Gardner Denver ELECTRA-SAVER EAYQ E, Руководство по эксплуатации и обслуживанию

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13–10–613 SP Page 26
to 0.2 seconds is normally adequate for factory–
furnished full–voltage starters; wye–delta or re-
mote starters may require a little more time. Set
back to zero to proceed to the next step.
9. In the top line, “AUX SD MESSAGE” is displayed.
The bottom line will display the message which will
appear if power is removed from terminal 7. Se-
lect the most appropriate message for user–fur-
nished shutdown devices, and press [ENTER] to
proceed.
10. This completes the unit setup adjustments. The
controller will return to the main adjustments
menu.
OTHER CONTROL FEATURES
Modulating – Load / Unload – The ES+ controller of-
fers two control modes, to suit the needs of different ap-
plications with different storage capacity.
When set for “MODULATING”, the controller will start
and load whenever the pressure drops below the reset
pressure. Continuous modulation by the turn–valve (if
so equipped) and the inlet valve will maintain the dis-
charge pressure near the set pressure for any CFM de-
mand from full capacity to very light demand. The inlet
and turn valves are coordinated to always use the most
efficient and appropriate control. At very light or zero
demand, the compressor will completely unload, blow-
down, and stop as appropriate for the selected operat-
ing mode. This is the normal control mode for the com-
pressor, and is preferred for almost all applications.
When set for “LOAD–UNLOAD”, the controller will
start and load whenever the pressure drops below the
reset pressure. When the pressure rises to the set
pressure, it completely unloads. If the blowdown timer
has not timed out, the compressor will reload when the
system pressure drops below the midpoint between set
and reset pressure. If the blowdown timer has timed
out, the reservoir will blow down, and reload will not oc-
cur until the pressure drops below the reset pressure.
Use a large receiver volume or wide difference be-
tween set and reset pressure to prevent rapid cycling.
Current Limiting – Current limiting is available when
an ES+ controller is used on a compressor unit with
turn valve control and has current monitoring installed.
This is based on the motor service factor amps pro-
grammed above.
On units with turn valves, the controller will unload as
required to prevent operation above the programmed
service factor amps. This continues operation of the
compressor at reduced delivery, but within the pro-
grammed limit. This limiting will occur in either the
modulating or the load–unload mode of operation.
This feature takes control only if operating conditions
are outside of the compressor unit’s design range. Low
operating voltage, in particular, can cause high amp
draw. This will heat the motor beyond its design, and
will normally trip the overload relay to prevent motor
failure. The ES+, however, will automatically reduce
the delivery to continue operation within design limits.
If severe conditions persist, The controller will display
“HIGH MOTOR AMPS.”
This feature is also coordinated with the ES+ sequenc-
ing controls. During low voltage conditions, lead units
will operate only up to their limits. If necessary, another
compressor will start to meet the air demand.
Auto Restart After Power Failure – The ES+ control-
ler normally displays “SHUTDOWN – POWER FAIL-
URE” after power has been interrupted and restored.
Press the STOP / RESET key and select an operating
mode to restart the compressor.
If programmed for automatic restart, The ES+ control-
ler pauses and begins counting down when power is re-
stored. This time is adjustable in the programming
steps noted above. This must be at least several se-
conds, but may be set longer to allow other plant loads
to start up first. After the countdown is complete, the
ES+ controller resumes the mode of operation prior to
the power interruption.
If this is enabled in a sequenced system, set all of the
timers to the same value. All ES+ controllers will the
resume the same sequence numbers which they had
prior to the interruption. The ES+ sequence controls
will start the lead unit after the start timer countdown,
and add units individually as required, based on the lag
start delay.
SEQUENCING COMPRESSORS WITH THE AUTO
SENTRY–ES+
General – The sequencing mode is used to operate
multiple compressors in a common plant air system.
The individual units operate similarly to operation in the
automatic mode, except that the setpoints are under
control of the sequencing system. This system is actu-
ally distributed among the individual ES+ controllers
and compressor units, with communications between
them to keep the system coordinated. Sequencing is
intended to start, run, unload, blowdown, and stop
compressors in response to changes in demand during
the day or week.
The ES+ controller is designed for systems of two
through eight compressors piped into a common air re-
ceiver for distribution to the plant. In any such system,
the receiver is an important part of the application; it
supplies air to the plant and allows compressor units to
be unloaded and stopped. This stored reserve elimi-
nates the need to operate “spinning reserve” of un-
loaded compressors. This storage may be an air re-
ceiver, or may be the volume of air in a large distribution
system. In either case, the compressors must be piped
to this volume with a minimum of restriction. The ES+