Annunciator Purge Setup: Difference between revisions

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The annunciator Purge / Blowdown setup screen is used to set up two features:
There are two features related to unit purge:


# Low Purge Alarm
# Low Purge Alarm
# High blowdown limit / alarm
# Automated purge sequence


The setup page is shown below. To reach this page, while in "Engineering" access mode navigate to "Annunciator Setup" -> "Outputs Setup" -> "Purge / Blowdown Limits".
Note that either auto-crank or an ECU is needed for these features


Note that neither of these functions will work if autostart or an ECU is not used.
=== Low Purge Alarm ===


=== Annunciator Purge / Blowdown Alarm Setup ===
[[File:Purge-limit.png|600px]]
← Controls — Brain (Annunciator)


The annunciator Purge / Blowdown setup screen is used to set up two features:
The purge alarm is used to specify a minimum suction level to allow the engine to start. In the above screenshot, this is 10 psi. If the suction is below 10 psi, starting the engine will always go directly to FAULTED. If unused, this can be set to 0.


# Low Purge Alarm
The sensor used for suction does not have to be specified- the system will find the analog input with the name "Suction", "Suction Stg 1", etc.
# High blowdown limit / alarm


The setup page is shown below. To reach this page, while in "Engineering" access mode navigate to "Annunciator Setup" -> "Outputs Setup" -> "Purge / Blowdown Limits".
=== Purge Sequence Setup ===


Note that neither of these functions will work if autostart or an ECU is not used.
The purge sequence can be used to automatically purge the engine on startup. It requires the presence of a system-controlled suction, bypass, and blowdown valve. The suction valve can be set up as a suction block valve or a proportional suction PID loop. The setup is found at “Settings” -> “Brain” -> “Outputs Setup” -> “Purge Sequence Setup”. The general sequence is:


''Purge Setup Sreeen''
#Blowdown, bypass, and suction are closed
#Blowdown opened; suction opened (slowly if possible)
#Bypass opened
#Blowdown and suction closed


=== Purge Alarm Setup ===
There are a variety of detailed settings in the sequence, see the setup page for more information.
The purge alarm is used to specify a minimum suction level to allow the engine to start. In the above screenshot, this is 10 psi. If the suction is below 10 psi, starting the engine will always go directly to FAULTED. If unused, this can be set to 0.
The sensor used for suction does not have to be specified- the EIM will find the analog input with the name "Suction", "Suction Stg 1", etc.


=== Blowdown Limit Setup ===
The purge sequence will not actually be entered unless the “Low Purge Alarm” mentioned above is set to something other than zero. If the suction is below the setting at startup, the purge sequence will run before pre lube.
The blowdown limit can be specified, in PSI, that signifies the maximum psi permissible on suction before the engine will continue the start sequence. If used, set this value to something other than zero.
During startup, if a blowdown valve is specified in the valve setup screen, it will be opened if above the "High Blowdown Limit" and until it is below that limit. If the amount of time in "Blowdown max time" passes and the suction pressure is still above the limit, the system will fault out.
Note that if no blowdown valve is present in the system this function can still be used (with a "max time" of 1 second) to fault-out if the system is pressurized on startup.

Latest revision as of 22:22, 4 August 2022

There are two features related to unit purge:

  1. Low Purge Alarm
  2. Automated purge sequence

Note that either auto-crank or an ECU is needed for these features

Low Purge Alarm

Purge-limit.png

The purge alarm is used to specify a minimum suction level to allow the engine to start. In the above screenshot, this is 10 psi. If the suction is below 10 psi, starting the engine will always go directly to FAULTED. If unused, this can be set to 0.

The sensor used for suction does not have to be specified- the system will find the analog input with the name "Suction", "Suction Stg 1", etc.

Purge Sequence Setup

The purge sequence can be used to automatically purge the engine on startup. It requires the presence of a system-controlled suction, bypass, and blowdown valve. The suction valve can be set up as a suction block valve or a proportional suction PID loop. The setup is found at “Settings” -> “Brain” -> “Outputs Setup” -> “Purge Sequence Setup”. The general sequence is:

  1. Blowdown, bypass, and suction are closed
  2. Blowdown opened; suction opened (slowly if possible)
  3. Bypass opened
  4. Blowdown and suction closed

There are a variety of detailed settings in the sequence, see the setup page for more information.

The purge sequence will not actually be entered unless the “Low Purge Alarm” mentioned above is set to something other than zero. If the suction is below the setting at startup, the purge sequence will run before pre lube.