LAARS M4-LHS Installation Manual
Installation and Operation Manual
Modulating and Condensing /
Document 4232
M4-LHS
Non-condensing Boiler control
Hybrid Multi-Boiler Control
WARNING
FOR YOUR SAFETY: This product must be installed and serviced by
a professional service technician, qualified in hot water heater/boiler
controls installation and maintenance. This manual is intended for
anyone who will install, operate or maintain the control system. Before
you begin installation and operation of this control, it is important that
you thoroughly review this manual. Improper installation and operation
could result in damage to equipment and possibly even personal
injury. Laars Controls are not intended for use as operation safety limit
controls. Another control, that is intended and certified as a high limit
control, must be in the water heater/boiler control circuit.
HTC# 059295-00 A
Contents
Hybrid Logic Overview
. . . . . . . . . . . . . . . . . . 3
Modulating Logic Overview. . . . . . . . . . . . . . . . 4
Outdoor Reset Concept . . . . . . . . . . . . . . . . . . 5
Control Layout . . . . . . . . . . . . . . . . . . . . . . . 6
Extension Layout . . . . . . . . . . . . . . . . . . . . . . 7
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Make Sure You Have the Right Control . . . . . . . . . 9
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 10
Mounting the Enclosure. . . . . . . . . . . . . . . . . 10
Install the Sensors . . . . . . . . . . . . . . . . . . . . 11
System Sensor Installation . . . . . . . . . . . . . . . . 11
Outdoor Sensor Installation . . . . . . . . . . . . . . . . 11
Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Wiring the Power . . . . . . . . . . . . . . . . . . . . . 12
Wiring the Sensors . . . . . . . . . . . . . . . . . . . . 12
Wiring the Shutdown, Tstat, or Setback . . . . . . . . . . 12
Wiring the Prove . . . . . . . . . . . . . . . . . . . . . 13
Wiring the Indirect Domestic Hot Water (DHW) Call . . . . 13
Wiring the System Output. . . . . . . . . . . . . . . . . 13
Wiring the Boilers. . . . . . . . . . . . . . . . . . . . . 14
Wiring Boiler Activation or On/Off Staging Boilers . . . . . 14
Wiring Multi-Stage Boilers . . . . . . . . . . . . . . . . 14
Wiring to Modulating Boilers . . . . . . . . . . . . . . . 14
Wiring the 4-20mA Modulating Boilers . . . . . . . . . . 14
Wiring Voltage Modulating Boilers. . . . . . . . . . . . . 14
Connecting to the Extensions and 4-20mA EMS Interface 15
Connecting to BACnet Interface Module . . . . . . . . . 16
Activate the Battery . . . . . . . . . . . . . . . . . . . 16
HYBRID Startup Menu . . . . . . . . . . . . . . . . . . 17
Modulating Startup Menu . . . . . . . . . . . . . . . . 18
Startup Settings. . . . . . . . . . . . . . . . . . . . . . 19
Program Change Switch Setting . . . . . . . . . . . . . 19
Startup Sequence . . . . . . . . . . . . . . . . . . . . 19
Boiler Type . . . . . . . . . . . . . . . . . . . . . . . . 19
Sensor Type . . . . . . . . . . . . . . . . . . . . . . . 19
EMS Input Mode . . . . . . . . . . . . . . . . . . . . . 19
EMS 4mA and 20mA Set Points. . . . . . . . . . . . . . 20
HYBRID Startup Settings . . . . . . . . . . . . . . . . 20
Switch Set Point . . . . . . . . . . . . . . . . . . . . . 20
Switch Differential . . . . . . . . . . . . . . . . . . . . 20
Switch Delay . . . . . . . . . . . . . . . . . . . . . . . 21
Heavy Load Sequence 2nd Group . . . . . . . . . . . . 21
Condensing and Non-Condensing Boiler Type . . . . . . 21
Condensing and Non-Condensing Boiler Number . . . . . 21
HYBRID Modulating Boiler Settings . . . . . . . . . . 22
Modulating Output Type . . . . . . . . . . . . . . . . . 22
Modulating Mode . . . . . . . . . . . . . . . . . . . . . 22
HYBRID Staging Boiler Settings . . . . . . . . . . . . 22
Staging Output Type . . . . . . . . . . . . . . . . . . . 22
Staging Mode . . . . . . . . . . . . . . . . . . . . . . 22
Modulating Boiler Settings . . . . . . . . . . . . . . . 23
Boiler Number . . . . . . . . . . . . . . . . . . . . . . 23
Modulating Output Type . . . . . . . . . . . . . . . . . 23
Modulating Mode . . . . . . . . . . . . . . . . . . . . . 23
Startup Settings (Continued) . . . . . . . . . . . . . . 24
Prove/Indirect Domestic Hot Water (DHW) Priority . . . . 24
Indirect Domestic Hot Water Set Point . . . . . . . . . . 24
Shutdown/Tstat/Setback Mode . . . . . . . . . . . . . . 24
Boost Mode . . . . . . . . . . . . . . . . . . . . . . . 25
Sensor Fault . . . . . . . . . . . . . . . . . . . . . . . 25
Setting the Control to Factory Defaults . . . . . . . . 25
BACnet MSTP Communication Menu. . . . . . . . . 26
BACnet Mode . . . . . . . . . . . . . . . . . . . . . . 26
BACnet Baud Rate . . . . . . . . . . . . . . . . . . . . 26
MS/TP Address. . . . . . . . . . . . . . . . . . . . . . 26
BACnet ID . . . . . . . . . . . . . . . . . . . . . . . . 26
Operating Settings . . . . . . . . . . . . . . . . . . . . 27
Program Change Switch Setting . . . . . . . . . . . . . 27
Season. . . . . . . . . . . . . . . . . . . . . . . . . . 27
Set Point . . . . . . . . . . . . . . . . . . . . . . . . . 27
Reset Ratio. . . . . . . . . . . . . . . . . . . . . . . . 27
Offset . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Outdoor Cutoff Temperature . . . . . . . . . . . . . . . 30
Minimum Water Temp . . . . . . . . . . . . . . . . . . 30
Maximum Water Temp . . . . . . . . . . . . . . . . . . 30
HYBRID Operating Menu . . . . . . . . . . . . . . . . 28
Modulating Operating Menu . . . . . . . . . . . . . . 29
System Settings . . . . . . . . . . . . . . . . . . . . . 31
Setback . . . . . . . . . . . . . . . . . . . . . . . . . 31
Purge Delay . . . . . . . . . . . . . . . . . . . . . . . 31
System Run-On . . . . . . . . . . . . . . . . . . . . . 31
Lead Boiler Rotation . . . . . . . . . . . . . . . . . . . 32
Standby Time. . . . . . . . . . . . . . . . . . . . . . . 32
Last Stage Hold . . . . . . . . . . . . . . . . . . . . . 32
Lead Stages . . . . . . . . . . . . . . . . . . . . . . . 32
Modulating Boiler Operating Settings . . . . . . . . . 33
Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Lag Delay . . . . . . . . . . . . . . . . . . . . . . . . 33
Soft-Off Delay . . . . . . . . . . . . . . . . . . . . . . 33
Staging Boiler Operating Settings . . . . . . . . . . . 34
Reaction Time . . . . . . . . . . . . . . . . . . . . . . 34
Minimum Runtime . . . . . . . . . . . . . . . . . . . . 34
Day - Night Schedule . . . . . . . . . . . . . . . . . . 36
Set Time . . . . . . . . . . . . . . . . . . . . . . . . . 36
Maintenance . . . . . . . . . . . . . . . . . . . . . . . 36
System & Outdoor Sensor Trim . . . . . . . . . . . . . . 36
Output Modulation Trim. . . . . . . . . . . . . . . . . . 37
Conguration . . . . . . . . . . . . . . . . . . . . . . . 37
Display . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Boiler Status . . . . . . . . . . . . . . . . . . . . . . . 38
Display Modulating Boiler Status . . . . . . . . . . . . . 38
Display Messages . . . . . . . . . . . . . . . . . . . . 38
Boiler Stage Menu . . . . . . . . . . . . . . . . . . . . 38
Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Ignition % . . . . . . . . . . . . . . . . . . . . . . . . 40
Modulation Start % . . . . . . . . . . . . . . . . . . . . 40
Copy Settings - Boiler A Only . . . . . . . . . . . . . . . 40
Troubleshooting . . . . . . . . . . . . . . . . . . . . . 41
Specications . . . . . . . . . . . . . . . . . . . . . . . 43
Hybrid - Outdoor Reset - BACnet Variable list . . . 44
Modulation - Outdoor Reset - BACnet Variable list 45
Modulation - Set Point - BACnet Variable list . . . . 46
BACnet PICS Statement. . . . . . . . . . . . . . . . . 47
Piping and Wiring Diagrams . . . . . . . . . . . . . . 48
Hybrid Piping Diagram . . . . . . . . . . . . . . . . . 48
Hybrid Wiring Diagram . . . . . . . . . . . . . . . . . 49
Modulating Piping Diagram. . . . . . . . . . . . . . . 50
Modulating Wiring Diagram. . . . . . . . . . . . . . . 51
HT# 059295-00 A
2
M4-LHS Installation and Operation Manual
HYBRID LOGIC OVERVIEW
In response to new advancement in condensing boiler design and size, many applications utilize multiple condensing boilers in
addition to the non-condensing boilers. That triggered Laars's design of the M4-LHS. It is intended to manage the two groups of
When Hybrid is selected
as the Boiler Type, the M4-LHS will select the lead group based on the Target temperature switching set point. See "Switch Set
Point" on page 20. The Condensing group of boilers will be the Lead group when the System Temperature is below the System Target
Switching Set Point. However, when the System Temperature rises above the Switching Set Point, the Non-Condensing boiler group
will be the lead group and the Condensing Group will be the lag group.
Basically, the M4-LHS will allow the condensing group of boilers to operate as along as the System sensor is below the Switching Set
Point. See"Switch Set Point" on page 20. During that period, if additional output boilers are needed, the M4-LHS may energize the
Non-Condensing boilers to meet the load depending on the Heavy Load Sequence 2nd Group setting. See"Heavy Load Sequence 2nd
Group" on page 21. When less output is required the M4-LHS will de-energize the lag group of boilers prior to de-energizing the lead
group of boilers.
To eliminate any short-cycling due to rapid changes in the Target Temperature used in the switching, an adjustable Switching Delay
has been incorporated. See"Switch Delay" on page 21.
Each of the condensing and non-condensing groups of boilers can be either modulating or staging. Modulating boilers can be of
4-20mA modulating signal or 0-10V modulating signal. See "Modulating Output Type" on page 23. Staging boilers can be On/Off,
2-Staeg, 3-Stage, or 4-Stage. See "Staging Output Type" on page 22.
For Hybrid settings, See "Boiler Type" on page 19.
To set the Condensing and Non-Condensing boiler types See "HYBRID Modulating Boiler Settings" on page 22.
System
Temp
140°F
120°F
100°F
SWITCH MODE = Target Temperature
SYSTEM
o
o
OD=
F SYS=
F
25
145
A
B
<<A>> B
100% 52%
C
NONCOND
NONCOND
NONCOND
CONDCOND
CONDCOND
NONCOND
D
RUNPROGRAM
B
C
A
S
D
WR
B
C
A
SY
P
/ VLT
CUR / VLT
CU
CUR / VLT
R
m
mAGND
V
mAGND
A
V
GND
LT
LT
L
N
-
-
+
+
+
+
+
5
19
2
15
3
0
18
6
13
910
16
78
1
17
4
11
12
2
14
Target Switch
Set Point
SYSTEM
A
B
C
D
RUNPROGRAM
C
A
B
A
D
WR
SYS
B
C
P
V
T
R
V
U
/
L
CUR
R / VLT
/
CU
C
AGND
mAGND
mAGND
VLT
VLT
m
LN
-
-
+
+
+
+
5
13
9
15
3
19
20
18
6
78
16
10
4
17
11
12
14
1
2
Above the Switch Set Point
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
N
SHUTDOW
N
N
SIO
E
XTE
PROVE
OUTDOOR
SYSTEM
D
TS
TAT
/
/DHW
E
MODUL
TE
MP
TEMP
CUR / VLT
K
A
E
C
TB
/S
AGND
A
V
V
LT
LT
m
m
-485
RS
TO
O
O
O
T
+
+
+
+
2
9
30
28
31
32
26
25
23
22
24
27
21
Non-Condensing are the Lead Group
Condensing are the Lag Group
= 120°F
o
o
OD=
F SYS=
F
25
145
<<A>> B
100% 52%
Below the Switch Set Point
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
OWN
S
HUTD
EXTENSION
VE
PRO
M
ST
OUTDOOR
S
E
Y
D
/TSTAT
/DHW
MODULE
T
TEMP
EMP
LT
CUR / VLT
/SETBACK
AGND
A
VLT
m
m
VLT
S
-485
R
O
O
O
O
T
T
++
+
+
+
6
32
23
2
28
29
3031
25
21
22
24
27
Condensing are the Lead Group
Non-Condensing are the Lag Group
M4-LHS Installation and Operation Manual
HT# 059295-00 A
3
MODULATING LOGIC OVERVIEW
The Modulation PID logic is capable of controlling multiple modulating current or voltage boilers. When heat is required, the control
PID activates the lead boiler and starts its purge. See "Purge Delay" on page 31. This is followed by the initiation of its modulation at
the Ignition %. See "Ignition %" on page 40. When additional heat is needed, the control starts to increase the lead boiler modulation
until the Modulation Start % has been reached. See "Modulation Start %" on page 40. Any additional heat requirement starts the lag
boiler purge. While the lag boiler is in purge, the lead boiler resumes its modulation until it reaches full re (100% modulation).
Additional heat requirements triggers the control to increase the lag boiler modulation.
When the M4-LHS PID requires reduced output, it will reduce the modulation of the lag boiler until it reaches its Ignition %. That
shall be followed by the reduction of modulation of the lead boiler until it reaches 40% percent of the Modulation Start %. This shall
trigger the control to turn off the lag boiler. The control will keep reducing the lead boiler modulation until it reaches its Ignition %.
If the Last Stage Hold was activated, the control will hold the lead boiler at the Ignition % until the System Temperature exceeds the
Target Set Point by the Last Stage hold setting. See "Last Stage Hold" on page 32.
For Modulating boilers, See "Boiler Type" on page 19. Also, See "HYBRID Modulating Boiler Settings" on page 22.
HT# 059295-00 A
4
M4-LHS Installation and Operation Manual
OUTDOOR RESET CONCEPT
Outdoor Temperature (in °F)
70 60
50
40 20
30 0 -10
10 -20
100
120
110
130
140
150
160
180
170
190
200
210
220
1:3 1:2 1:1.5
1:1.25
1:1
1.25:1
1.5:1
2:1
3:1
4:1
Water Temperature (in °F)
Reset Ratio Curves
Reset Ratio is Presented as
Outdoor Temp. : Water Temp. Ratio
1:4
The M4-LHS has multiple operating modes that satisfy most hydronic systems. It
changes the System Set Point based on outdoor temperature (Outdoor Reset). The
M4-LHS varies the temperature of the circulating heating water in response to
changes in the outdoor temperature. The heating water temperature is controlled
through the modulation or sequencing of the stages.
The M4-LHS also controls the system circulating pump with an adjustable Outdoor
Cutoff. When the outdoor temperature is above the Outdoor Cutoff, the pump
is off and no heating water is circulated through the system. When the outdoor
temperature drops below the Outdoor Cutoff, the system pump relay is activated
and the heating water circulates through the system. The temperature of the heating
water is controlled by the Reset Ratio, Water Offset, and changes with Outdoor
Temperature.
Reset Ratio/Outdoor Reset
When a building is being heated, heat escapes through the walls, doors, and windows
to the colder outside air. The colder the outside temperature, the more heat escapes.
If you can input heat into the building at the same rate that it is lost out of the
building, then the building temperatures will remain constant. The Reset Ratio is an
adjustment that lets you achieve this equilibrium between heat input and heat loss.
The starting point for most systems is the 1.00 (OD):1.00 (SYS) (Outdoor
Temperature : Heating Water Temperature) ratio. This means that for every degree
the outdoor temperature drops, the temperature of the heating water increases by one
degree. The starting point of the curves is adjustable, but comes factory selected
at 70°F Outdoor Temperature and 100°F Water Temperature. For example with
a 1.00 (OD):1.00 (SYS) ratio, if the outdoor temperature is 50°F, this means the
temperature has fallen 20° from the starting point of 70°F. Therefore, the heating
water temperature shall increase 20° to 120°F.
Each building has different heat loss characteristics. A very well insulated building
will not lose much heat to the outside air, and may need a Reset Ratio of 2.00
(OD):1.00 (SYS) (Outdoor:Water). This means the outdoor temperature would
have to drop 2° to increase the water temperature 1 degree. On the other hand, a
poorly insulated building with insufcient radiation may need a Reset Ratio of 1.00
(OD):2.00 (SYS). This means that for each degree the outdoor temperature dropped
the water temperature increases by 2°. The M4-LHS has a full range of Reset Ratios
to match any buildings heat loss characteristics.
A heating curve that relies not only on Outdoor Temperature but also on the type
of radiation improves heat comfort. The following are suggested initial settings for
different types of radiation based on average building insulation and heat loss. The
contractor can ne tune these adjustments based on the specic building need.
Type of Radiation in Building Reset Ratio Offset
Radiators (Steel & Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F
Baseboard (Finned copper tube& Cast Iron) 1.00 (OD) : 1.00 (SYS) 0˚F
Radiant (High Mass/Concrete) 4.00 (OD) : 1.00 (SYS) -10˚F
Radiant (Low Mass/Joists) 2.00 (OD) : 1.00 (SYS) -10˚F
Fan Coils & Air Handlers 1.00 (OD) : 1.00 (SYS) 20˚F
M4-LHS Installation and Operation Manual
With a 0° Offset, the
Reset curves begin at
100° Water Temperature.
With a -20° Offset, the
Reset curves begin at
80° Water Temperature.
With a +20° Offset, the
Reset curves begin at
120° Water Temperature.
130
120
110
Water T emp erature
100
70 405060
Outdoor Temperature
110
100
90
Water Tem peratur e
80
70 405060
Outdoor Temperature
150
140
130
Water Tem per ature
120
90
100
70 405060
Outdoor Temperature
1:4 1:1
4:1
1:4
-20 Offset
1:4
1:1
4:1
1:1
+20 Offset
5
4:1
HT# 059295-00 A
CONTROL LAYOUT
Program Switch to restrict access to
function changes. This switch is
covered with Wiring Enclosure.
LED indicates the
associated relay status.
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz , 30VA MAX
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
PWR
L
1
to de-energize the equipment before servicing.
SYS
N
2
3
4
A
B
C
D
5
6
7
8
9
10
11
12
The digital display shows the system status, set point,
lead stage <in brackets>, and status of each stage.
To view and adjust settings, press the appropriate buttons.
Buttons function is presented on
Bottom Row of display.
M4-LHS
SYSTEM
A
B
C
D
A
CUR / VLT
GND
13
B
CUR / VLT
mA
VLT
-
+
15
14
CUR / VLT
GND
mA
VLT
GND
-
+
-
+
+
16
18
19
17
HYBRID CONTROL
o
F
OD=35
<<A>> B
100% 50%
STAGE MENU
D
mA
mA
VLT
+
+
+
24
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
OUTDOOR
TEMP
T
O
25
26
RUNPROGRAM
C
CUR / VLT
mA
VLT
GND
-
+
+
20
23
21
22
SYS=145
SYSTEM
PROVE
TEMP
/DHW
T
O
28
29
27
O
30
o
F
SHUTDOWN
/TSTAT
/SETBACK
O
31
EXTENSION
MODULE
RS-485
120VAC Power
Four N.O. Boiler startup relay
outputs. Each is wired in series
with each boiler's limit circuit.
When connecting the control Outdoor Air
Sensor and System Sensor, no polarity is
observed. Prove terminals must be connected
for control to operate boilers.
System Output controls
pumps, valves, or other
system components.
Four modulation/staging outputs can be
4-20mA or Voltage. Go to Startup Menu
to determine the type of output for each stage.
Connect Extension panels to add
additional stages using a RJ11 cable(cable
provided with Extension) and RJ45-RJ11
Adaptor (Supplied with control) only or add
X-BAC BACnet Interface Module using RJ45
(cable provided with X-BAC Module)
PART NUMBER # CA009200
HT# 059295-00 A
6
M4-LHS Installation and Operation Manual
EXTENSION LAYOUT
Extension Selection Switch to determine
Stage letters and LED colors.
Ext-A Stages E - J and all LEDs are Green
Ext-B Stages K - P and all LEDs are Red
This switch is covered with the Wiring Enclosure.
LED indicates the
associated relay status.
PWR
L N
1 2
C US
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
LISTED
99RA
K M OL N P
E
3 4F5 6G7 8H9 10I11 12
FULL MODULATION SEQUENCING EXTENSION
E
G
I
Comm
J
11 12
M4Ext
K
M
O
L
F
N
H
J
P
Power
CAUTION:
More than one disconnect switch may be required
to de-energize the equipment before servicing.
VLTmA
1514
CUR / VLT
GND
16
VLTmAGND
181716
Ext B
CUR / VLT
GND
19
VLTmAGND
212019
Ext A
K ML N
E F G H
CUR / VLT
GND
13
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
Risk of Electric Shock.
CUR / VLT
VLTmAGND
GND
242322
22
O P
I J
CUR / VLT
GND
25
VLTmA
2726
CUR / VLT
GND
28
EXTENSION
VLTmAGND
302916
MODULE
RS-485
120VAC Power
outputs. Each is wired in series
with each boiler's limit circuit.
4-20mA or Voltage. Go to the control Startup
Menu to determine the type of output for each stage.
M4-LHS Installation and Operation Manual
Six N.O. Boiler startup relay
Six modulation/staging outputs can be
PART NUMBER # CA004400
Connect to any M4-LHS
and additional Extension panels to add
additional stages using a RJ11 cable only
(cable provided with M4Ext).
HT# 059295-00 A
7
FEATURES
Laars designed the M4-LHS with Hydronic building heating, using both condensing and non-condensing boilers, as the primary purpose.
In addition, the M4-LHS is capable of controlling modulating and staging boilers. With this in mind, many of the M4-LHS features can
be utilized to ease, enhance, and improve your system performance.
Condensing and Non-Condensing Boilers Can be Modulating or Multi-Stage.
The M4-LHS can operate both modulating and staging boilers. Just specify each of the Condensing and Non-Condensing boiler group
type and the M4-LHS activates the groups based on an adjustable set of criteria.
PID Type Logic
The M4-LHS's control algorithms allow it to look at the rate of change in the system. If the system temperature is changing quickly,
the M4-LHS reacts quickly to adjust the modulating stages’ output. If the system temperature changes slowly, the M4-LHS shall make
slow and gradual output adjustments. Therefore, the M4-LHS adapts to specic system requirements and minimizes uctuations around
the set point.
Controls 0-10 V or 4-20 mA modulating Burners
Whenever any of the Condensing or Non-Condensing group type is set to Modulating, the M4-LHS accurately controls the output from
0 to 100% of modulation for each of these different types of motors. Moreover, a single M4-LHS can control multiple modulating burners
each with a different modulating signal.
Controls On/Off, 2-Stage, 3-Stage, or 4-Stage Burners
Whenever one of the Condensing or Non-Condensing group Type is set to Staging, the M4-LHS accurately sequences the stages using
a PID logic.
Digital Display of all System Settings
The M4-LHS'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 lead stage of each group promotes even wear. The M4-LHS has three modes of rotation: Manual, Last On, or Time. The
Time rotates the lead stage every selected period from every hour to every 60 days.
Outdoor Reset or Set Point
The M4-LHS has a hydronic outdoor temperature reset function. This allows the M4-LHS to change the set point based on outdoor
temperature. Furthermore, additional settings have been added to ne tune this operation, like Offset, Minimum, and Maximum Water
Temperature and night setback schedule.
System Output
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. It energizes 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.
Normal or Parallel Modulation
The M4-LHS can stage modulating boilers as needed. In Normal Modulation, it increases the lead boiler modulation until it reaches
its Modulation Start percent adjustment. Then, the M4-LHS starts the next boiler and so on. Moreover, the M4-LHS offers a parallel
mode that can modulate several boilers together as a single large boiler. This mode is useful when used with condensing boilers as they
run more efcient at lower modulation. Thus, it is better to run several boilers at lower modulation than to run a single boiler at full re.
Add up to 16 Boiler Stages (Optional)
As a stand-alone, the M4-LHS is designed to control four stages. However, it has the capability of expanding its control to two extension
panels each with six boiler stages. Thus, the M4-LHS can control a total of up to 16 boiler stages.
HT# 059295-00 A
8
M4-LHS Installation and Operation Manual
Setback or Day/Night Scheduling
Two Setback modes are available for the M4-LHS:
• 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 24.
• The Setback mode uses an external signal to switch the operation of the M4-LHS in and out of setback mode (only available when
Setback is selected as the Setback/Shutdown Startup option).
Remote Set point (EMS 4-20mA)
By connecting the control to the optional 4-20mA EMS Interface (X-SIG), the control shall be capable of accepting a remote set point.
BACnet MS/TP Communication
An optional BACnet Interface Module (X-BAC) (CA009100) can be used to connect the control to a BACnet MSTP network for remote
access.
MAKE SURE YOU HAVE THE RIGHT CONTROL
If you need the M4-LHS to do additional tasks that either are not listed or do not know how to congure them, contact your local
Laars representative.
Setting an Initial Program will ease the conguration of the M4-LHS and will give the opportunity to utilize many of the energy saving
features while giving 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 10
• Setting the System Startup. See "Startup Settings" on page 19.
• Setting the System Operating Settings. See "Operating Settings" on page 27
• Setting the Stages. See "Modulating Boiler Operating Settings" on page 33. Also, see "Staging Boiler Operating Settings" on page 34
• Adjusting Reset Ratio and Water Offset (In Reset Mode Only). See "Reset Ratio" on page 27
M4-LHS Installation and Operation Manual
HT# 059295-00 A
9
INSTALLATION
Each of the M4-LHS or Extension consists of three primary enclosure components.
• TheEnclosureDisplayModule: contains the control electronic board, display, buttons, LEDs, and electric wiring terminals.
It has two screws to hold it to the base. A program conguration switch, used to adjust the control settings, is placed above the
terminals. This switch is enclosed with the enclosure wiring cover for security. Wiring terminals are of the plug-in type to ease
installation and removal.
• TheEnclosureBase: contains the holes to mount and hold the control against the wall or any at surface. All other enclosure
components mount on the base. The bottom section of the Enclosure Base contains the wiring chamber with knockouts on the
bottom to ease installation.
• TheEnclosureWiringCover: seals the wires from the external environment. It has two screws to hold it the base and a hole to
secure a lock on the wiring enclosure. A plastic web that separates the wiring chamber into high and low volt sections has been
provided.
MOUNTING THE ENCLOSURE
• Select a location near the equipment to be controlled.
• The surface should be at and sufciently wide and strong to hold the M4-LHS or the Extension.
• Keep the control away from extreme heat, cold, or humidity. Ambient operating temperature is from 20 to 120°F.
• Remove the Enclosure Wiring Cover from the control enclosure by removing the two bottom screws.
• Remove the Enclosure Display Module by removing the enclosure middle screws.
• Screw the Enclosure Base to the surface through the upper and lower mounting holes on the back of the enclosure.
• Replace the Enclosure Display Module and replace the enclosure middle screws.
• Do not replace the enclosure wiring cover until all wiring is done.
• When purchasing a padlock for the enclosure, the maximum shank diameter should not exceed ¼"
Enclosure Display Module
Enclosure Wiring Cover Enclosure Base
Hole for optional lock
Mounting Holes
Display Mounting Screws
Wiring Cover
Mounting Screws
HT# 059295-00 A
10
M4-LHS Installation and Operation Manual
INSTALL THE SENSORS
System
Strap-On
Sensor
Shield
Not connected
Plastic
Tie-Wraps
Around Pipe
Strap-On Sensor
Outdoor Sensor
System Sensor Installation
• Only use the System sensor (CA002500 or equivalent) provided with the unit.
• The sensor wires can be extended up to 500' using a shielded 2-conductor cable
(Belden #8760 or equivalent). Do not ground the shield at the sensor but at the
panel using one of the terminals marked with an “O”.
• Do not run sensor wires in conduit with line voltage wiring.
• Install a 3/8"ID 1/2"NPT immersion well.
• If installing the system sensor on the supply, insert the sensor in a well with heat
paste approximately 5' feet past the boiler loop outlet on the common supply
header but before any major takeoffs. The sensor must be located where it sees
the output of all the boiler stages. If a boiler is piped so that the sensor does not
see its output, the M4-LHS will not sequence the boilers correctly.
• The sensor can also be installed on the return to the boilers after all major returns
and before any boiler. However, when setting the reset ratio and the offset, the
user must consider the temperature drop across the building loop.
WARNING
Use only the System and Outdoor Air sensors included with the control. Do
not use boiler sensors as it will cause operational problems.
Outdoor Sensor Installation
• Only use the Laars Outdoor Air Sensor group included with the unit (CA006500).
• Locate the sensor in the shade on the north side of the building. The sensor
should never be in direct sunlight.
• Be sure the location is away from doors, windows, exhaust fans, vents, or other
possible heat sources.
• The sensor should be mounted approximately 10' feet above ground level.
• Adhere the Outdoor Label provided to the back of the sensor base.
• Use the Enclosure Base bottom knockout for the conduit. Use the locknut to hold
the conduit and enclosure base together. Screw the cover to the base.
• If screws are used to afx the enclosure to the wall, make sure to seal around the
sensor and wall except from the bottom.
• The sensor wires can be extended up to 500' using shielded 2-conductor cable
(#18/2). Do not ground the shield at the sensor but at the control using the
terminal marked with an “O”.
• Do not run sensor wires in conduit with line voltage wiring.
Immersion Heating System Sensor
Immersion Well
3/8" ID 1/2" NPT
Shield
Heating System
Sensor
Common Supply Pipe
Sensor Probe
ALERT
If the HSS can not sense the correct water
temperature, the M4-LHS will not provide
comfortable heat levels.
Seal around
sensor and wall
Outdoor Sensor
snap-in location
Mounting
screws
location
Outdoor
drip-hole
Outdoor Label
on back of Sensor
Shield
not connected
ALERT
Determining the proper location of the Outdoor Sensor is very important. The M4-LHS will base
the heat on the outdoor temperature information it receives from this location. If the sensor is in the
sun, or covered with ice, its reading will be different from the actual Outdoor Temperature (OD).
M4-LHS Installation and Operation Manual
Conduit
HT# 059295-00 A
11
WIRING
SYSTEM
A
B
C
D
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
3
4
5
6
7
8
9
10
11
12
13
15
14
17
16
18
20
19
21
24
23
29
25
27
26
28
32
30
31
-
+
+
T
T
O
O
RS-485
mA
GND
VLT
SYS
A
B
C
D
CUR / VLT
A
-
+
+
mA
GND
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLTBCUR / VLTCCUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 30VA MAX
INPUT RATINGS:
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
/TSTAT
M4-LHS
HYBRID CONTROL
32
31
RS-485
O
EXTENSION
MODULE
SHUTDOWN
/SETBACK
/TSTAT
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
29
32
30
31
RS-485
O
O
EXTENSION
MODULE
PROVE
/DHW
SHUTDOWN
/SETBACK
/TSTAT
RS-485
EXTENSION
MODULE
• All wiring must enter the enclosure through the bottom knockouts.
• Class 1 voltage wiring must utilize a different knockout and conduit from any Class 2 voltage wiring.
Wiring the Power
(Terminals 1, 2)
• Bring the 120VAC 60Hz power wires through the bottom left knockout of the enclosure.
• Connect the hot line to terminal marked L.
• Connect the neutral line to the terminal marked N.
• Laars recommends installing a surge suppressor on the power source to the M4-LHS.
WARNING
Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.
Laars recommends installing a surge suppressor on the power source to the M4-LHS.
Wiring the Sensors
WARNING
Connect the shield at the control terminal end and cut the shield wire at the sensor end.
To avoid operational problems, use only the System and Outdoor Air sensors included with the control.
System Sensor Wiring
(Terminals 27, 28)
• A M4-LHS must be connected to a System Temperature sensor (CA002500 or equivalent) located in the common
header. The sensor must be inserted in a 3/8 ID well using heat paste.
• Temperature sensor wires can be extended up to 500’ by splicing its wires with a shielded 2-conductor cable
(Belden #8760 or equivalent (#18/2)).
• Temperature sensors have no polarity. Connect the two wires from the sensor to the M4-LHS terminals marked
SYSTEM TEMP 27, 28.
• Connect the sensor shield to the circled terminal 28 with one of the sensor wires.
Outdoor Sensor Wiring
(Terminals 25, 26)
• The M4-LHS will vary the system Set Point based on outdoor temperature. In addition, the Outdoor Air Sensor
group (CA006500) is used as an Outdoor Cutoff. The M4-LHS will disable all boilers when the outdoor
temperature is above the adjustable Outdoor Cutoff temperature.
• For an outdoor sensor use the outdoor sensor provided.
• The sensor wires can be extended up to 500’ using shielded 2-conductor cable (Belden #8760 or equivalent (#18/2)).
• Temperature sensors have no polarity. Connect the wires from the outdoor sensor to the M4-LHS terminals marked
• Connect the shield to the circled terminal 26 with one of the sensor wires.
OUTDOOR TEMP - 25, 26.
Wiring the Shutdown, Tstat, or Setback
(Terminals 31, 32)
• The Shutdown will be available when selected as the Shutdown/Tstat/Setback mode from the Startup menu. See
• The Shutdown feature can be used whenever it is desirable to turn off the M4-LHS stage outputs from a remote
• The Tstat option, when selected from the Shutdown/Tstat/Setback startup menu, offer the capability of controlling
• The thermostat will send the M4-LHS a call for heat by shorting terminals 31 and 32.
"Shutdown/Tstat/Setback Mode" on page 24. This will provide the user with an adjustable Day/Night Schedule. See
"Day - Night Schedule" on page 36.
location or another controller (i.e. EMS input).
the operation of the M4-LHS based on a thermostat input. This will provide the user with a adjustable Day/Night
Schedule.
PWR
N
L
1
2
Line
Neutral
120VAC
Power Source
SYSTEM
TEMP
T
O
28
27
System Sensor
OUTDOOR
TEMP
T
O
25
26
Outdoor Sensor
SHUTDOWN
/TSTAT
/SETBACK
O
O
32
30
31
Shutdown,
T-Stat, or
Setback Signal
PROVE
/DHW
O
30
29
Sensor Shield
SYSTEM
TEMP
T
O
28
27
Sensor Shield
HT# 059295-00 A
12
M4-LHS Installation and Operation Manual
• When the Shutdown input is enabled by closing the dry contact, or when the Tstat input is disabled by opening the
RS-485
EXTENSION
MODULE
RS-485
EXTENSION
MODULE
SYSTEM
A
B
C
D
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
7
8
9
10
11
12
13
15
14
17
16
18
20
19
21
24
23
29
25
27
26
28
32
30
31
-
+
+
T
T
O
O
RS-485
mA
GND
VLT
B
C
D
CUR / VLT
A
-
+
+
mA
GND
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLTBCUR / VLTCCUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 30VA MAX
INPUT RATINGS:
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
/TSTAT
M4-LHS
HYBRID CONTROL
dry-contact, all active modulating boilers will immediately modulate down to low for the Soft-Off period, then turn
off. All staging boilers will turn off immediately.
• The System Output relay will remain active until the System Run-On Delay expires and then it will turn off.
• When Setback is selected in the Startup, a BMS/EMS or external clock can provide a Setback signal using these
input terminals. See "Shutdown/Tstat/Setback Mode" on page 24. No Day/Night Schedule will be available when
Setback is selected from the Shutdown/Tstat/Setback mode in the Startup menu.
• Bring the two wires from the dry contact to the terminals marked SHUTDOWN/TSTAT/SETBACK- 31,32.
• The signal must be a dry contact only. No voltage can be placed across the SHUTDOWN/TSTAT/SETBACK
terminals.
Wiring the Prove
(Terminals 29, 30)
• The Prove feature checks system component operation and must be selected in the Startup Menu from the Prove/
DHW Sharing menu. See "Prove/Indirect Domestic Hot Water (DHW) Priority" on page 24.
• A typical use of this feature is to check for pump ow or combustion air damper status before ring any boiler.
• If the PROVE input is open on a call for heat, the M4-LHS enables only the System Output. All boiler outputs
will be off when the PROVE input is open.
• A factory-installed jumper provides the System Prove signal. Do not remove the jumper unless it is replaced with
a System Prove signal or these terminals are to be used for DHW call input.
• Bring the two wires from the dry contact to the terminals marked PROVE - 29, 30.
• Prove Input terminals can accept a dry-contact signal only. No voltage can be placed across these terminals.
SHUTDOWN
PROVE
/DHW
O
O
30
29
Prove Signal
/TSTAT
/SETBACK
O
32
31
WARNING
The PROVE input cannot be used as a safety limit. All equipment must have its own
certified limit and safety controls as required by local codes. If Prove is selected in the
startup menu, no boiler stage will start unless Prove terminals are shorted. DO NOT remove
the PROVE jumper supplied unless replacing it with a Prove signal.
Wiring the Indirect Domestic Hot Water (DHW) Call
(Terminals 29, 30)
• DHW can be used to raise system Set Point to the DHW Set Point as well as manage the System Pump according
to the DHW Priority setting. One of the DHW options must be selected from the Prove/DHW Sharing Startup
menu. See "Prove/Indirect Domestic Hot Water (DHW) Priority" on page 24.
• Remove the existing jumper and wire an aquastat or a control to provide dry-contact closure to the DHW Call - 29,
30 terminals.
• DHW Call terminals can accept dry contact signals only. No voltage can be placed across these terminals.
Wiring the System Output
(Terminals 3, 4)
• The SYS output relay will energize and remain constantly energized whenever the outdoor temperature is below
the Outdoor Cutoff.
• When the outdoor temperature rises 2°F above the Outdoor Cutoff, the SYS output will remain energized for the
period set by the System Run-On then de-energize. See "System Run-On" on page 31.
• In addition, the System output will energize during summer DHW calls when DHW No Priority is selected. See
"Prove/Indirect Domestic Hot Water (DHW) Priority" on page 24.
• The SYS output has one Normally Open (N.O.) relay contact rated for (1/8 HP).
• The N.O. contacts are dry contacts only. They do not source any voltage.
• Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.
PROVE
/DHW
O
O
30
29
28
Indirect
DHW Signal
SYS
3
4
L
N
System Pump
or Pump Starter
SHUTDOWN
/TSTAT
/SETBACK
O
32
31
A
5
6
M4-LHS Installation and Operation Manual
HT# 059295-00 A
13
Wiring the Boilers
SYSTEM
A
B
C
D
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
9
10
11
12
13
15
14
17
16
18
20
19
21
24
23
29
25
27
26
28
32
30
31
-
+
+
T
T
O
O
RS-485
mA
GND
VLT
C
D
CUR / VLT
A
-
+
+
mA
GND
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLTBCUR / VLTCCUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 30VA MAX
INPUT RATINGS:
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
/TSTAT
M4-LHS
HYBRID CONTROL
SYSTEM
A
B
C
D
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
13
15
14
17
16
18
20
19
21
24
23
29
25
27
26
28
32
30
31
-
+
+
T
T
O
O
RS-485
mA
GND
VLT
CUR / VLT
A
-
+
+
mA
GND
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLTBCUR / VLTCCUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
/TSTAT
M4-LHS
HYBRID CONTROL
SYSTEM
A
B
C
D
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
17
18
20
19
21
24
23
29
25
27
26
28
32
30
31
T
T
O
O
RS-485
+
+
mA
VLT
-
+
+
mA
GND
VLT
+
+
mA
22
-
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLTBCUR / VLTCCUR / VLT
D
PROVE
/DHW
SHUTDOWN
/SETBACK
/TSTAT
M4-LHS
HYBRID CONTROL
RUNPROGRAM
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
29
25
27
26
28
32
30
31
T
T
O
O
RS-485
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
PROVE
/DHW
SHUTDOWN
/SETBACK
/TSTAT
HYBRID CONTROL
• When wiring Condensing and Non-Condensing boilers make sure that the Condensing boilers use the rst
stages and the Non-Condensing boilers use the following stages. That is, if the installation had two Condensing
Modulating boilers and two Non-Condensing Staging On/Off boilers, Stage A and B must be used by the
Condensing boilers while Stage C and D must be used by the Non-Condensing boilers.
Wiring Boiler Activation or On/Off Staging Boilers
(A Terminals 5, 6), (B Terminals 7, 8), ...
• Each boiler output has a Normally Open (N.O.) dry-contact relay. They do not source any power.
• Wire the N.O. relay contacts in series with the unit’s limit circuit.
• Note that some modulating boilers may not require the use of these outputs.
A
SYS
5
3
4
Boiler
Boiler Enable
Output
B
678
Wiring Multi-Stage Boilers
(For Staging Boiler Types Only) See Page 19
• Each stage on a multi-stage boiler must use one of the N.O. relays.
• Note that on the display of the M4-LHS each multi-stage boiler will
OD=55oF SYS=142
<<AB>> CD
HI LOW
consist of a multiple letters.
• Each stage output has one Normally Open (N.O.) relay contact that
does not source any power.
STAGE ◄ ► MENU
Multi-Stage Boiler
WARNING
Class 1 voltages must enter the enclosure through a different opening from any Class 2 voltage wiring.
Wiring to Modulating Boilers
The M4-LHS can modulate any combination of current or voltage boiler signals. See "Modulating Output Type" on
page 23. Some modulating boilers may require the use of the stage output relays in addition to the modulating output.
WARNING
The Modulating Output Type must be set to match the boiler modulating
signal prior to wiring the boiler signal to avoid control or equipment damage.
Wiring the 4-20mA Modulating Boilers
(A Terminals 13, 14), (B Terminals 16, 17),...
• The M4-LHS can operate up to four 4-20 mA modulating motors.
• The Extension can operate up to six 4-20 mA modulating motors.
• The M4-LHS and the Extension sources excitation voltage for the
4-20mA signal.
• Wire the (-) from the boiler modulating motor to the (GND) terminal
on the M4-LHS. That is for boiler A, the modulating (GND) terminal
will be 13.
• Wire the (+) from the boiler modulating motor to the (mA+) terminal
on the M4-LHS. That is for boiler A, the modulating (mA+) terminal
will be 14.
OD=55oF SYS=142
<A> B
80% 50%
STAGE ◄ ► MENU
Modulating Boiler (Modulating
Boiler Type)
D
o
F
C
8
9
10
11
12
Low
High
2-Stage Boiler
o
F
A
CUR / VLT
mA
VLT
GND
-
+
+
15
13
14
4-20mA
-
Boiler 4-20mA
Modulation Output
Burner
Motor
+
GND
-
16
Wiring Voltage Modulating Boilers
(A Terminals 13, 15), (B Terminals 16, 18),...
• The M4-LHS can operate up to four 0-10V modulating motors.
• The Extension can operate up to six 0-10V modulating motors.
• Wire the (GND) from the boiler modulating motor to the (GND) terminal on the M4-LHS. For boiler D, the
modulating (GND) terminal is be 22.
• Wire the (VLT+) from the boiler modulating motor to the (VLT+)terminal on the M4-LHS. For boiler D, the
modulating (VLT+) terminal is be 23.
HT# 059295-00 A
14
M4-LHS Installation and Operation Manual
C
D
CUR / VLT
mA
mA
mA
VLT
VLT
GND
-
+
+
+
+
+
20
GND
23
21
24
22
Voltage
Burner
Motor
Boiler Voltage
Modulation Output
V+
Connecting to the Extensions and 4-20mA EMS Interface
SYSTEM
A
B
C
D
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
HYBRID CONTROL
RUNPROGRAM
ALERT
To set the Extension to a specific letter, remove the wiring cover and switch the Ext A/Ext B to the
desired letter. DO NOT set both extensions to the same letter to avoid errors.
• The M4-LHS is equipped with a RJ45 socket and a RJ45 to RJ11 Adaptor to connect to extension panels and X-SIG 4-20mA EMS
Interfaces. The Extension is equipped with two RJ11 sockets. It comes packaged with a RJ11 cable to connect to M4-LHS and an
additional Extension. Use the RJ45 to RJ11 Adaptor on the M4-LHS.
• The order in which the control, the extensions, and the interface are wired is not observed.
• Set each Extension to a different letter (EXT-A or EXT-B). The M4-LHS assigns the stage letters based on the extension letter
selected.
• Extension-A operates stages (E - J) and all the LEDs are Green. However, Extension-B operates stages (K - P) and all the LEDs
are Red. .
• Congure the Modulating and Sequencing Output Types after connecting the Extension panels to be able to congure their outputs.
See "Boiler Type" on page 19
• Use the 6-wire RJ11 cable supplied with the extension for proper operation.
M4-LHS
M4-LHS
SYSTEM
OUTPUT RATINGS:
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
FOR ALL CIRCUITS
INPUT RATINGS:
INPUT RATINGS:
115VAC 60Hz , 30VA MAX
115VAC 60Hz , 30VA MAX
USE COPPER WIRE,
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
CLASS 1 WIRE ONLY.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
CAUTION: RISK OF ELECTRIC SHOCK
CAUTION: RISK OF ELECTRIC SHOCK
LISTED
More than one disconnect switch may be required
More than one disconnect switch may be required
99RA
to de-energize the equipment before servicing.
to de-energize the equipment before servicing.
D
C
B
A
SYS
PWR
SYS
PWR
L
N
L
N
3
1
2
3
1
2
D
C
B
A
5
8
6
7
9
10
4
11
12
5
6
7
9
8
10
4
11
12
SYSTEM
A
A
B
B
C
C
D
D
B
A
A
B
CUR / VLT
CUR / VLT
CUR / VLT
CUR / VLT
CUR / VLT
CUR / VLT
mA
VLT
mA
VLT
GND
GND
GND
mA
mA
VLT
GND
GND
GND
VLT
-
-
-
-
-
-
+
+
+
+
+
+
+
+
19
15
13
18
16
14
17
19
15
13
18
16
14
17
4-20 mA EMS
4-20mA INPUT
SignalGND
+
2
1
3
EMS/BMS
Temperature
Set PointInput
EMS/BMS Sources
Excitation Voltage
CONDENSING AND NON-CONDENSING
Full Modulation Sequencing Control
o
F
SYS=145oF
OD=35
<<A>> B
100% 50%
STAGE MENU
DO NOT APPLY ANY VOLTAGE
DO NOT APPLY ANY VOLTAGE
RUNPROGRAM
RUNPROGRAM
20
20
C
D
D
C
CUR / VLT
CUR / VLT
mA
mA
VLT
mA
VLT
GND
VLT
mA
mA
mA
GND
VLT
-
-
+
+
+
+
+
+
+
+
+
+
23
22
24
21
23
21
22
24
RJ45 to RJ11
Adaptor
TO INPUT TERMINALS
TO INPUT TERMINALS
SYSTEM
OUTDOOR
SYSTEM
OUTDOOR
TEMP
TEMP
TEMP
TEMP
T
T
O
T
T
O
26
25
27
26
25
27
X SIG
RS485
EXTENSION
CONNECTORS
(-)
(+)
O
O
28
28
PROVE
PROVE
/DHW
/DHW
O
O
30
29
30
29
RJ11
SHUTDOWN
SHUTDOWN
/SETBACK
/SETBACK
31
31
M4-Extension A
M4-Ext
FULL MODULATION SEQUENCING EXTENSION
K
F
E
M
H
G
O
J
I
Power
Comm
EXTENSION
EXTENSION
/TSTAT
MODULE
MODULE
RS-485
O
RS-485
O
32
32
PWR
L N
1 2
K M OL N P
E
3 4F5 6G7 8H9 10I11 12
J
13114
Ext A
K ML N
E F G H
CUR / VLT
VLTmA
GND
1716
15
L
N
P
CAUTION:
More than one disconnect switch may be required
to de-energize the equipment before servicing.
Ext B
CUR / VLT
CUR / VLT
GND
VLTmAGND
VLTmAGND
GND
21
201916
232219
18
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
Risk of Electric Shock.
O P
I J
CUR / VLT
CUR / VLT
VLTmAGND
VLTmA
GND
GND
262522
2928
27
24
CUR / VLT
GND
30
EXTENSION
MODULE
VLTmAGND
RS-485
323116
RJ11
Each Extension Panel or 4-20mA EMS
Interface comes with Connection Cable.
M4-Extension B
M4-Ext
PWR
L N
1 2
K M OL N P
E
3 4F5 6G7 8H9 10I11 12
FULL MODULATION SEQUENCING EXTENSION
K
F
E
M
H
G
O
J
I
Power
Comm
Ext A
K ML N
E F G H
J
CUR / VLT
VLTmA
GND
1716
15
13 14
L
N
P
CAUTION:
More than one disconnect switch may be required
to de-energize the equipment before servicing.
Ext B
CUR / VLT
CUR / VLT
GND
VLTmAGND
VLTmAGND
GND
21
201916
232219
18
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
Risk of Electric Shock.
O P
I J
CUR / VLT
CUR / VLT
VLTmAGND
VLTmA
GND
GND
262522
2928
27
24
CUR / VLT
GND
30
EXTENSION
MODULE
VLTmAGND
RS-485
323116
RJ11
M4-LHS Installation and Operation Manual
HT# 059295-00 A
15
Connecting to BACnet Interface Module
• The M4-LHS can communicate to BACnet MSTP networks when used the X-BAC BACnet Interface Module (CA009100). The
module must be purchased separately.
• The BACnet Interface Module comes with an RJ45 cable.
• Both the M4-LHS and the BACnet Interface Module are equipped with a RJ45 socket (RS485) to connect to communicate to each
other.
• The Interface BACnet Module must be wired to the BACnet MSTP network using the RS485 terminals A, GND, and B.
• If both an extension panel and the BACnet Interface Module are to be used, connect the RJ11 socket on the BACnet Interface
Module to the extension.
• Set the BACnet parameters. See "BACnet MSTP Communication Menu" on page 26.
X-BAC
BACnet Interface Module
PWR
L
N
1
2
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz , 30VA MAX
USE COPPER WIRE,
CLASS 1 WIRE ONLY.
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
CAUTION
: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
SYS
A
B
C
5
3
6
4
7
8
9
10
11
D
12
M4-LHS
A
B
C
D
RUNPROGRAM
A
B
CUR / VLT
GND
-
13
14
C
CUR / VLT
CUR / VLT
mA
VLT
GND
mA
VLT
GND
mA
-
-
+
+
+
+
+
15
16
18
19
17
20
HYBRID CONTROL
D
CUR / VLT
VLT
GND
mA
mA
VLT
-
+
+
+
+
23
21
22
24
DO NOT APPLY ANY VOLTAGE
TO INPUT TERMINALS
OUTDOOR
SYSTEM
PROVE
TEMP
TEMP
/DHW
T
O
T
O
O
25
26
28
29
27
30
SHUTDOWN
/TSTAT
/SETBACK
31
MSTP
A GND B
1 2 3
B (-)
A (+)
EXTENSION
MODULE
RS-485
O
32
Ground
To BACnet
MSTP
PRODUCT
COMM
RJ45 Cable
RS485
RJ45 RJ11
RJ45
RJ45 Communication Cable
Extension
M4Ext
PWR
L N
1 2
K M OL N P
E
3 4F5 6G7 8H9 10I11 12
FULL MODULATION SEQUENCING EXTENSION
K
E
M
G
O
I
Comm
J
13 14
L
F
N
H
J
P
Power
Ext A
K ML N
E F G H
CUR / VLT
CUR / VLT
VLTmA
GND
GND
1716
15
18
OUTPUT RATINGS:
120VAC, 6A RESISTIVE
1A PILOT DUTY, 15A TOTAL
FOR ALL CIRCUITS
INPUT RATINGS:
115VAC 60Hz, 12VA MAX
Use Copper Conductors Only.
CAUTION:
Risk of Electric Shock.
More than one disconnect switch may be required
to de-energize the equipment before servicing.
Ext B
CUR / VLT
GND
VLTmAGND
21
201916
I J
CUR / VLT
CUR / VLT
VLTmAGND
VLTmAGND
GND
GND
232219
262522
27
24
O P
CUR / VLT
VLTmA
GND
2928
30
VLTmAGND
323116
RJ11
ACTIVATE THE BATTERY
• The battery enables to control to maintain the clock time.
• Unscrew and remove the Enclosure Display Module to reveal the back of the control
CPU Board.
• Remove the plastic strap that covers the battery. The battery holder contacts should be
touching the battery. The control has a coin Lithium battery (CR2032) that is used to
maintain the control's time during power outages. This battery can maintain the clock for
up to a total of 100 days.
EXTENSION
MODULE
RS-485
RJ11 Extension Cable
Battery
ALERT
Do not install the battery unless you plan to keep the control continuously powered. If the
control has no power, the battery will lose its charge in 100 days.
HT# 059295-00 A
16
M4-LHS Installation and Operation Manual
HYBRID STARTUP MENU
-------- SETTINGS ----
Season Winter
System Target 140
<System Settings>
<Maintenance>
<System Startup>
BACK ▲ ▼ SELECT
-EMS 20ma SETPOINT-
220
F
o
[ ]
BACK ▲ ▼ SAVE
--- SWITCH DELAY ---
0.5Hour
[ ]
BACK ▲ ▼ SAVE
Page 21
HEAVY LOAD
-SEQUENCE #2 GROUP-
No
Yes
BACK ▲ ▼ SAVE
Page 22
CONDENSING
- MODULATING MODE -
Normal
Parallel
BACK ▲ ▼ SAVE
Page 21
NON-CONDENSING
---- BOILER TYPE ----
Modulating
Staging
BACK ▲ ▼ SAVE
NON-CONDENSING
-- BOILER NUMBER --
1
[
]
BACK ▲ ▼ SAVE
Page 24
- SETBCK/SHUTDOWN -
Shutdown/Disable
Tstat/Enable
Setback
BACK ▲ ▼ SAVE
Shutdown
Page 25
--- BOOST MODE ---
30 Minutes
Disable
BACK ▲ ▼ SAVE
M4-LHS Installation and Operation Manual
or Tstat
o
F
Page 20Page 21
Page 21
Page 24
Page 25
Setback
-- ARE YOU SURE? --
No
Yes
BACK ▲ ▼ SAVE
-EMS 4ma SETPOINT -
o
70
F
[ ]
BACK ▲ ▼ SAVE
--- SWITCH DIFF ---
o
10
F
[ ]
BACK ▲ ▼ SAVE
CONDENSING
---- BOILER TYPE ----
Modulating
Staging
BACK ▲ ▼ SAVE
CONDENSING
-- OUTPUT B TYPE --
4-20mA
0-10volt
0-5volt
2-10volt
1-5volt
BACK ▲ ▼ SAVE
NON-CONDENSING
-- OUTPUT C TYPE --
4-20mA
0-10volt
0-5volt
2-10volt
1-5volt
BACK ▲ ▼ SAVE
- DHW SETPOINT -
180
F
o
[ ]
BACK ▲ ▼ SAVE
--- SENSOR FAULT ---
All Off
All On
BACK ▲ ▼ SAVE
Page 19
--- BOILER TYPE ---
Modulation
Hybrid
Yes
BACK ▲ ▼ SAVE
Page 19Page 20
--- SENSOR TYPE ---
Reset oF
Reset
o
C
4-20mA EMS
4-20mA EMS
BACK ▲ ▼ SAVE
Reset
Page 20
- SWITCH SETPOINT -
o
150
[ ]
BACK ▲ ▼ SAVE
Page 21
CONDENSING
-- BOILER NUMBER --
2
[ ]
BACK ▲ ▼ SAVE
Page 23
-- OUTPUT A TYPE --
4-20mA
0-10volt
0-5volt
2-10volt
1-5volt
BACK ▲ ▼ SAVE
Page 22
- MODULATING MODE -
Normal
Parallel
BACK ▲ ▼ SAVE
Page 24
PROVE/DHW SHARING
Prove
DHW Priority
DHW No Priority
No Priority (Summer)
BACK ▲ ▼ SAVE
All DHW Options
Page 26
--- BACNET MODE ---
Disable
Enable
BACK ▲ ▼ SAVE
Modulating
CONDENSING
NON-CONDENSING
F
HT# 059295-00 A
17
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