If you’re planning to install or replace a Taco switching relay, it’s essential to understand how it works and what the wiring diagram looks like. In this article, we’ll guide you through the process of wiring a Taco switching relay and answer some frequently asked questions about this popular product. Let’s dive in!
What is a Taco Switching Relay?
A Taco switching relay is a device that allows you to control multiple heating and cooling zones from a single thermostat. It’s commonly used in residential and commercial HVAC systems to improve energy efficiency and comfort. The switching relay works by receiving signals from a thermostat and activating the appropriate zone valve, circulator pump, or other HVAC component.
The Taco switching relay is available in various models, including the SR503, SR501, and SR506. Each model has unique features and specifications, but they share a similar wiring diagram. Let’s take a closer look at the wiring diagram of the Taco SR503 switching relay.
Taco SR503 Wiring Diagram
The Taco SR503 switching relay has a straightforward wiring diagram that consists of six zones, a priority zone, and a power supply. Here’s a table that summarizes the terminals and components in the SR503 switching relay:
| Terminal | Description |
|---|---|
| T T | Thermostat terminals |
| ZC ZR | Zone control terminals |
| P | Priority zone terminal |
| X X | Power input terminals |
| SR 503-EXP | Expandable switching relay terminal |
Now, let’s see how to wire a Taco SR503 switching relay.
How to Wire a Taco SR503 Switching Relay
To wire a Taco SR503 switching relay, you’ll need the following components:
- A Taco SR503 switching relay
- A transformer (if not included in the switching relay)
- Zone valves or circulator pumps
- Thermostat cable
- Wire connectors
Here’s a step-by-step guide on how to wire a Taco SR503 switching relay:
Step 1: Mount the Switching Relay
Mount the Taco SR503 switching relay on a flat surface or a panel using the mounting screws provided. Make sure to follow the manufacturer’s instructions for proper installation and grounding.
Step 2: Connect the Power Supply
Connect the power supply to the X X terminals of the Taco SR503 switching relay. The voltage rating of the power supply should match the specifications of the switching relay. If the transformer is not included in the switching relay, wire the transformer’s primary coil to an AC power source and the secondary coil to the X X terminals.
Step 3: Connect the Thermostat
Connect the thermostat cable to the T T terminals of the Taco SR503 switching relay. The cable should have at least three wires: one for power, one for heat, and one for cooling. Follow the color codes or markings on the cable and the terminals.
Step 4: Connect the Zone Valves or Circulator Pumps
Connect the zone valves or circulator pumps to the ZC ZR terminals of the Taco SR503 switching relay. The number of zones may vary depending on the model and configuration of the switching relay. Follow the manufacturer’s instructions for proper valve or pump wiring.
Step 5: Connect the Priority Zone
Connect the priority zone valve to the P terminal of the Taco SR503 switching relay. The priority zone valve is typically used for domestic hot water or other high-priority applications. Follow the manufacturer’s instructions for proper valve wiring.
Step 6: Test the System
Once you’ve wired the Taco SR503 switching relay, test the system to make sure it’s working correctly. Set the thermostat to the desired temperature and observe if the valves or pumps are activating correctly. Make any necessary adjustments, and you’re good to go!
Frequently Asked Questions
What is the difference between a Taco SR503 and SR506?
The main difference between the Taco SR503 and SR506 switching relays is the number of zones they support. The SR503 supports up to three zones, while the SR506 supports up to six zones. Additionally, the SR506 has an optional outdoor reset control and a diagnostic LED display, which the SR503 lacks.
Can I wire multiple thermostats to a Taco switching relay?
Yes, you can wire multiple thermostats to a Taco switching relay by connecting them to the T T terminals. Each thermostat should have a separate wire for power, heat, and cooling. Make sure to follow the manufacturer’s instructions for proper wiring and configuration.
What is the purpose of the priority zone in a Taco switching relay?
The purpose of the priority zone in a Taco switching relay is to provide hot water or heating to a specific area or appliance, such as a shower or dishwasher. The priority zone valve is typically wired to the P terminal and activated when needed, overriding the other zones’ demand.
Can I use a Taco switching relay with a heat-only system?
Yes, you can use a Taco switching relay with a heat-only system by wiring the thermostat cable to the T T terminals and the zone valve or circulator pump to the ZR terminal. The ZC terminal is not used in heat-only systems. Make sure to follow the manufacturer’s instructions for proper wiring and configuration.
What is the warranty for a Taco switching relay?
The warranty for a Taco switching relay varies depending on the model and the place of purchase. Typically, it ranges from one to three years for residential applications and one year for commercial applications. Make sure to check the warranty terms and conditions before buying or installing a Taco switching relay.
Conclusion
Wiring a Taco switching relay is not rocket science, but it requires some basic knowledge of HVAC systems and electrical wiring. By following the wiring diagram and the manufacturer’s instructions, you can install or replace a Taco switching relay with confidence and benefit from its energy-saving and comfort-enhancing features. We hope this article has helped you understand the Taco switching relay wiring diagram and answered some of your questions about this versatile device. If you have any other questions or comments, feel free to contact us!
