Instructions / Assembly

120 VOLT CIRCULATORS
ZC ZR
X X
ISOLATED
END SWITCH
120 VOLT
INPUT
120 VAC INPUT
TO: "TT" ON BOILER
ZONE1 ZONE2 ZONE3 ZONE4 ZONE5 ZONE6
PRIORITY
JUMPER
H N H N H N H N H N H N
ZONE1 ZONE2 ZONE3 ZONE4 ZONE5 ZONE6
PRIORITY
THERMOSTATS
SPARE
FUSE
120V RELAY
SPARE
FUSE
SIX ZONE
SWITCHING RELAY WITH PRIORITY
ZONE6
PRIORITY
ON
OFF
N H
SR 506
24 VAC
POWER
120 VOLT CIRCULATORS
ZC ZR
X X
ISOLATED
END SWITCH
120 VOLT
INPUT
120 VAC INPUT
TO "ZC" ON AQUASTAT
ZONE1 ZONE2 ZONE3 ZONE4 ZONE5 ZONE6
PRIORITY
H N H N H N H N H N H N
ZONE1 ZONE2 ZONE3 ZONE4 ZONE5 ZONE6
PRIORITY
THERMOSTATS
SPARE
FUSE
SPARE
FUSE
ZONE6
PRIORITY
ON
OFF
N H
TO "ZR" ON AQUASTAT
JUMPER
SIX ZONE
SWITCHING RELAY WITH PRIORITY
SR 506
120V RELAY
24 VAC
POWER
Operation: When any thermostat calls for heat, the appropriate circu-
lator is energized and the isolated end switch (X and X) will start the
boiler.
Priority Operation: When zone 6 is switched to the priority setting
and is actuated, all other zones will stop operation until zone 6 is sat-
isfied. When zone 6 is not switched to priority, all zones will operate
independently.
Jumper Placement: The jumper should be placed between terminals
ZC and ZR. Connect the isolated end switch to the aquastat control on
the boiler.
Power Input: Connect 120 volt ac power input to terminals N and H.
Neutral wire to terminal N. Hot wire to terminal H.
Operation: When any thermostat calls for heat, the boiler is given a
signal to start. The appropriate circulator is energized only when the
boiler temperature is above the set low limit.
Priority Operation: When zone 6 is switched to the priority setting
and is actuated, all other zones will stop operation until zone 6 is sat-
isfied. When zone 6 is not switched to priority, all zones will operate
independently.
Jumper Placement: MOVE
the jumper between terminals ZC and ZR to
end switch X and ZC. Connect terminal ZC to ZC terminal on the aqua-
stat control. Connect the other end switch X to ZR terminal on the
aquastat control. Confirm polarity is consistent between boiler aquastat
and switching relay
Power Input: Connect 120 volt ac power input to terminals N and H.
Neutral wire to terminal N. Hot wire to terminal H.
The Taco Connection:
Combine the reliability of the Taco Zone Valves, Priority Zoning
Circulators, Thermostats, and the “00” family of circulators with the
advanced features of the Taco Zone Controls to achieve total system
integration. No matter the application, Taco now provides the products
to maximize system performance while simplifying both installation
and service.
External Diagnostics:
Externally visible lights show full functionality of the switching relay.
The green light should always be on, indicating that power is connected.
When the thermostat calls for heat, both the appropriate circulator and
red indicating light is energized.
Warning: Wiring connections must be made in accordance with all applicable electrical
codes. Use copper wire only with a minimum temperature rating of 60/75°C. Failure to
follow this instruction can result in personal injury or death and/or property damage. 12-18
gauge wire recommended for 120 VAC connections, 14-22 gauge wire for thermostat con-
nections, and 14-22 gauge wire for 24 VAC source connections.
Cold Start Boiler
Application
Tankless Coil Boiler
Application
(Alternative Wiring)
Specifications:
PRODUCT NUMBER TRANSFORMER MAXIMUM DIMENSIONS OF ENCLOSURE
NUMBER OF ZONES VOLTAGE COMBINED LOAD WIDTH HEIGHT DEPTH
SR506 6 with Priority 120 VAC Input 20 amps 11 3/4" 7 1/2" 3"
All Switching Relays are relay type DPST, have a thermostat current of .18, and have a single phase
motor rating per zone of 1/3 hp (5.0A) fused @ 120 VAC.
Instruction Sheet
SR506 Switching Relay
102-165
SUPERSEDES: New EFFECTIVE: June 1, 2006
Plant ID# 9300-2090
Features: External Indicator Lights
Switchable Priority
Simplified Wiring
Fully Enclosed Snap-Out Relays
Fuse Protected Outputs
Compact Design
100% Factory Tested
Isolated End Switch
Contractor Friendly PC Board Layout
Universal Thermostat Compatibility
UL Approved
24 volt Power Input or Output Terminal
Extended 3 Year Warranty
Made in the USA
Warning: When using Alternative Wiring diagram, wiring instructions must be followed so power originates from the boiler aquastat. Failure to
follow these wiring instructions may result in a secondary source of power being connected to the boiler that may activate it under certain cir-
cumstances, causing injury or death.