LAARS M4-Ext - Installation Manual - Manual (Page 4)

Page 4 LAARS Heating Systems
M4 OVERVIEW
SEQUENCES UP TO 4 FULLY MODULATING STAGES.
The M4 is the perfect control whenever multiple fully modulating stages are required for hydronic heating applications. The M4 controls
the on/off and the modulation of each stage to maintain precise system set point control.
PID TYPE LOGIC
The M4’s control algorithms allow it to look at the rate of change in the system. If the system temperature is changing quickly, the M4
will react quickly to adjust the modulating stages’ output. If the system temperature changes slowly, the M4 will make slow and gradual
output adjustments. Therefore, the M4 adapts to specific system requirements and minimizes fluctuations around the set point.
CONTROLS 0-10 V, 0-5 V, 2-10V, 1-5V, OR 4-20 MA MODULATING MOTORS
The M4 is designed to accurately control the output from 0 to 100% of modulation for each of these different types of motors. One M4
can even control a variety of the above different motors.
ONLY ONE SENSOR
When Set Point sensor type is selected, the M4 requires only one sensor located in the common output header of all stages. However,
when Reset is selected, an additional Outdoor Sensor is required for Outdoor Reset Ratio input.
DIGITAL DISPLAY OF ALL SYSTEM SETTINGS
The M4’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 first stage to be activated on a call for output promotes even wear on each stage. The M4 has three modes of rotation: Manual,
Last On, or Time. The Time rotates the lead stage every selected time period from every hour to every 60 days.
OUTDOOR RESET
The M4 has a hydronic outdoor temperature reset function. This allows the M4 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.
STANDBY BOILERS
Each of the M4 stages can be configured as a Standby boiler with an adjustable Standby delay. A boiler can be used as a backup during
extended large demand periods.
SYSTEM OUTPUT
In Set Point mode, 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. In Outdoor Reset mode, the System Output will activate 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.
STAGING (NORMAL) OR PARALLEL MODULATION
The M4 can stage boilers as needed. That will allow it to increase the modulation on the lead boiler. When the lead boiler reaches its
modulation start point adjustment and does not satisfy the load, the M4 will start the next boiler and so on... Moreover, the M4 allows
for a parallel mode that can modulate several boilers together as a one large boiler. This mode is useful for boilers with lower water
content, which are usually more efficient at lower firing points.
ADD UP TO 16 BOILER STAGE (OPTIONAL)
As a stand-alone, the M4 is designed to control four modulating boilers. However, it has the capability of expanding its control to two
extension panels each with six boiler stages. Thus, the M4 can control a total of up to 16 boiler stages.