61
2.4.3.3 Wiring Diagram - Zone Pump System
NCB-H boilers can operate a heating system with up to 3 zones.
The following is the wiring diagram for a zone pump system with
3 zones.
Zone Pump Dry Contact Connections (no 24VAC power) and
Thermostats without 24VAC power
N
A/H
DHW PRI
L N L
N L
N L N L
Z3Z2Z1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir
COM NO NC
ZONE_V/V3
COM NO NC
ZONE_V/V2
COM NO NC
ZONE_V/V1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
Thermostat 3
Thermostat 2
Thermostat 1
N
A/H
DHW PRI
L N L
N L
N L N L
Z3Z2Z1
Zone pump 1
(max. 2.5 A)
Zone pump 2
(max. 2.5 A)
Zone pump 3
(max. 2.5 A)
Pump Ground
Neutral Neutral
(N)(N)
Line Line
(L)(L)
Neutral Neutral
(N)(N)
Line Line
(L)(L)
Neutral Neutral
(N)(N)
Line Line
(L)(L)
N
A/H
DHW PRI
L N L
N L
N L N L
Z3Z2Z1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
AC24VN
AC24VL
lLWCO
R
W
C
T/S_Recir
COM NO NC
ZONE_V/V3
COM NO NC
ZONE_V/V2
COM NO NC
ZONE_V/V1
SUPPLY
TEMPERATURE SENSOR
RETURN OUTDOOR T/S_ZONE3
R
W
C
T/S_ZONE2
R
W
C
T/S_ZONE1
R
W
C
Thermostat 3
Thermostat 2
Thermostat 1
N
A/H
DHW PRI
L N L
N L
N L N L
Z3Z2Z1
Zone pump 1
(max. 2.5 A)
Zone pump 2
(max. 2.5 A)
Zone pump 3
(max. 2.5 A)
Pump Ground
Note
●
If you have a 24 V thermostat,
connect it to the R & C
terminals on the boiler’s PCB.
●
The C terminals are for
optional connections with
24 V thermostats that have a
COMMON wire.