Wiring Guide
SR501-EXP Switching Relay Controlling a Zone Valve Control
TO BOILER AQUASTAT RELAY
BOILER
H
N
BOILER TURNS ON WHEN ANY ZONE VALVE OPENS.
120 VAC
INPUT
TO BOILER AQUASTAT RELAY
SLAVE
SYSTEM PUMP TURNS ON WHEN ANY ZONE VALVE OPENS
EXCEPT WHEN THE DHW HEATER (SR501-EXP) CALLS.
MASTER
POWER
ZONE 1
LED
INDICATORS
FUSE
6 AMP
FUSE
6 AMP
SR 501-EXP-4
POWER
CONTROLS
SLAVE
PRIORITY ON
RESET
PRIMARY PUMP ON
POST PURGE ON
PRIORITY PROTECT ON
PUMP EXERCISE ON
30 SEC/2 WK
MASTER
OFF
OFF
OFF
OFF
OFF
NORMAL
4 MIN/24 HOUR
ACCESSORY
PORT
DHW HEATER
CIRCULATOR
HN/O N H
120 VAC
CIRCULATOR
PRIMARY
OUTPUT
N/C
INPUT
120 VAC
END
SWITCH
RESET
OVERRIDE
THERMOSTATEXPANSION
X
W
R
X1A2CB
24 VOLTS AC ONLY
C
SINGLE ZONE
EXPANDABLE SWITCHING RELAY
120 VAC INPUT
1234
ZONE 1
1234
ZONE 2
1234
ZONE 3
1234
ZONE 4
1234
ZONE 5
1234
ZONE 6
PRIORITY
ZONE
2 WIRE ZONE VALVE
(NO END SWITCH)
MUST USE JUMPER
TACO
3 WIRE
ZONE VALVE
1
2
3
JUMPER
3 & 4
MOTOR END
SWITCH
4 WIRE ZONE VALVE
(POWER OPEN,
SELF CLOSING)
JUMPER
3 & 4
ZVC 406 – 4
SIX ZONE
ZONE VALVE CONTROL
24 VAC
FACTORY
INSTALLED
TRANSFORMER
120 VAC
INPUT
WHITE
BLACK
POWER IN
24 VAC
24 VAC
FACTORY
INSTALLED
TRANSFORMER
120 VAC
INPUT
WHITE
BLACK
DRY
CONTACTS
N/O
COM
N/C
PUMP END
SWITCH
ZONE 6 PUMP
END SWITCH
THERMOSTATS (24VAC)
T STAT 1
VALVE 1
T STAT 2
VALVE 2
T STAT 3
VALVE 3
T STAT 4
VALVE 4
VALVE 5
T STAT 6
VALVE 6
POWER
LED
INDICATORS
T STAT 5
ZONE 1 ZONE 2 ZONE 3 ZONE 4 ZONE 5 ZONE 6
ISOLATED
XX
END SWITCH THERMOSTATS (24 VAC) PRIORITY
24 VAC ZONE VALVES PRIORITY
XX
ZONE 6
PRIORITY
OFF
ON
NOTE 2: When a circulator
is used on the priority zone
instead of a zone valve,
jumper 3 and 4 of the
priority zone.
FUSE
5 AMP
RW
See NOTE 1
RW
RW RWCCC
RW
C
C
FUSE
5 AMP
RW
C
Powered from Transformer
A Powered from Transformer B
A
B
Powered from Transformer A Powered from Transformer B
SYSTEM
PUMP
T
TT
INDIRECT
WATER HEATER
AQUASTAT OR
THERMOSTAT
PRIORITY
ON
NOTE 1: Terminals C are for
optional 24V thermostat
COMMON connections.
11