Submittal

LAARS M4-LHS
Control for
Condensing,
Non-Condensing,
Modulation and
Stage-Fired Boilers
CA009200
Submittal Data
Date:
Project #:
Engineer:
Prepared By:
Bid Date:
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Features
• Operates two groups of boilers -
condensing and non-condensing -
each with independent configura-
tion - to achieve the highest
system efficiency
• Chooses condensing or non-
condensing groups based on
system temperature
• Controller works with either stage-
fired or modulated boilers
• Controls 0-5V, 1-5V, 0-10V, 2-10V
and 4-20mA boilers, or stage-fired
boilers, in any combination
• Lo/Hi/Lo/Hi sequencing fires lag
boiler after the lead boiler reaches
full fire capacity - Lo/Lo/Hi/Hi
sequencing provides an opportu-
nity for higher boiler efficiency to
bring on the lowest firings stages
of all the boiler before moving any
of them to higher firing rates
• Parallel or normal modulation
provides efficient, smooth, and
adjustable modulation that can fit
most applications whether the
boilers are to sequence normally
(one after another) or in parallel
• Each boiler can be set for one of
three rotation modes; timed (one
hour to sixty days), manual, or
last-on/last-off
• Each boiler can be set individually
to be automatically operated, fully
on, manually adjusted, off or be
considered a standby boiler. The
standby boiler is used as a
backup with an adjustable standby
delay. This feature is great for
using less efficient boilers (with
lower initial purchase cost) for
periods of high demand only
• Soft-off feature, lag delay and last
stage hold assist in minimizing
boiler short-cycling
• Adjustable ignition start point and
modulation start point
• Adjustable purge delay feature to
match the boiler's pre-purge time
• Adjustable minimum and maxi-
mum system temperature protect
boilers or system
• Communicates with EMS (energy
management system) by adding
the XSIG 4-20mA interface
module, and has shutdown and
prove inputs for the EMS
• Domestic hot water with or without
priority
• Outdoor reset allows the controller
to adjust system water tempera-
ture based on outdoor air
temperature for fuel savings
• Built-in day/night schedule with
adjustable night setback for fuel
savings
• External setback signal is accepted
for applications that do not follow a
pre-detemined schedule
• Summer shutdown with domestic
water override
• Brightly lit LCD, visible with no
ambient light
• Graphics that display in plain English
• Graphical history displayed on the
screen shows system and outdoor
temps for last 24 hours
• Settings can be copied from one
boiler to another for easy program-
ming
• Memory and backup with lithium
battery to store information for 100
days
• Locking NEMA-1 enclosure -
controller has an integral program-
ming switch that can only be
accessed when wiring cover has
been unlocked and removed
• UL Listed, tested per standard 916
Standard
Equipment
• Multiple boiler control, used to
lead-lag modulating, stage-fired,
condensing and non-condensing
boilers
• Controls up to four stages (one
modulating boiler is one stage)
• Ready to use with Laars X-BAC
BACnet interface module
• Ready to use with up to two
M4EXT extension modules for
control of up to 16 modulating
stages
• Ready to use with XSIG module to
accept external 4-20mA control
signal
• Outdoor reset or setpoint control
• System water temperature sensor
• System water temperature sensor
well
• Outdoor air temperature sensor
• Outdoor air temperature sensor clip
®