13-8-623 Page 12
The "AUTO SENTRY RS2000" controller is designed for systems of two through eight compressors piped
into a common air receiver 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 eliminates the need to operate "spinning reserve" of unloaded
compressors. This storage may be an air receiver, 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
control system will operate only as many compressors as are needed to supply the CFM demand of the
plant, and to maintain the compressor system pressure between the LOAD and UNLOAD pressures
programmed into the controllers.
The controllers are completely set up to operate this system. The only required additional part is the
cable which runs from controller to controller. A kit, 200EAP752, is available which contains all material
needed to sequence up to five compressors. This kit contains 500 feet of cable, eight modular
connectors, and a crimping tool to install the connectors.
In spite of the fact that it is a standard feature and its inherent installation simplicity, the sequencing
function of a multi-compressor "AUTO SENTRY " system is the most fully-featured, functionally-complete
available today.
Compressor System -
A proper sequencing installation requires two or more Gardner Denver rotary air
compressors complete with "AUTO SENTRY RS2000" controllers, piped into a common air system,
interconnected as described above. For best performance, connect the units directly to a common
header and receiver, without any intervening dryers, filters, or other restrictions. If any equipment must
be installed on individual compressors, select equipment with minimum pressure drop. If filters are
installed, establish a maintenance procedure to prevent clogging filters from upsetting the system. There
should be no check valves or other devices which isolate a member from the air system. During
operation, be sure that any unit is taken out of the sequence mode before closing its service valve.
The receiver should also be sized to prevent excessive drops or rapid rises in pressures during the
operation as described below. Note that "receiver" really applies to the entire storage volume of a
physical receiver and the volume of the air distribution throughout the plant.
With load-unload compressors, large volume or wide differential may be needed to prevent unnecessary
starts or rapid compressor cycles. Note that when demand exceeds the capacity of the running unit(s),
there will be a delay until the next unit starts and delivers additional air. The stored air serves the plant
during this period. With a properly sized receiver, pressure changes on a receiver gauge should be very
slow and gradual.
All standard practices common to sound air compressor installations such as proper sizing of piping,
proper electrical supply and conductor sizing, and grounding are to be observed. Run the compressors
in the system in Automatic mode for at least one week to evaluate system performance.
Sequencing Installation -
Once the compressor system is set up, sequencing compressors with the
controller is as simple as plugging in a telephone to a wall jack. The only item required to make the
system functional is a cable similar to a phone cable. The cable and connectors used in kit 200EAP752
have been specially selected to meet the needs of an industrial application. One less cable than the
number of compressors to be sequenced is required. For example, to sequence four compressors, three
cables are required.
The serial communications interface meets RS-485 standards, the most widely used interface in harsh,
industrial environments today. However, the communications cables should be routed through metallic
conduit to provide them with both mechanical protection and electromagnetic shielding. Do not run the
communications cable in a conduit with other wiring.
Summary of Contents for AUTO SENTRY RS2000
Page 11: ...13 8 623 Page 7 Figure 3 1 FLOW CHART FOR SETUP PROGRAMMING V4 xx 300EBC1255 E Ref Drawing...
Page 21: ...13 8 623 Page 17 300EFC546 A Ref Drawing Page 1 of 2 Figure 3 2 TYPICAL WIRING DIAGRAM V4 xx...
Page 22: ...13 8 623 Page 18 WIRING DIAGRAM 300EFC546 A Ref Drawing Pag 2 of 2...
Page 30: ...13 8 623 Page 26 FIGURE 4 2 TYPICAL WIRING DIAGRAM V6 xx 303EFC546 A Ref Drawing Page 1 of 2...
Page 31: ...13 8 623 Page 27 303EFC546 A Ref Drawing Page 2 of 2...
