LAARS M4-LHS - Installation Manual - Manual (Page 8)

HT# 059295-00
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M4-LHS installation and Operation Manual
FEaTurES
Laars designed the M4-LHS with Hydronic building heating, using both condensing and non-condensing boilers, as the primary purpose.
In addition, the M4-LHS is capable of controlling modulating and staging boilers. With this in mind, many of the M4-LHS features can
be utilized to ease, enhance, and improve your system performance.
Condensing and Non-Condensing Boilers Can be Modulating or Multi-Stage.
The M4-LHS can operate both modulating and staging boilers. Just specify each of the Condensing and Non-Condensing boiler group
type and the M4-LHS activates the groups based on an adjustable set of criteria.
PiD Type Logic
The M4-LHS's control algorithms allow it to look at the rate of change in the system. If the system temperature is changing quickly,
the M4-LHS reacts quickly to adjust the modulating stages’ output. If the system temperature changes slowly, the M4-LHS shall make
slow and gradual output adjustments. Therefore, the M4-LHS adapts to specific system requirements and minimizes fluctuations around
the set point.
Controls 0-10 V or 4-20 ma modulating Burners
Whenever any of the Condensing or Non-Condensing group type is set to Modulating, the M4-LHS accurately controls the output from
0 to 100% of modulation for each of these different types of motors. Moreover, a single M4-LHS can control multiple modulating burners
each with a different modulating signal.
Controls On/Off, 2-Stage, 3-Stage, or 4-Stage Burners
Whenever one of the Condensing or Non-Condensing group Type is set to Staging, the M4-LHS accurately sequences the stages using
a PID logic.
Digital Display of all System Settings
The M4-LHS's alphanumeric digital display names each system parameter in simple English and shows its precise value. The easy
to follow menu system allows users to quickly make changes to any system setting without having to learn any specialized codes or
keyboard commands.
automatic rotation among Stages
Rotating the lead stage of each group promotes even wear. The M4-LHS has three modes of rotation: Manual, Last On, or Time. The
Time rotates the lead stage every selected period from every hour to every 60 days.
Outdoor reset or Set Point
The M4-LHS has a hydronic outdoor temperature reset function. This allows the M4-LHS to change the set point based on outdoor
temperature. Furthermore, additional settings have been added to fine tune this operation, like Offset, Minimum, and Maximum Water
Temperature and night setback schedule.
System Output
This output can be used to activate a system pump, combustion air damper, or perform any other function that is required when any stage
is active. It energizes whenever the outdoor temperature is below the Outdoor Cutoff setting. A System Prove input checks the status
of components activated by the System output before stages can be activated.
Normal or Parallel Modulation
The M4-LHS can stage modulating boilers as needed. In Normal Modulation, it increases the lead boiler modulation until it reaches
its Modulation Start percent adjustment. Then, the M4-LHS starts the next boiler and so on. Moreover, the M4-LHS offers a parallel
mode that can modulate several boilers together as a single large boiler. This mode is useful when used with condensing boilers as they
run more efficient at lower modulation. Thus, it is better to run several boilers at lower modulation than to run a single boiler at full fire.
add up to 16 Boiler Stages (Optional)
As a stand-alone, the M4-LHS is designed to control four stages. However, it has the capability of expanding its control to two extension
panels each with six boiler stages. Thus, the M4-LHS can control a total of up to 16 boiler stages.