LAARS S8Ext - Installation Manual - Manual (Page 18)

Page 18 LAARS Heating Systems
BURNER TYPE
On/Off, 2-Stage, 3-Stage, 4-Stage Default: On/Off
Button: MENU/<System Startup>/..../Burner Type
• The S8 can sequence from a single stage and up to four stages per heating or cooling
unit.
--- BURNER TYPE ----
On/Off
2-Stage
3-Stage
4-Stage
BACK SAVE
BOILER OUTPUT
None, Pump, Valve Default: None
Button: MENU/<System Startup>/..../Boiler Output
• When None is selected, the S8 will sequence multiple heating or cooling units without
any additional unit pumps or valves.
• The Pump option allows the S8 to control the cooling or heating unit stages in addition
to the unit pumps. The stage pump will run for the Run-On delay after the lower stage of
that unit has de-energized.
-- BOILER OUTPUT --
None
Pump
Valve
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• The Valve optional functions similar to the pump option except that when all stages are off and after Run-On delay has elapsed,
the Lead unit's valve relay will remain energized to allow for pump flow across the system. The lead unit's valve will remain
energized until the Outdoor temperature rises above the Outdoor Cutoff or when the Shutdown, or Summer is activated.
TOTAL BOILERS
1 to 24 Default: varies based on Burner Type and Boiler Output
Button: MENU/<System Startup>/..../Boiler Output
• This option in combination with Burner Type and Boiler Output Startup options will
determine the total number of outputs the S8 will need to control.
• If more stages are selected than the S8 and S8 Extension has, the extra stages will have
CE as their status.
-- TOTAL BOILERS --
8
[ ]
BACK SAVE
STAGING
Multiple Outputs, Single Output Default: Multiple Outputs
Button: MENU/<System Startup>/..../Staging
• Most units will require that the higher output stages to be energized after the lower output
stages. These units will need to select the Multiple Output option. That means, both
Low and High Output stages must be energized for the unit to function.
• Some units require that when the higher output stages are required, the lower stages must
de-energize. To operate these units, the user must select the Single Output option.
------ STAGING ------
Multiple Outputs
Single Output
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SEQUENCE
Lo/Hi/Lo/Hi, Lo/Lo/Hi/Hi Default: Lo/Hi/Lo/Hi
Button: MENU/<System Startup>/..../Sequencing
• Some units run more efficient when the lower stages are energized alone than with
the higher stages. These types of units should select Lo/Lo/Hi/Hi. Then, the S8 will
sequence the lower stages of all Automatic units before sequencing the higher stages.
------ SEQUENCE -------
Lo/Hi/Lo/Hi
Lo/Lo/Hi/Hi
BACK SAVE
• For
stage of the same unit. Then when more stages are needed, it will fire the lower stage of the lag unit followed by the higher
stage of the lag unit.
CONTROL LOGIC
PID, OSS (Over-Sized-System) Default: PID
Button: MENU/<System Startup>/..../Sequencing
• The PID option allows the S8 to sequence stages based on Reaction Time and Boiler Min
Run Time. The PID relies on the rate of change in the System Temperature. The PID
logarithmic calculations foresee changes and sequence stages based on those changes. It
is the most efficient operation for most heating and cooling applications.
--- CONTROL LOGIC---
PID
OSS
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