Dunkirk EXCELSIOR EXB4075 Installation, Operation & Maintenance Manual page 27

FIGURE 23
HYDROSTAT
MODEL 3250
BLR
CIRC
L
120 VAC
N
10 - HYDRONIC PIPING
24VAC FROM
TRANSFORMER
120VAC TO
TRANSFORMER
RELAY
24VAC COIL
120VAC CONTACTS
TO OIL
BURNER
INDIRECT WATER
HEATER, AQUASTAT
OR THERMOSTAT
TANK
CONTROL
C
24 VAC
R
TO DPM-2
X X
STATUS
PRIORITY ON
PRIMARY PUMP
PRIORITY PUMP
X-X CONTACT
ZR ON
L
120 VAC
TO XFRM
N
PRIMARY PRIORITY
120VAC FROM BOILER
PUMP PUMP
N L L N L N ZR ZC
AZ-4CP
1
PRI ZONE 1
CIRC
DHW ZONE
VALVE
27
ON
T-STAT
T-STAT T-STAT
T T T T T T T T
Z1 Z2 Z3
ZONE VALVE / PUMP
PRIORITY
ZR-ZC
DPM-2
ZC ON
OPTION SWITCHES
2 3 4 1 2 3 4 1 2 3 4 1 2 3
ZONE 2 ZONE 3 ZONE 4
ZONE ZONE
VALVE VALVE
ZONE
VALVE
ZONE VALVE / PUMP
PRIORITY
ZR-ZC
DPM-2
OPTION SWITCHES
KEY
ON
OFF
Z4
4