Taco SR501-4 Switching Relay Instruction Manual
- October 30, 2023
- TACO
Table of Contents
Taco SR501-4 Switching Relay Instruction
Product Information
The SR501 Switching Relay is designed to control two SR504/506 Switching
Relays. It is a one-zone switching relay with LED indicators that show power
and zone 1. The input voltage is 120VAC, and it has two 6-amp fuses. It has a
jumper for DHW circulator and thermostat slave priority. The product also
comes with replacement switching relay fuses and an optional power stealing
thermostat resistor. The SR504-4 Switching Relay is a four-zone switching
relay with LED indicators that show power, zone 1, zone 2, zone 3, and zone 4.
It has five 6-amp fuses, and the input voltage is 120VAC. It also has a jumper
for DHW circulator and thermostat slave priority. The product comes with a
limited warranty statement from Taco,
Inc. that covers any product or part proven defective under normal use within
three years from the date of start-up or three years and six months from the
date of shipment, whichever occurs first. The warranty does not cover products
or parts that have been subject to misuse, misapplication, or abuse.
Product Usage Instructions
Before using the product, make sure to read the user manual and follow the instructions carefully. Here are some general usage instructions:
- Connect the SR501 Switching Relay to two SR504/506 Switching Relays to control them.
- Switch on the AQUASTAT and DHW HEATER.
- Use the MASTER switch to control the SR 501-4.
- Connect the R, W, and 24 VAC wires to the appropriate terminals.
- Connect the T and T COM wires to the appropriate terminals.
- Use the LED indicators to monitor power and zone 1.
- Use a 6-amp fuse for the product.
- Connect the NH3 wires to the appropriate terminals.
- Connect the N/C, N/O, and COM wires to the appropriate terminals.
- Connect the TT ON BOILER wires to the appropriate terminals.
- Use a jumper for DHW circulator and thermostat slave priority. Use the isolated end for ZONE 1, ZONE 2, ZONE 3, and ZONE 4.
- Switch on or off the priority for the zone using the PRIORITY switch.
- Use a 120VAC input for the product.
- Use a 24 VAC thermostat to control the product.
- Use a fused com for the product.
- Use the X, R, W, WR, and H wires to connect the product to other devices.
- Remove the jumper for SR504-4 Switching Relay.
- Use a 120VAC input for the product.
If you have any doubts about whether a particular substance is suitable for use with the product or for any application restrictions, consult the applicable Taco instruction sheets or contact Taco at [401-942-8000].
Instruction Sheet
SR501-4 Switching Relay
SUPERSEDES March 1, 2013
Plant 9300-2865
Features
- External Indicator Lights
- Universal Replaceability
- snap-in pc Board
- Simplified Wiring
- Sealed Relays
- Fuse protected Outputs
- 100th Factory Tested
- Contractor Friendly PC Board Layout
- Universal Thermostat Compatibility
- U I. Approved
- Extended 3 Year Warranty
OPERATION
- Connect a thermostat to the “T terminals on the switching relay. When the thermostat calls for heat, the relay is energized and power is given to the circulator.
power Input:
Connect 120 volt ac power to terminals N and H.
Jumper Placement:
The jumper is factory installed between ter- minals H and 3 to switch power on
terminals 4 n/o and 4 n/c.
Terminal Description
- T& T thermostat
- COM Connection Common side Of transformer, to power some setback thermostats
- N Neutral wire of power input
- H Hot Wire Of power input
- 3 Common terminal for
- 4 n/o Normally open terminal
- 4 n/c Normally closed terminal
- 6 n/c Normally closed terminal
- 6 n/o Normally open terminal
- 5 Common terminal for 6 n/o and 6
Specifications
WARNING : Wiring connections must be made in accordance with all
applicable electrical codes. Use copper wire only. 120 VAC wiring must have a
minimum temperature rating of 750C. Failure to follow this instruction can
result in personal injury or death and/or property damage. 12-18 gauge wire is
recommended for 120 VAC connections, 14-22 gauge wire for ther
mostat connections, and 14-22 gauge wire for 24 VAC source connections.
NOTE 2: When using the Alternative Wiring diagram, the boiler operating
control’s terminal will see the load of the circulator(s).
WARNING : When using the Alternative Wiring diagram, wiring instructions
must be followed so originates from the boiler aquastat. Failure to follow
these wiring instructions may result in a secondary source of power being
connected to the IN)iler that may activate it under certain circumstances,
causing injury or death.
Troubleshooting
- Problem: Digital thermostats do not work correctly when connected to a switching relay.
- Solution: Some thermostats are a “Power Stealing” which means they are powered by the switching relay with just 2 wires (R & W). A resistor may be needed in order to have the thermostat work properly. This resistor should be placed between the W & C (common) terminals of the switching relay. If the thermostat manufacturer does not supply a resistor, a 11M ohm watt resistor has proven to work with most models and is readily available at electronic supply outlets (e.g. Radio Shack). If the thermostat is battery [N) were, then check that the batteries are fresh and installed correctly.
- Problem: No heat in a zone or room of the building. LED diagnostic lights will help find a comment that is not
- Solution. working properly. The green LED should always be on, indicating that m) over is connected and the solid-state fuse is good. When there is a call for heat, the red LED will come on indicating [NM,ver to the zone circulator. This indicates the thermostat is working correctly. If the red LED does not come on, then check the thermostat and thermostat wiring for errors.
For information on Taco’s Switching Relays (SR) including catalog sheet, instruction sheets, Visio stencils and our highly praised Zone Controls Wiring Guide, scan the QR code to the right or go to our website: http://www.taco- hvac.com.
FCC Rules
This device complies with part 15 of the FCC Rules. Operation is subject to the following two con- ditions: (1) Th’s device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.
SR501 Switching Relay Controlling 2 SR504/506 Switching Relays
Replacement Switching Relay fuses part number: SR6A-001 RP (Manufacture:
Littlefuse, Part Number: 229006)
Optional power stealing thermostat resistor part number: SRTR-OOI RP
(Value: 1000 Ohms, 1/2 watt or higher)
LIMITED WARRANTY STATEMENT
Taco, Inc. will repair or replace without charge (at the company’s option) any
product or part which is proven defective under normal use within three (3)
years from the date of start-up or three (3) years and six (6) months from
date Of shipment (whichever occurs first). In order to obtain service under
this warranty, it is the responsibility of the purchaser to promptly notify
the local Taco stocking distributor or Taco in writing and promptly deliver
the subject prod- uct or part, delivery prepaid, to the stocking dis-
tributor. For assistance on warranty returns, the purchaser may either contact
the local Taco stocking distributor or Taco. If the subject prod- uct or part
contains no defect as covered in this warranty, the purchaser will be billed
for parts and labor charges in effect at time of factory examination and
repair. Any Taco product or part not installed or operat- ed in conformity
with Taco instructions or which has been subject to misuse, misapplication,
the addition of fluids or certain chemical additives to the systems, or other
abuse, will not covered by this warranty. If in doubt as to whether a
particular substance is suitable for use with a Taco product or part, or for
any application restrictions, consult the applicable Taco instruction sheets
or contact Taco at [401-942-8000]. Taco reserves the right to provide
replacement products and parts which are substantially sim- ilar in design and
functionally equivalent to the defective product or part. Taco reserves the
right to make changes in details of design, con- struction, or arrangement of
materials Of its products without notification.
TACO OFFERS THIS WARRANTY IN LIEU OF ALL OTHER EXPRESS WARRANTIES. ANY
WARRANTY IMPLIED BY LAW INCLUDING WARRANTIES OF MERCHANTABILITY OR FIT-NESS IS
IN EFFECT ONLY FOR THE DURATION OF THE EXPRESS WARRANTY SET FORTH IN THE FIRST
PARAGRAPH ABOVE. THE ABOVE WARRANTIES ARE IN LIEU OF ALL OTHER WARRANTIES,
EXPRESS OR STATUTORY, OR ANY OTHER WARRANTY OBLIGATION ON THE PART OF TACO.
TACO WILL NOT BE LIABLE FOR ANY SPE- CAL, INCIDENTAL, INDIRECT OR CONSE-
QUENTIAL DAMAGES RESULTING FROM THE USE OF ITS PRODUCTS OR ANY INCIDENTAL
COSTS OF REMOVING OR REPLACING DEFECTIVE PRODUCTS. This warranty gives the
purchaser specific rights, and the purchaser may have other rights which vary
from state to state. Some states do not allow limitations on how Bng an
warranty lasts or on the exclusion of incidental or consequential damages, so
these limitations or exclusions may not apply to you.
Taco, Inc., 1160 Cranston Street, Cranston, RI 02920 | Tel: (401) 942-8000 | FAX: (401) 942-2360 Taco 8450 Lawson Road, suite Milton, Ontario L9TOJ8 1 Tel: (905) 564-9422 | 564-9436 Visit our web site: www.TacoComfort.com I Printed in USA | 02015 Taco, Inc.