Instruction Sheet - Sr501-Exp Switching Relay - Taco SR501 Wiring Manual

Cold Start Boiler
Application
THERMOSTAT
TO: "TT" on Boiler Aquastat
POWER
CONTROLS
END
SWITCH
X X 1
K1-A
FUSE
1 AMP
SR 501-EXP
TO: 120 VAC POWER
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.
Operation: When the thermostat calls for heat, the appropriate circulator is ener-
gized and the isolated end switch (X and X) will start the boiler. Priority Output
has power all the time, except when the thermostat is calling.
Mode Operation: When the mode switch is set to NORMAL, the end switch
relay will be energized if any zone is in operation. When the switch is set to
RESET, the end switch relay will only be energized through the operation of a
plug-in reset control or closure of Priority Input.
Jumper Placement: The jumper should be placed between terminals ZC and H.
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.
Expansion Connections: Set the expansion switch to MASTER on the switching
relay that has the designated priority zone or is utilizing the PowerPort options.
Set all other daisy chained controls to SLAVE. Connect thermostat wire (18-22
gauge) between terminals 1, 2, 3, 4 on the master control to the corresponding
1, 2, 3, 4 on the SLAVE control(s). Controls may be daisy chained up to 20 zones
using any combination of -EXP controls.
Features: External Indicator Lights
Ideal for Retrofitting
Priority Output
Simplified Wiring
Add-On Power Controls
Sealed Relays
Compact Design
Fuse Protected
100% Factory Tested
Isolated End Switch
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 connections, and 14-22 gauge wire for 24 VAC source
connections.
Do it Once. Do it Right.
TACO, INC., 1160 Cranston Street, Cranston, RI 02920
TACO (Canada), Ltd., 6180 Ordan Drive, Mississauga, Ontario L5T 2B3.
Visit our web site at: http://www.taco-hvac.com
SR501-EXP Switching Relay
T
TO: DHW Aquastat if PC700
Boiler Reset is installed.
MODE
RESET
EXPANSION THERMOSTAT
RESET
OVERRIDE
2 3 4 1 2
T/R T/W COM
MASTER
NORMAL
K1 K2
SLAVE
POWER
T STAT
FUSE
5 AMP
K1-B K2-A K2-A
N H ZC ZR H H
POWER
120VAC 120VAC CIRC PRIORITY
INPUT INPUT OUTPUT OUTPUT OUTPUT
JUMPER
CIRCULATOR
Expandable to 20 Zones
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
®
Instruction Sheet
Tankless Coil Boiler
Application
TO: ZC on Boiler Control
TO: ZR on Boiler Control
TO: 120 VAC POWER
Operation: When the thermostat calls for heat, the appropriate circulator is ener-
gized when the boiler's aquastat is above the set low limit. The ZR (120VAC) out-
put will signal the boiler to start. Priority Output has power all the time, except
when the thermostat is calling.
Mode Operation: When the mode switch is set to NORMAL, the end switch
relay will be energized if any zone is in operation. When the switch is set to
RESET, the end switch relay will only be energized through the operation of a
plug-in reset control or closure of Priority Input.
Jumper Placement: REMOVE the jumper between terminals ZC and H. Connect
terminal ZC to ZC terminal on the aquastat control. Connect terminal ZR 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.
Expansion Connections: Set the expansion switch to MASTER on the switching
relay that has the designated priority zone or is utilizing the PowerPort options.
Set all other daisy chained controls to SLAVE. Connect thermostat wire (18-22
gauge) between terminals 1, 2, 3, 4 on the master control to the corresponding
1, 2, 3, 4 on the SLAVE control(s). Controls may be daisy chained up to 20 zones
using any combination of -EXP controls.
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 are energized.
Specifications:
PRODUCT NUMBER
NUMBER OF ZONES
SR501-EXP 1
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 (5.0A) @ 120 VAC.
Telephone: (401) 942-8000 FAX: (401) 942-2360.
Telephone: 905/564-9422.
THERMOSTAT
T
POWER
CONTROLS
END
EXPANSION THERMOSTAT
SWITCH
X X 1 2 3 4
T/R T/W COM
FUSE K1-A
MASTER
1 AMP
K1
SLAVE
FUSE
5 AMP
K1-B
N H ZC ZR
POWER
120VAC 120VAC
INPUT INPUT OUTPUT
SR 501-EXP
POWER TRANSFORMER MAXIMUM
CONTROLS VOLTAGE COMBINED LOAD
1 120 VAC Input 5.0 amps
FAX: 905/564-9436.
TO: DHW Aquastat if PC700
Boiler Reset is installed.
MODE
RESET
RESET
OVERRIDE
1 2
NORMAL
K2
POWER
T STAT
K2-A K2-A
H H
CIRC PRIORITY
OUTPUT OUTPUT
CIRCULATOR
DIMENSIONS OF ENCLOSURE
WIDTH HEIGHT DEPTH
4 1/4" 5 1/4" 2 3/4"
Printed in USA
Copyright 2005
TACO, Inc.
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