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Application 302P-3
Mechanical
Electrical
Two Switching Relay’s operate six heating zone circulators. The two controls are connected together using an expansion
bus wire. The master 302P fires the boiler when any zone calls for heat. If priority is selected, zones 2 through 6 shut
off when zone 1 is calling for heat.
DIP Switches
Master
T-stat 1 Priority On
Exercising On
DIP Switches
Member
T-stat 1 Priority Off
Exercising On
The 302P includes
internal circuitry
to support power
stealing thermostats.
External resistors are
not required.
Legend
A1 = DHW Tank Aquastat
B1 = Modulating Condensing Boiler
BP = Boiler Pump
P1 = Zone 1 DHW Tank Pump
A1
Expansion
B1
P1
P2
P3
P4
P5
P6
BP
302P
304P
Away
C R Rh W
70
Away
C R Rh W
Away
C R Rh W
R W
R W
FUSE 2
FUSE 7
FUSE 8
FUSE 3
FUSE 4
FUSE 5
FUSE 6
70 80
90
60
50
100
MOD MAX %
MASTER
MEMBER
OFF
OFF
OFF
4-20 mA
T-STAT 1 PRIORITY : 0N
EXERCISING : ON
POST PURGE : ON
MOD BOILER : 0-10V
RESERVED
FUSE 1
120 VAC
POWER
MOD
X X
tN4
POWER
ROOM
RESPONSE
T1
T2
T3
T4
T5
T6
A
DHW
C R W
BOILER
T-STAT 1
T-STAT 2
T-STAT 3
PRIORITY
PUMP 1
PUMP 2
PUMP 3
PUMP 4
PUMP 5
PUMP 6
L
-
+
N
L
N
L
N
L
N
L
N
L
N
L
N
tN4
A C R W
tN4
A C R W
T-STAT 4
tN4
A C R W
T-STAT 5
tN4
A C R W
T-STAT 6
EXPANSION
tN4
A C R W
tN4
A B C D E
FUSE 2
FUSE 7
FUSE 8
FUSE 3
FUSE 4
FUSE 5
FUSE 6
70 80
90
60
50
100
MOD MAX %
MASTER
MEMBER
OFF
OFF
OFF
4-20 mA
T-STAT 1 PRIORITY : 0N
EXERCISING : ON
POST PURGE : ON
MOD BOILER : 0-10V
RESERVED
FUSE 1
120 VAC
POWER
MOD
X X
tN4
POWER
ROOM
RESPONSE
T1
T2
T3
T4
T5
T6
A
DHW
C R W
BOILER
T-STAT 1
T-STAT 2
T-STAT 3
PRIORITY
PUMP 1
PUMP 2
PUMP 3
PUMP 4
PUMP 5
PUMP 6
L
-
+
N
L
N
L
N
L
N
L
N
L
N
L
N
tN4
A C R W
tN4
A C R W
T-STAT 4
tN4
A C R W
T-STAT 5
tN4
A C R W
T-STAT 6
EXPANSION
tN4
A C R W
tN4
A B C D E
+
T
T
-
B1
P1
P5
L
L
N
N
P2
P6
P3 P4
A1
T1
T4 T5
T2
T3
Post Purge On
Mod Boiler - depends on
boiler
Post Purge On
Mod Boiler - not applicable
P2 to P6 = Zone 2 through 6 Pump
T1 = WiFi Thermostat 561, 562 or 563
T2, T3 = Thermostat 518 or 519
T4 = Generic Power-Stealing Thermostat
T5 = Generic Bi-Metallic Strip Thermostat
