LAARS M4-Ext - Installation Manual - Manual (Page 16)

Page 16 LAARS Heating Systems
RESET MODE
•
When All-On is selected, the M4 will turn all boilers On to a 100% when System reads Short or Open and Outdoor is below
Outdoor Cutoff. When Outdoor reads Short or Open, the M4 will turn all boilers On to a 100%.
• When All-Off is selected, the M4 will turn all boilers Off when either System or Outdoor sensor reads Short or Open.
SET POINT MODE
•
When All-On is selected, the M4 will turn all boilers On to a 100% when the System sensor reads Short or Open.
• When All-Off is selected, the M4 will turn all boilers Off when the System sensor reads Short or Open.
• The Outdoor Sensor Short or Open status will not affect the control operation in Set Point mode.
OPERATING SETTINGS
PROGRAM CHANGE SETTINGS
To be able to change the M4 settings the Program/Run Switch must be set to Program. The
switch is located under the Enclosure Wiring Cover for security. The Enclosure Wiring Cover
can be securely closed using a lock.
RUN PROGRAM RUN PROGRAM
BACK SAVE
------------- SEASON --------------
Winter
Summer
CAUTION
DO NOT turn power off to the
M4 when heating season is
over. If you do so, the battery
will run down and will have to
be replaced. Instead switch to
Summer.
SEASON
Winter, Summer Default: Winter
Button: MENU/Season
•
The M4 will turn all boiler relays off when it is in Summer setting. However, a DHW
call will bring boilers back on if needed. The Message Display Line will display Summer
to show status.
• When in Winter, the M4 will activate the Sys relay whenever the Outdoor temperature
(OD) falls to or below the Outdoor Cutoff setting. In addition, it will begin heating
whenever the System temperature (SYS) falls below the Set Point Temperature. The
Message Display Line will not display any season information when in Winter.
• When the heating season is over, it is a good practice to switch the M4 to Summer
setting. This will allow DHW calls to operate the boilers when needed.
SET POINT
Adjustable 70ºF - 250ºF Default: 70ºF
Button: MENU/Set Point
•
The Set point is the temperature value the M4 will use to control the system.
• The M4 will increase, decrease or hold the modulation of the boilers to maintain the
system temperature around the Set point.
• The system can be expected to fluctuate around the set point. The amount of fluctuation
depends on the Modulation Mode, System Settings, and Stage Settings.
• If the EMS Mode was Enabled, the Set Point will be set by the EMS/BMS system and
will be available to be read but not changed on the display.
BACK SAVE
------------ SET POINT ----------
70
F
[]
RESET RATIO
Adjustable 1.00ºOD : 4.00ºSys to 4.00ºOD : 1.00ºSys Default: 1.00ºOD : 1.00ºSys
Button: MENU/Set Point
•
The Reset Ratio determines how the System water temperature (SYS) will vary with
Outside temperature (OD). With any of the ratios, the colder it becomes outside,
the hotter the temperature of the system water. The ratios are adjustable from 1.00
(OD):4.00 (SYS) to 4.00 (OD):1.00 (SYS). (See Understanding Operation Concept on
page 5)
• With a 1.00 (OD):4.00 (SYS) ratio, the System water temperature (SYS) will increase
rapidly as the outside temperature falls, hitting the maximum of 240°F at 24°F outside
temperature. With a 4.00 (OD):1.00 (SYS) ratio, the System water temperature (SYS)
will increase slowly as the outside temperature falls. Even at -30°F, the system water
will only be 125°F, and at 24°F outside, the system water will be 112°F. Such a low
Reset Ratio might be used with radiant floor heating applications.
--------- RESET RATIO ----------
1.00 OD=4.00 Sys
1.00 OD=3.00 Sys
1.00 OD=2.00 Sys
1.00 OD=1.50 Sys
1.00 OD=1.25 Sys
1.00 OD=1.00 Sys
1.25 OD=1.00 Sys
1.50 OD=1.00 Sys
2.00 OD=1.00 Sys
3.00 OD=1.00 Sys
4.00 OD=1.00 Sys
BACK SAVE