Dunkirk EXCELSIOR EXB4075 Installation, Operation & Maintenance Manual page 20

Figure 18 - Piping and Wiring Single Zone System With Domestic Hot Water DHW Priority
FIGURE 18
HYDROSTAT
MODEL 3250
TO OIL
BURNER
L
120 VAC
N
10 - HYDRONIC PIPING
DHW Heater
INDIRECT WATER
HEATER, AQUASTAT
OR THERMOSTAT
ARM-2P
CONTROL
WITH
PRIORITY
20
TANK
CONTROL
PRIORITY
ZONE
DATA PORT
+
T
1
ELECTRONIC
W
FUSE
+ +
+
CT
PRIORITY ON
X-X
1
X1 X1 X2 X2
L N
PRIORITY
ISOLATED ISOLATED
SWITCH SWITCH
120VAC CIRCULATORS
DHW
CIRC
T-STAT
THERMOSTAT
ZONE 2
COMMON
T T 2 T
R W R
24 VAC @ 1 VA
ZONE 1 ZONE 2
TO EXTRA
ZONE MODULE
PRIORITY ON
L N
2
L N
ZONE 2
120 VAC
CIRC