Brochure

FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
ZONE 4
ON
OFF
PRIORITY
120V RELAY
FUSE 1 AMP
24 VAC
POWER
MASTER
1234
PLUG-IN CARDS
RESET NORMAL
SLAVE
POWER
CONTROL
INTERFACE
THERMOSTATS
ZONE 1 ZONE 2 ZONE 3 ZONE 4
120 VAC INPUT
TO: "TT" ON BOILER
120 VOLT CIRCULATORS
ZC ZR
X X
END
SWITCH
ZONE1 ZONE2 ZONE3 ZONE4
POWER
INPUT
SR 504-EXP
ZONE 2
POWER
ZONE 1
ZONE 3
ZONE 4
JUMPER
FOUR ZONE SWITCHING RELAY
WITH OPTIONAL PRIORITY
120V RELAY
FUSE 1 AMP
24 VAC
POWER
ZONE 4
ON
OFF
PRIORITY
MASTER
1234
PLUG-IN CARDS
RESET NORMAL
SLAVE
POWER
CONTROL
INTERFACE
120 VAC INPUT
THERMOSTATS
120 VOLT CIRCULATORS
ZC ZR
X X
END
SWITCH
ZONE1 ZONE2 ZONE3 ZONE4
POWER
INPUT
ZONE 1 ZONE 2 ZONE 3 ZONE 4
SR 504-EXP
ZONE 2
POWER
ZONE 1
ZONE 3
ZONE 4
TO: "ZC" ON AQUASTAT
TO: "ZR" ON AQUASTAT
JUMPER
Cold Start Tankless
Switching Relays
Product Number Transformer Maximum Dimensions of Enclosure
Number of Zones Voltage Combined Load Width Height Depth
SR501 1 Zone 120 VAC Input 5 amps 4 1/4” 5 1/4” 2 3/4”
SR502 2 with Priority 120 VAC Input 15 amps 10 1/4” 6 3/4” 2 3/4”
SR503 3 with Priority 120 VAC Input 15 amps 10 1/4” 6 3/4” 2 3/4”
SR504 4 with Priority 120 VAC Input 20 amps 10 1/4” 6 3/4” 2 3/4”
SR506 6 with Priority 120 VAC Input 20 amps 11 3/4” 7 1/2” 3”
Switching Relays with PowerPort Option
Product Number PowerPort Power Control Transformer Maximum Dimensions of Enclosure
Number of Zones Slots Plugs Voltage Combined Load Width Height Depth
SR501-EXP 1 Zone 0 1 120 VAC Input 5 amps 4 1/4” 5 1/4” 2 3/4”
SR503-EXP 3 with Priority 3 1 120 VAC Input 20 amps 10 1/4” 6 3/4” 2 3/4”
SR504-EXP 4 with Priority 3 1 120 VAC Input 20 amps 10 1/4” 6 3/4” 2 3/4”
SR506-EXP 6 with Priority 3 1 120 VAC Input 20 amps 11 3/4” 7 1/2” 3”
All Switching Relays are relay type DPDT, have a thermostat current of .18, and have a single phase motor rating per zone of 1/3 hp (5 A) @ 120 VAC.
Plug-in PowerPort Cards* Add-on Power Controls*
PC600 Post Purge Timer Plug-in Card PC700 Boiler Reset Control
PC605 Priority Protection Plug-in Card PC702 Two Stage Boiler Reset Control
PC610 Universal Timer / Pump Exercise Plug-in Card PC705 Variable Speed Pump Injection Mixing Control
*For use with -EXP controls.
Switching Relays
Taco Switching Relays combine clearly labeled PC board layouts with advanced features that allow
for total system customization. Whether using basic priority switching or the advanced features
of the -EXP controls, the job is made easy. External indicator lights provide instant diagnostic
feedback, making a snap of service calls or new installation start-ups. All switching relays are UL
and CSA listed, use standard “ice cube” replaceable relays and are compatible with conventional
and programmable thermostats.
Taco Expandable Switching Relays
Whether you want to expand up to 20 zones or utilize the advanced features of the PowerPort
Cards and Add-on Power Controls, Taco -EXP controls allow for simple integration of advanced
features. Plug in any combination of cards and controls to optimize the operation of any system.
Wiring Diagram
Features
External Indicator Lights
Switchable Priority
Simplified Wiring
Fully Enclosed Snap-Out Relays
Compact Design
Fuse Protected
100% Factory Tested
Isolated End Switch
Contractor Friendly PC Board Layout
Universal Thermostat Compatibility
UL and CSA Approved
24 Volt Power Input or Output Terminal
Extended 3 Year Warranty
Made in the USA
Additional -EXP Features
Plug-in PowerPort Card Slots
Add-on Power Control Plug
Expandable to 20 Zones
Interface with -EXP Zone Valve Controls
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
It’s no longer necessary to open the box
to troubleshoot the system. 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.
Submittal Data # 101-052 Effective: 07/11/07
Supersedes: 12/01/00
Submittal Data Information
Switching Relay
Taco Inc., 1160 Cranston Street, Cranston, RI 02920 / [phone] / Fax [phone]
Taco (Canada) Ltd., 6180 Ordan Drive, Mississauga, Ontario L5T 2B3 / [phone] / Fax [phone]
www.taco-hvac.com
Cold Start Boiler
Application
Tankless Coil Boiler
Application