Installation Guide
56
3 Wire Thermostat Connected to TACO Non-Expandable Switching Relay
TO: "TT"
ON BOILER
H
N
120 VAC
INPUT
FOUR ZONE SWITCHING RELAY
120 VAC CIRCULATORS
ZC
INPUT
120 VAC
ZONE 1 ZONE 2 ZONE 3 ZONE 4
ZONE1
ZONE2
ZONE3
SR 504-4
FUSE
6
AMP
FUSE
6
AMP
FUSE
6
AMP
FUSE
6
AMP
FUSE
6
AMP
X
X
R
W
R
W
R
W
R
W
ISOLATED
END
SWITCH
THERMOSTATS (24 VAC)
P
RIORITY
120 VAC
ZR
HHNHNHNHNH NH
ZONE4
Z
ONE 2
POWER
Z
ONE 1
Z
ONE 3
ZONE 4
LED
I
NDICATORS
Z
ONE 4
P
RIORITY
OFF
O
N
P
RIORITY
2
4 VAC
C
OM
BOILER
JUMPER
T
T
T
THERMOSTATS
T
3
WIRE
THERMOSTAT
COM
Power Stealing Thermostat Wiring
May Need To Connect 1000 (1K) Ohm 1/2 Watt Resistor Between W and C
TO: "TT"
ON BOILER
H
N
120 VAC
INPUT
FOUR ZONE SWITCHING RELAY
120 VAC CIRCULATORS
ZC
INPUT
120 VAC
ZONE 1 ZONE 2 ZONE 3 ZONE 4
ZONE1
ZONE2
ZONE3
SR 504-4
FUSE
6 AMP
FUSE
6 AMP
FUSE
6 AMP
FUSE
6 AMP
FUSE
6 AMP
XX
RW
RW
RW
RW
ISOLATED
END
SWITCH
THERMOSTATS (24 VAC)
PRIORITY
120 VAC
ZR
HHNHNHNHNH NH
ZONE4
ZONE 2
POWER
ZONE 1
ZONE 3
ZONE 4
LED
INDICATORS
ZONE 4
PRIORITY
OFF
ON
PRIORITY
24 VAC
COM
BOILER
JUMPER
T
T
T
THERMOSTATS
T
2 WIRE POWER STEALING
THERMOSTAT
1000 Ohm (1K) 1/2 Watt Resistor
COM
RW
24
VAC
TT
THERMOSTAT
1000 Ohm (1K)
1/2 Watt Resistor










