Make sure you have the right control, Initial setup, Selecting the system features – LAARS M4-Ext - Installation Manual User Manual
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MAkE SURE YOU HAvE THE RigHT CONTROL
If you need the M4-CNC to do additional tasks that either are not listed or do not know how to configure them, contact Laars.
iNiTiAL SETUP
Setting an Initial Program will ease the configuration of the M4-CNC and will give the opportunity to utilize many of the energy saving
features and give more comfortable heat when needed.
The program should consist of the following:
• Selecting the features that your system can utilize.
• Installation: Install the Control, switches and sensors. See "Installation" on page 9
• Setting the System Startup. See "Startup Settings" on page 16
• Setting the System Operating Settings. See "Operating Settings" on page 22
• Adjusting Reset Ratio and Water Offset (In Reset Mode Only). See "Reset Ratio" on page 22
SELECTiNg THE SYSTEM FEATURES
The M4-CNC has been designed with Hydronic building heating, using both condensing and non-condensing boilers, as the primary
purpose. With this in mind, many of the M4-CNC features can be utilized to ease, enhance, and improve your system performance.
Some of these features are listed in this section.
NUMBER OF STAgES FOR EACH gROUP OF BOiLERS
• The M4-CNC can be configured to control up to 4 condensing and non-condensing boilers. It can control up to 16 boiler stages using
a maximum of two M4-Extension Panels (CA004400).
MOdULATiON MOdE
• The M4-CNC can stage modulating boilers using one of two methods. Normal Modulation Mode, allows it to increase the modulation
of the lead boiler. When the lead boiler reaches its Modulation Start point adjustment and does not satisfy the load, the M4-CNC will
start the next boiler and so on. This mode targets boilers that can run more efficient at higher modulation rates.
• The Parallel Modulation Mode can modulate several boilers together as one large boiler. This mode is useful for boilers that are
more efficient at lower firing rate as in many condensing boilers.
MOdULATiNg SigNAL
• The M4-CNC is designed to accurately control the modulation output from 0 to 100% for either current (4-20mA) or voltage (0-5V,
0-1V, 1-5V, 2-10V) motors. A single M4-CNC can control a combination of the above modulation motors.
AUTOMATiC ROTATiON AMONg BOiLERS
• Rotating the first burner to be activated on a call for output promotes even wear on all burners. The M4-CNC has three modes of
rotation: Manual, Last-ON, or Time; automatically rotating every selected time period from every hour to every 60 days.
SETBACk OR dAY/NigHT SCHEdULiNg
Two Setback modes are available for the M4-CNC:
• The Day/Night Scheduling provides an adjustable time-based schedule for the Setback (only available when Shutdown or Tstat is
selected as the Setback/Shutdown Startup option). See "Shutdown/Tstat/Setback Mode" on page 19.
• The Setback mode uses an external signal to switch the operation of the M4-CNC in and out of setback mode.
SYSTEM RUN-ON
• This feature lets the M4-CNC run the SYS relay for a longer period after the boilers have been turned off. When this relay is used to
control a pump, it helps in dissipating the excess heat from the boilers combustion chamber.
LAARS Heating Systems
HT# 059104-00 B