Timer, if the compressor has run for a time pe-
riod that exceeds the setpoint of the Accumula-
tive Anti-Recycle Timer, then when the com-
pressor shuts down, it will be allowed to restart
immediately.
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