Gardner Denver Governor User manual

13-17-625
Version: 00
July 15, 2020
Governor™ Controller
MULTI-MACHINE SEQUENCING MANUAL
7” | 4.3” Governor Compressor Applications

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WARNING –PROHIBITION –MANDATORY LABEL INFORMATION
Gardner Denver compressors are the result of advanced engineering and skilled manufacturing. To be
assured of receiving maximum service from this machine, the owner must exercise care in its operation
and maintenance. This book is written to give the operator and maintenance department essential
information for day-to-day operation, maintenance and adjustment. Careful adherence to these instructions
will result in economical operation and minimum downtime.
Boxed text formats are used, within this manual, to alert users of the following
conditions:
Safety Labels are used, within this manual and affixed to the appropriate areas of
the compressor package, to alert users of the following conditions:
Indicates a hazard with a high level of risk, which if not avoided, WILL result in death or serious injury.
Equipment Starts Automatically
Cutting of Finger or Hand Hazard –Rotating
Impeller Blade
Cutting of Finger or Hand Hazard –Rotating Fan
Blade
Health Hazard –Explosive Release of Pressure
High Voltage –Hazard of Shock, Burn, or Death
Present until Electrical Power is Removed
Entanglement of Fingers or Hand/Rotating Shaft

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Indicates a hazard with a medium level of risk which, if not avoided, COULD result in death or
serious injury.
Asphyxiation Hazard –Poisonous Fumes or Toxic Gases in Compressed Air
Indicates a hazard with a low level of risk which, if not avoided, MAY result in a minor or
moderate injury.
Burn Hazard –Hot surface
PROHIBITION/MANDATORY ACTION REQUIREMENTS
Do not Operate Compressor with Guard Removed
Do Not Lift Equipment with Hook –No Lift Point
Handle Package at Forklift Points Only
Lockout Electrical Equipment in De-Energized
State
Loud Noise Hazard –Wear Ear Protection
Read the Operator’s Manual Before Proceeding
with Task

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SAFETY PRECAUTIONS
The following text presents common safety issues of which the user should be aware. Though the
list below includes unit and supporting equipment dangers present, the user must also be vigilant
to other hazards introduced in an industrial environment, and ensure they have received the
necessary safety training.
Failure to observe these notices will result in injury to or death of personnel.
Keep fingers and clothing away from rotating fan, drive coupling/belting, etc.
Disconnect the compressor unit from its power source, lockout and tagout before working on the
unit –this machine is automatically controlled and may start at any time.
Do not loosen or remove the enclosure or belt covers, or break any connections, etc., in the
compressor air system until the unit is shut down and the air pressure has been relieved.
Electrical shock can and may be fatal.
Perform all wiring in accordance with the National Electrical Code (NFPA-70) and any applicable
local electrical codes. Wiring and electrical service must be performed only by qualified
electricians.
Open main disconnect switch, lockout and tagout and check for voltage before working on the
control.
Failure to observe these notices could result in damage to equipment.
Stop the unit if any repairs or adjustments on or around the compressor are required.
Do not use the air discharge from this unit for breathing –not suitable for human consumption.
An Excess Flow Valve should be on all compressed air supply hoses exceeding 1/2 inch
inside diameter (OSHA Regulation, Section 1926.302).
Do not exceed the rated maximum pressure values shown on the nameplate.
Do not operate unit if safety devices are not operating properly. Check periodically. Never
bypass safety devices.

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Table of Contents
1. GENERAL INFORMATION......................................................................................................................7
1.1 SYSTEM DESIGN....................................................................................................................................7
1.2 HARDWARE ...........................................................................................................................................7
1.3 SOFTWARE............................................................................................................................................8
1.4 SYSTEM CONNECTIONS .........................................................................................................................8
2. SUPPORTED PROTOCOLS..................................................................................................................10
2.1 AIRSMART PROTOCOL.........................................................................................................................10
2.3 DELCOS PROTOCOL.............................................................................................................................11
2.4 ES+ PROTOCOL..................................................................................................................................11
3. SEQUENCING USING THE AIRSMART™ PROTOCOL......................................................................12
3.1WIRING CONNECTIONS ........................................................................................................................12
3.2 COMMUNICATION CONFIGURATION .......................................................................................................14
3.3OPERATING MODE SETTING.................................................................................................................16
3.4 SEQUENCING SETTINGS.......................................................................................................................16
3.5 PROGRAMMABLE IO CONFIGURATION...................................................................................................18
3.6 AIRSMART SYSTEM OPERATION...........................................................................................................19
3.7 AIRSMART SEQUENCING DIAGNOSTICS.................................................................................................20
4. SEQUENCING USING THE DELCOS PROTOCOL..............................................................................22
4.1WIRING CONNECTIONS ........................................................................................................................22
4.2 COMMUNICATION CONFIGURATION .......................................................................................................23
4.3OPERATING MODE SETTING.................................................................................................................24
4.4 SEQUENCING SETTINGS.......................................................................................................................25
4.5 DELCOS SEQUENCING SYSTEM OPERATION..........................................................................................27
4.6 DELCOS SEQUENCING DIAGNOSTICS....................................................................................................28
5. ES+ .........................................................................................................................................................32
THIS SECTION PROVIDES DETAILS ON CONFIGURATION AND OPERATION OF THE SYSTEM IN ES+ SEQUENCING.32
5.1WIRING CONNECTIONS ........................................................................................................................32
5.2 COMMUNICATION CONFIGURATION .......................................................................................................34
5.3OPERATING MODE SETTING.................................................................................................................35
5.4 SEQUENCING CONFIGURATION.............................................................................................................36
5.4 ES+ SYSTEM OPERATION....................................................................................................................38
5.4.1 Establishing the Initial Sequence...............................................................................................38
5.4.2 How the ES+ Controls Pressure While Sequencing..................................................................39
5.5 SEQUENCING DIAGNOSTICS .................................................................................................................40

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Table of Figures
FIGURE 1: SEQUENCING PRESSURE CONNECTIONS ..........................................................................................8
FIGURE 2: EXAMPLE -MASTER WITH THREE SLAVE MACHINES...........................................................................9
FIGURE 3: EXAMPLE RS485 CONFIGURATIONS OF THE MASTER/SLAVE CONTROLS FOR COMMUNICATIONS........10
FIGURE 4: SYSTEM PRESSURE TRANSDUCER WIRING ON IO MODULE USING CABLE VP1033693 .....................12
FIGURE 5: AIRSMART RS485 COMMUNICATION WIRING SCHEMATIC ...............................................................13
FIGURE 6: IO MODULE DIP SWITCH SETTINGS AT RS485-1 PORT ..................................................................13
FIGURE 7: BLUE IS RS485 GND, ORANGE IS RS485+, WHITE IS RS485-.......................................................14
FIGURE 8: BLUE IS RS485 GND, ORANGE IS RS485+, WHITE IS RS485-.......................................................14
FIGURE 9: MENU NAVIGATION TO COMMUNICATIONS SCREEN...........................................................................15
FIGURE 10: AIRSMART COMMUNICATIONS CONFIGURATION SCREEN...............................................................15
FIGURE 11: MENU NAVIGATION TO CONTROL SETTINGS..................................................................................16
FIGURE 12: OPERATING MODE SETTING IN CONTROL SETTINGS MENU............................................................16
FIGURE 13: MENU NAVIGATION TO SEQUENCING SCREEN.................................................................................17
FIGURE 14: SEQUENCING SETTINGS SCREEN .................................................................................................17
FIGURE 15: PROGRAMMABLE IO SETTINGS SCREEN .......................................................................................19
FIGURE 16: AIRSMART SEQUENCING DIAGNOSTICS MENU NAVIGATION ...........................................................20
FIGURE 17: AIRSMART SEQUENCING DIAGNOSTICS PAGE...............................................................................21
FIGURE 18: DELCOS RS485 COMMUNICATION WIRING SCHEMATIC.................................................................22
FIGURE 19: IO MODULE DIP SWITCH SETTINGS AT RS485-1 PORT ................................................................23
FIGURE 20: MENU NAVIGATION TO COMMUNICATIONS SCREEN .......................................................................23
FIGURE 21: DELCO'S COMMUNICATION CONFIGURATION SCREEN....................................................................24
FIGURE 22: MENU NAVIGATION TO CONTROL SETTINGS..................................................................................24
FIGURE 23: OPERATING MODE SETTING IN CONTROL SETTINGS MENU............................................................25
FIGURE 24: MENU NAVIGATION TO SEQUENCING SCREEN...............................................................................26
FIGURE 25: DELCOS SEQUENCING SETTINGS SCREEN....................................................................................26
FIGURE 26: DELCOS SEQUENCING DIAGNOSTICS MEU NAVIGATIONS...............................................................29
FIGURE 27: DELCOS DEQUENCING DIAGNOSTICS PAGE FOR A MASTER...........................................................30
FIGURE 28: DELCOS SEQUENCING DIAGNOSTICS PAGE FOR A SLAVE ..............................................................30
FIGURE 29: DELCOS KEYBOARD TO CHANGE NAME OF MASTER MACHINE .......................................................31
FIGURE 30: DELCOS CHANGE BLS RUN HOURS .............................................................................................31
FIGURE 31: ES+ RS485 COMMUNICATION WIRING SCHEMATIC ......................................................................32
FIGURE 32: LEGACY ES+ RS485 COMMUNICATION WIRING TO GOVERNOR DISPLAY .......................................33
FIGURE 33: RJ-12 TO TERMINAL BREAKOUT CONNECTOR (GD PN: TEN023981)...........................................34
FIGURE 34: MENU NAVIGATION TO COMMUNICATIONS SCREEN.........................................................................35
FIGURE 35: ES+ COMMUNICATIONS CONFIGURATION SCREEN........................................................................35
FIGURE 36: MENU NAVIGATION TO CONTROL SETTINGS..................................................................................36
FIGURE 37: OPERATING MODE SETTING IN CONTROL SETTINGS MENU............................................................36
FIGURE 38: MENU NAVIGATION TO SEQUENCING SCREEN...............................................................................37
FIGURE 39: ES+ SEQUENCING SETTINGS SCREEN..........................................................................................37
FIGURE 40: ES+ SEQUENCING DIAGNOSTICS MENU NAVIGATION....................................................................40
FIGURE 41: ES+ SEQUENCING DIAGNOSTICS PAGE FOR A MASTER/SLAVE......................................................41

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1. General Information
Compressor sequencing refers to the intelligent control of system consisting of multiple compressors to
provide a single compressed air supply. This is done to optimize energy efficiency, pressure control, and
maintenance schedules of the system.
The Gardner Denver Governor™ controller is capable of communicating with several different generations
of Gardner Denver controls to allow multi-machine sequencing of new and existing Gardner Denver
equipment. Depending on the protocol selected, up to 4 or 8 machines may be sequenced on a single
installation without the use of a master controller.
This manual describes the requirements, configuration / installation, and operation of compressors under
sequencing control with the Gardner Denver Governor™ controller. Note: All Governor Controller
screenshots in this manual are for the 7” screen, however the 4.3” screens and settings are very similar
and are located in the same location in the menus.
The following requirements must be met to ensure proper operation of the system.
1.1 System Design
In order for the system to be sequenced reliably, all compressors must be connected to an air
storage system with minimal pressure differential between machines and adequate storage for the
system. The machines must also be selected to work in a coordinated manner based on the demand
profile. If these requirements are not met, the system may not be able to adequately meet the
customer’s requirements.
A proper sequencing installation requires two or more Gardner Denver rotary air compressors with
supported controllers, piped into a common air system, interconnected as described above.
Connect the units directly to a common header and receiver, without any intervening dryers, filters,
or other restrictions. 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. Modulating systems
work best when the receiver is at least one gallon for the rated CFM of a member compressor in the
system (the largest if they differ). 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. It is recommended
that the compressors are run in Automatic mode for at least one week to evaluate system
performance before activating sequencing.
1.2 Hardware
All of the supported sequencing protocols use an RS485 serial network for communications. RS485
is an industrial communications network that is suitable for robust communications in industrial
networks, but proper installation is still important to ensure reliability.
Gardner Denver provides kit number 317AUX6028 which includes all hardware required to add a
machine to a new or existing sequencing network. This includes cable glands, cable, and
components to add a system pressure sensor to the machine (utilized for the AirSmart protocol). If
the Gardner Denver-supplied kit is not used, it is important that the communications cable is 3-wire

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shielded cable suitable for industrial environments. The parts list for 317AUX6028 is shown in Table
1.
Table 1: 317AUX6028 Sequencing Kit
Part Number
Description
Quantity
24CA2865
FITTING-ELECTRICAL .125-.25 1/2"CONDUIT
2
64EB368
COUPLING-PIPE 1/4FPT 3/J-16 COUPLING
1
88H369
TRANSDUCER-PRESSURE 15BAR 4-20mA, 1/4NPT
1
64AC2
PLUG 1/4" NPT HEX SOCKET HEAD PRESSURE
1
97J93
CABLE,3 COND,FOIL/SHIELD W/ 22 AWG TWIST
100 ft
VP1033693
HARNESS-WIRING
1
24A77
LOCKNUT-CONDUIT
2
24A383
O-RING SEALING 1/2"
2
1.3 Software
It is recommended that all machines in the sequenced network have the most up-to-date software
available installed. The most up to date software ensures that the machines have all of the latest
features and operate as intended. Check GD Inside for any available software updates.
1.4 System Connections
The system connections for sequencing configurations are shown below. The air and pressure
connections for the system is shown in Figure 1. Note that the system pressure feedback is only
required for AirSmart protocols. The “AirSmart Controller” in the figure would be replaced by either
Delcos or ES+ when configuring those systems.
Figure 1: Sequencing Pressure Connections
AirSmart
Controller 1
AirSmart
Controller 2

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Figure 2 shows an example of a sequenced set of machines where there is a single master and
three slave machines, or a group of 4 sequenced peer machines.
For the AirSmart and ES+ protocols, any machine in the sequenced network can
automatically take on the role of master or slave depending on the system configuration
and the machines running.
When using the Delcos protocol, the master machine is dedicated and selected through
the controller configuration. For any Delcos network using a Governor controller, a
machine with a Governor controller must be configured as the master of the network.
Figure 2: Example - Master with three Slave Machines
Figure 3 shows example RS485 wiring connections from the master machine to each of the slave
machines in the sequenced system of machines. The communications interface must form a bus
structure so that all compressors are connected in series.

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Figure 3: Example RS485 configurations of the Master/Slave controls for communications
2. Supported Protocols
The Governor™ controller will communicate with several different Gardner Denver sequencing protocols.
For new installations, any mode may be used and selected based on the features of the installation. This
section provides some basic information on each protocol to help you determine the best option for your
system. Once you have selected the best protocol for your application, refer to the detailed instructions in
the following sections specific to that protocol.
2.1 AirSmart Protocol
The AirSmart protocol is the native protocol for fixed and variable speed compressors using the
AirSmart or AirSmart G2 controller. If you are connecting to other Gardner Denver compressors
with these controllers, the AirSmart protocol should be used to allow for direct and optimal
sequencing control. The AirSmart protocol is uniquely designed to handle sequencing and load
sharing of variable speed compressors or a mix of up to 8 variable speed and fixed speed
machines. It also features the ability to use a dedicated system pressure input to sample a true
network delivery pressure.
The system will automatically determine the master of the network based on machine size and total
hours. In addition, all variable speed machines will be run at the same load percentage based on
the master’s command to optimize system pressure and equalize load across all running units. If
the set maximum load percentage for the network is met and more machines are required to meet
demand, machines will be started in a controlled manner before allowing the system to run all
machines at 100% capacity. Likewise, if all running machines are operating at the set minimum

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percent load for the network and pressure exceeds the unload pressure setting, machines will be
removed from operation, preventing the entire network from running at a low capacity when not
required.
2.3 Delcos Protocol
The Delcos protocol is the native protocol for Gardner Denver machines using the GD Pilot, GD Pilot
TS, GD Pilot XTC, Delcos Pro, Delcos XL, and Delcos XXL controllers. If you are connecting to other
Gardner Denver compressors with one of these controllers, this is the protocol that should be used.
It is also the protocol to select if you are using a Gardner Denver Connect 12™ system controller.
The Delcos protocol can sequence up to 4 compressors. One of the compressors must be
configured as the master, with up to 3 slaves connected, as shown above in Figure 2.
While using Delcos protocol, all the slave machines run off the master machine’s delivery pressure
sensor. The master machine can be either fixed speed or variable speed, but all slave machines
must be the same type for the system to function properly.
2.4 ES+ Protocol
The ES+ protocol is the native protocol for Gardner Denver machines using the Auto Sentry ES+
Controllers. Only fixed speed machines may be sequenced using the ES+ protocol.
The ES+ protocol was designed to optimize systems of machines with turn valve and inlet valve
modulation so that air requirements are met and machines are not run when they are not required.
In ES+ mode, the system will automatically rotate the lead of the system, and will vary the amount
of modulation across the machines in the system to save energy.
The ES+ protocol is the best choice if you are installing into a system of existing machines with
ES+ controllers. The protocol will function most efficiently if all machines in the network are
relatively similar in flow capacity.

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3. Sequencing Using the AirSmart™ Protocol
This section describes how to connect and configure machines using the AirSmart™protocol.
3.1 Wiring Connections
-
Example machine wiring connections for the AirSmart sequencing protocol are detailed below. A
System Pressure feedback input is required for AirSmart sequencing. However, if desired, the
Delivery Pressure of the compressor may also be configured for sequencing in some cases and is
explained in more detail below this section. The pressure transducer wiring to the Governor
controller IO Module can be found in Figure 4 using the cable provided in the sequencing kit. The
compressor network may be comprised of any combination of Governor, AirSmart, and AirSmart
G2 controlled machines, as well as ES+ machines equipped with a PCM module.
Figure 4: System Pressure Transducer Wiring on IO Module using cable VP1033693
Daisy chain the RS485 connections from the master machine to the first slave machine then
second slave machine, etc. for each machine in the sequenced group. The AirSmart RS485
connections are located on the IO Module at X02 in the control cabinet. The wiring diagram is
shown in Figure 5. RS485-2 at X03 on the IO module can also be used if present on the machine.
Setup and configuration for RS485-2 is identical to RS485-1.

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Figure 5: AirSmart RS485 Communication Wiring Schematic
Figure 6 is the hardware Interface for the RS485 Connections on the IO Module shown in the wiring
diagram in Figure 5. Make sure that the machines at the end of the sequencing network have the
RS485 terminating resistor DIP switch in the ‘ON’ position. The location of the terminating resistor
selection for X02 is highlighted below in Figure 6.
Figure 6: IO Module DIP Switch Settings at RS485-1 Port
Figure 7 shows the RJ-45 adapter (PN: 24CA7402) used on existing AirSmart G2 control
systems which use an RJ45 connector for the sequencing network. This part is included in the
AirSmart G2 sequencing kit, and should be utilized if connecting to an existing network of
AirSmart G2-controlled machines. Using the cable supplied in the sequencing kit, the
terminations on the connector are as follows: GND or C on terminal 8, RS485 + on terminal 2,
and RS485 - on terminal 1. With the RS-45 pins facing upwards as shown below, the topmost
terminal is referred to as terminal 1.

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Figure 7: Blue is RS485 GND, Orange is RS485+, White is RS485-
Figure 8 shows the serial connection on the communications module on AirSmart machines
using the cable supplied in the sequencing kit. The communications module may be used on
machines in the field using AirSmart control systems. The RS485 serial port for sequencing is
located at P19.
Figure 8: Blue is RS485 GND, Orange is RS485+, White is RS485-
3.2 Communication Configuration
In order to set up communication between the machines, the RS485 communications will need to
be configured on the controller. AirSmart sequencing requires a baud rate of 19200, which will be
set automatically after selecting the sequence mode.
Navigate to the communication settings by selecting Menu, Settings, Configuration, and then
Communication, shown in Figure 9. Select the RS485-1 tab then change the mode to Sequence
–AirSmart. Machines which have RS485-2 at X03 populated will show an additional tab called

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“RS485-2” in the menu with the same settings available. Use the port that corresponds to the
physical location of the wiring connections on the machine.
Figure 9: Menu navigation to communications screen
Please note that the controller may prompt the user to reboot following the mode change of the
communication parameters. Select OK and allow the controller to reboot before continuing with
the additional settings.
Figure 10: AirSmart Communications Configuration Screen

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3.3 Operating Mode Setting
Next, the operating mode for machine control needs to be configured. Navigate to the control
settings menu following Figure 11 by selecting Menu, Settings, and then Control. Change the
operating mode to Sequencing, shown in Figure 12.
Figure 11: Menu Navigation to Control Settings
Figure 12: Operating Mode Setting in Control Settings Menu
3.4 Sequencing Settings
Next, navigate to the sequencing settings menu as shown in Figure 13. Figure 14 shows the
sequencing settings screen and all of the different settings that can be configured. Table 2 at the
end of this section outlines the settings associated with the AirSmart sequencing protocol in more
detail and shows the default parameters that are set in the controller. The parameter settings are
different depending on the sequence mode selected while configuring the RS485 communication
settings. The Capacity settings will vary depending on the machine size, while other default values

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will be constant. For AirSmart mode the master/slave designation can change based on the
capacity and total machine run hours for priority of master control.
Figure 13: Menu navigation to sequencing screen
Figure 14: Sequencing Settings Screen

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Table 2: AirSmart Multi-Machine Sequencing Settings
3.5 Programmable IO Configuration
Next, the System Pressure input needs to be assigned on the Programmable IO settings page.
The AirSmart protocol requires a pressure sensor input representing the system pressure that is
measured at the system storage in order for a machine to be considered capable of being a
master on the network. An additional system pressure transducer connected to an open analog
input on the IO module at X11 is typically used for this and will need to be properly addressed.
The system pressure transducer shown in the diagram above in Figure 4 is connected to Analog
Input 3 on the IO module. The mapping of this location would correspond to Channel 3 for the
Sequence System Pressure, as shown below in Figure 15.
Machine delivery pressure may also be used in place of the system pressure transducer, if
desired. This is only recommended for small installations where there is little differential between
the delivery pressure and the system pressure, as well as between the delivery pressure of the
machines in the sequencing network. In this case, the channel that is assigned to Delivery
Pressure may be assigned to System Pressure on the Programmable IO configuration and the
controller will use this pressure signal for both purposes. On many machines, delivery pressure is
on Analog Input 2, but refer to the wiring diagram for your machine to verify this value.
Settings
Default Values
Description
Unit Number
1
A number between one and eight assigned to each machine in sequence. No two
machines can share a unit number.
Transfer
Interval
4 hours
Controls how frequent the Leader role is transferred. The leader role will be transferred
to another capable master of the same capacity when the difference between the run
hours of the two machines is equal to the Transfer Interval.
Fault Action
Local
This value may be set to Local or Wait. Indicates what a slave compressor (one that
cannot become master because no system pressure transducer is assigned) should do
when it no longer receives data from a master compressor. Local: modulate the pressure
based on the compressor’s own delivery pressure sensor and use the compressor’s own
set points. Wait: blowdown and stop compressor until communication with a valid master
compressor is reestablished. Note that the AirSmart controller does not have this setting
and will utilize the Wait behavior described above.
Lag Start
Delay
15 seconds
The Lag Start Delay is a value in seconds that sets amount of time the Master will wait
between commands to other machines in the system. This ensures that machines are
not brought on or offline too quickly. In most cases the default value of 15 seconds
should be used.
Capacity
700 CFM
Capacity value in CFM used to decide which machine is the Master in the sequence.
The largest machine capable of running as a master will always be the master in the
sequence, so Capacity values must be set to the same value for all machines that you
wish to rotate as the master of the system.
Transfer Load
Decrement
35%
Transfer Load Decrement sets the minimum percent load the network will run before
unloading one of the slave compressors due to pressure exceeding the unload setpoint.
Transfer Load
Increment
80%
Transfer Load Increment sets the maximum percent load the network will run before
loading another slave to meet demand.
Hour Offset
0 hours
The Hour Offset can be used to equalize maintenance hours of master machines on the
network. For example, if machine A has 100 hours and machine B has 25000 hours, the
Hour Offset on machine A could be set to 24900 hours so that the transfer interval
calculation would consider that the machines had equal run time.

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Figure 15: Programmable IO Settings Screen
3.6 AirSmart System Operation
This section provides information on the operation of the AirSmart sequencing protocol. Note that
only the main features of the system are discussed and this should not be considered a full
description of the behavior.
When the system is first started, it will determine the master of the system. Any machine that is
enabled and has a system pressure transducer assigned is capable of being a master. The
machine with the largest capacity that is master-capable will always become the master of the
system. If multiple master-capable machines have the same Capacity setting, the one with the
lowest Unit Number will become the master. Once the master has been decided, it will be
automatically rotated to other machines based on the following conditions:
1. A new master-capable machine with larger capacity comes online.
2. The run hours of the master machine exceeds the run hours of a slave machine of equal
capacity by more than the Transfer Interval setting. (Note that the Hours Offset setting is also
taken into account.)
The master machine will begin running and producing air when the system pressure falls below
the Load Pressure setpoint. After loading, it will accelerate to try to maintain the system pressure
at the target pressure. Other machines will be brought on and off load according to the rules
below:
1. If there are slaves available to run that are not loaded, the master will keep the system
running at or below the Transfer Load Increment percent load. All of the variable speed
machines will run off of the master’s speed command. If the system falls below the Load
Pressure setpoint, the master will command the next slave unit to load. If needed, more
machines will be asked to load, waiting Transfer Interval seconds between each machine. If

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all slaves are loaded, the master will allow the system to run up to 100% load to maintain the
target pressure.
2. If the master and one or more slaves are running, the master will keep the system running at
or above the Transfer Load Decrement percent load. If the system pressure rises above the
Unload Pressure setpoint, the master will command one slave to unload. If needed, more
machines will be commanded to unload, waiting Transfer Interval seconds between each
command. If all slaves are unloaded (only the master is running), the master will run down to
its minimum speed to attempt to maintain the target pressure. If the master is running at
minimum speed and the system pressure rises above the unload pressure, the master will
unload.
Note that only variable speed machines can accept a speed command from the master. Also, a
fixed speed master cannot send a speed command other than 100% to slave machines. If there
are any variable speed machines on the network, the system will operate most efficiently if the
largest variable speed machine is the master of the group.
3.7 AirSmart Sequencing Diagnostics
The Sequencing Diagnostics page can be found by going to Menu, then selecting Diagnostics, then
Sequencing as shown in Figure 16 below. This page shows the status of the network and each
individual compressor.
Figure 16: AirSmart Sequencing Diagnostics Menu Navigation
The information on the Sequencing Diagnostics page for AirSmart mode is shown in Figure 17
below. This page gives an overview of the sequencing operation for the network. The compressor
name, run hours, capacity, and operating pressure is also shown at the top of this page. As more