Hybrid startup settings, Ems 4ma and 20ma set points, Switch set point – LAARS M4-LHS - Installation Manual User Manual
Page 20: Switch differential
HT#
059295-00
A
20
M4-LHS Installation and Operation Manual
EMS 4mA and 20mA Set Points
4mA: can be set from 50°F/ 10°C to 200°F/93°C
Default: 70°F/ 21°C
20mA: can be set from 70°F/ 21°C to 220°F/104°C
Default:
220°F/ 104°C
Button: MENU/
• With the use of the 4-20mA EMS Interface, the M4-LHS will be able to receive a 4-20mA
signal as a set point from a BMS or an EMS system as the target set point.
• The 4mA and 20mA Set Point menus will follow the selection of the 4-20mA EMS sensor
type option or EMS input Mode.
• There must be at least a 20°F differential between the 4mA and 20mA temperature settings.
• Connect the 4-20mA EMS Control Interface to the M4-LHS RS485 connection.
• Any signal below 2.4mA or above 21.6mA will start an EMS shutdown. The display will
indicate that by displaying the message "Shutdown by EMS
".
-EMS 4ma SETPOINT -
70
o
F
[ ]
BACK
▲
▼ SAVE
-EMS 20ma SETPOINT-
220
o
F
[
]
BACK
▲
▼ SAVE
HYBRID STARTUP SETTINGS
See "Hybrid Logic Overview" on page 3.
Above the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
Target Switch
Set Point
= 120°F
Below the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
120°F
140°F
100°F
SWITCH MODE = Target Temperature
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
15
14
17
16
18
22
20
19
21
24
23
29
25
27
26
28
32
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
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=
25 oF
SYS=
145 oF
<>
B
100%
52%
System
Temp
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
15
14
17
16
18
22
20
19
21
24
23
29
25
27
26
28
32
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
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=
25 oF
SYS=
145 oF
<>
B
100%
52%
Above the Switch Set Point
Condensing are the Lead Group
Non-Condensing are the Lag Group
Outdoor Switch
Set Point
= 30°F
Below the Switch Set Point
Non-Condensing are the Lead Group
Condensing are the Lag Group
30°F
50°F
10°F
SWITCH MODE = Outdoor Temperature
COND
COND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
COND
COND
Outdoor
Temp
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
15
14
17
16
18
22
20
19
21
24
23
29
25
27
26
28
32
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
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=
25 oF
SYS=
145 oF
<>
B
100%
52%
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
15
14
17
16
18
22
20
19
21
24
23
29
25
27
26
28
32
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
GND
VLT
+
mA
TEMP
OUTDOOR
O
O
TEMP
SYSTEM
EXTENSION
MODULE
CUR / VLT
B
CUR / VLT
C
CUR / VLT
D
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
OD=
25 oF
SYS=
145 oF
<>
B
100%
52%
Switch Set Point
From 0ºF/ -18ºC to 200ºF/ 94ºC
Default: 150ºF/ 66ºC
Button: MENU/
• It is the set point at which the M4-LHS will switch between the Condensing Boiler Group
and Non-Condensing Boiler Group.
• The Condensing Boiler group will be the lead group when the Target Temperature is below
the Target Switch Set Point. However, the Non-Condensing Group will be the lead group
when the Target Temperature is above the Target Switch Set Point.
- SWITCH SETPOINT -
150
o
F
[
]
BACK
▲
▼ SAVE
Switch Differential
Adjustable from 5Fº / 3Cº to 20Fº / 11Cº
Default: 10Fº / 6Cº
Button: MENU/
• The Switch Differential controls the group switching. It allows the Calculated Target to
group over.
• The default value is a good start to avoid oscillation between Condensing and Non-
Condensing Boiler groups, particularly if no Switch Delay was set. See next setting.
--- SWITCH DIFF ---
10
o
F
[
]
BACK
▲
▼ SAVE
COND
COND
NON-
COND
NON-
COND
NON-
COND
NON-
COND
COND
COND