Piping and wiring diagrams, Hybrid piping diagram, System – LAARS M4-LHS - Installation Manual User Manual
Page 51: M4-lhs installation and operation manual, Ma gnd vlt, Gnd vlt, Ma temp outdoor o o temp system extension module, Prove /dhw shutdown /setback /tstat

HT# 059295-00
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M4-LHS installation and Operation Manual
SYSTEM
A
B
C
D
1 2
RUN
PROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
3 4 5 6 7 8 9 10 11 12
13
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30 31
L N
-
+
+
T
T
O
O
RS-485
mA
GND
VLT
SYS
A
B
C
D
PWR
CUR / VLT
A
-
+
+
mA
GND
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
/TSTAT
M4-LHS
HYBRID CONTROL
Boiler 4
Non-Condensing
On/Off
System
Sensor
120VAC
Building Heating Loop
Boiler 1
Condensing
Modulating
Boiler 2
Boiler 3
Non-Condensing
On/Off
Condensing
Modulating
Outdoor
Sensor
PiPiNg aND WiriNg DiagraMS
HYBriD PiPiNg DiagraM
System:
The M4-LHS operates two modulating boilers and two On/Off Boilers. The boilers are piped in Reverse Return on the
primary loop. The System output is controlling the System Pump.
Laars is aware that each installation is unique. Thus, Laars is not responsible for any installation related to any electrical
or plumbing diagram generated by Laars . The provided illustrations are to demonstrate Laars ’s control operating concept
only.
STarTuP SETTiNgS
Boiler Type = Hybrid
Condensing Boiler Type = Modulating
Condensing Boiler Number = 2
Condensing Modulating Mode = Parallel
Non-Condensing Boiler Type = Staging
Non-Condensing Output Type = On/Off
Non-Condensing Boiler Number = 2
Two Modulating
Condensing Boilers
and Two On/Off Non-
Condensing Boilers