Wiring the prove, Wiring the domestic hot water (dhw) call, Wiring the system output – LAARS M4-Ext - Installation Manual User Manual
Page 12: Warning, Laars heating systems, Mini-mod-cnc, A b c d
12
• When the Shutdown input is enabled by closing the dry contact, or when the Tstat input is disabled by opening the 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 19. No Day/Night Schedule will be available when Setback is selected from the
Shutdown/Tstat/Setback mode in the Startup menu.
• The signal must be a dry contact only. No voltage can be placed across the SHUTDOWN/TSTAT/SETBACK terminals.
• Bring the two wires from the dry contact to the terminals marked SHUTDOWN/TSTAT/SETBACK- 31,32.
WiRiNg THE PROvE
(TERMinALS 29, 30)
• The Prove feature is provided to check system component operation and must be selected in the Startup Menu
from the Prove/DHW Sharing menu. See "Prove/Domestic Hot Water (DHW) Priority" on page 19.
• A typical use of this feature is to check for pump flow or combustion air damper status before firing any boiler.
• If the PROVE input is open on a call for heat, the M4-CNC will enable 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 will be replaced
by 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. No voltage can be placed
across the PROVE terminals
• Prove Input terminals can accept a dry-contact signal only. No voltage can be placed across these terminals.
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.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
1 2
RUN
PROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
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
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=
25
o
F
SYS=
145
o
F
<>
B
100%
52%
Mini-MOD-CNC
Prove Signal
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
1 2
RUN
PROGRAM
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
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
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=
25
o
F
SYS=
145
o
F
<>
B
100%
52%
Mini-MOD-CNC
DHW Signal
WiRiNg THE 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/Domestic Hot Water (DHW) Priority" on page 19.
• Wire an aquastat or a control to provide dry-contact closure on the DHW Call terminals.
• Remove the jumper on the DHW terminals for proper operation.
• 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 whenever the outdoor temperature is below the Outdoor Cutoff.
• The SYS relay will remain constantly energized while 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. See "System Run-On" on page 24.
• In addition, the System output will energize during summer DHW calls when DHW No Priority is selected. See
"Prove/Domestic Hot Water (DHW) Priority" on page 19.
• The SYS output has one Normally Open (N.O.) relay contact rated for (1/8HP).
• 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.
SYSTEM
A
B
C
D
Condensing / Non-Condensing Control
1 2
RUN
PROGRAM
FOR ALL CIRCUITS
120VAC, 6A RESISTIVE
OUTPUT RATINGS:
1A PILOT DUTY, 15A TOTAL
115VAC 60Hz , 12VA MAX
INPUT RATINGS:
USE COPPER CONDUCTORS ONLY
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
CAUTION: RISK OF ELECTRIC SHOCK
More than one disconnect switch may be required
to de-energize the equipment before servicing.
PROVE
/DHW
SHUTDOWN
/TSTAT
/SETBACK
ENCLOSED
ENERGY
MANAGEMENT
EQUIPMENT
99RA
OD=
25
o
F
SYS=
145
o
F
<>
B
100%
52%
Mini-MOD-CNC
System Pump
or Pump Starter
L
N
LAARS Heating Systems
HT# 059104-00 B