Introduction
This manual provides essential instructions for the installation, operation, and maintenance of the Taco SR506-EXP-4 6-Zone Expandable Switching Relay. This device is designed to manage multiple heating zones in HVAC systems, offering advanced features for customization and efficient control.
The SR506-EXP-4 combines clearly-labeled PC board layouts with features that allow for system customization. It supports basic priority switching, Taco Plug-In PowerPort Cards, and add-on power controls. External indicator lights provide diagnostic feedback. All switching relays are UL listed, use standard "ice cube" replaceable relays, and are compatible with conventional and programmable thermostats.
For larger installations, this switching relay can be expanded up to 20 zones with priority. It can also interface with Boiler Reset Control and Injection Mixing Add-On Power Controls.
Safety Information
WARNING: Installation and servicing of this product must be performed by qualified personnel. Disconnect power before installing or servicing to prevent electrical shock or equipment damage. All wiring must comply with local electrical codes and regulations.
Read all instructions carefully before proceeding with installation or operation.
Setup and Installation
The Taco SR506-EXP-4 is designed for simplified wiring and installation. Professional installation is recommended to ensure proper functionality and safety.
Mounting
- Select a suitable location for mounting the relay, typically near the boiler or heating system, ensuring it is protected from moisture and extreme temperatures.
- Mount the unit securely using appropriate fasteners. The unit dimensions are approximately 11.75 x 3 x 7.5 inches.
Wiring
- Ensure all power is disconnected before beginning any wiring.
- Connect the main power supply to the designated terminals on the relay board.
- Connect each zone thermostat to its corresponding zone terminal on the relay. The SR506-EXP-4 supports six zones.
- Connect the zone pumps or zone valves to the appropriate terminals for each zone.
- Connect the boiler control wiring to the main end switch terminals.
- Refer to the clearly labeled PC board layout for specific wiring connections.
Figure 1: Front view of the Taco SR506-EXP-4 Switching Relay. This image displays the green enclosure, indicator lights for power and six zones, and the product label detailing the model number and zone configuration.
Power-Up
- Once all wiring is complete and verified, restore power to the unit.
- Observe the external indicator lights for instant diagnostic feedback during start-up. The Power light should illuminate.
Operating Instructions
The Taco SR506-EXP-4 operates in conjunction with thermostats and the heating system to manage zone heating.
Zone Control
- When a thermostat in a specific zone calls for heat, the corresponding zone indicator light on the relay will illuminate.
- The relay will then activate the associated zone pump or valve and signal the boiler to fire, if necessary.
- The SR506-EXP-4 features switchable priority, allowing one zone to take precedence over others when multiple zones call for heat simultaneously. Consult the detailed wiring diagram for priority setup.
Expandability
The system can be expanded up to 20 zones by connecting additional compatible Taco switching relays. Refer to the expansion wiring diagrams for proper configuration.
PowerPort Cards
Optional Taco PowerPort Plug-In Cards can be used to add features such as post purge, priority protection, and pump exercise. Install these cards into the designated slots on the relay board according to their specific instructions.
Maintenance
The Taco SR506-EXP-4 is designed for reliable operation with minimal maintenance.
- Regular Inspection: Periodically inspect the unit for any signs of damage, loose connections, or excessive dust accumulation.
- Cleaning: Ensure the unit is kept clean and free of dust. Use a soft, dry cloth for cleaning. Do not use liquid cleaners.
- Relay Replacement: The unit uses standard "ice cube" replaceable relays. If a relay fails, disconnect power, carefully remove the faulty relay, and insert a new, compatible relay.
- Professional Servicing: For any complex issues or internal component servicing, contact a qualified HVAC technician.
Troubleshooting
This section provides guidance for common issues. For persistent problems, consult a qualified technician.
| Problem | Possible Cause | Solution |
|---|---|---|
| No Power Indicator Light | No power to the unit; faulty wiring; blown fuse (if applicable). | Check power supply to the relay. Verify all power wiring connections. Consult an electrician if necessary. |
| Zone Not Activating (No Heat) | Thermostat not calling for heat; faulty thermostat; wiring issue to zone; faulty zone pump/valve; faulty relay. | Check thermostat setting and functionality. Verify wiring for the specific zone. Check zone pump/valve operation. Observe zone indicator light on the relay; if it's on but no heat, check pump/valve. If off, check thermostat/wiring. |
| Boiler Not Firing | Main end switch wiring issue; boiler control problem; multiple zones calling with priority issues. | Verify main end switch wiring to the boiler. Ensure boiler is operational. Check priority settings if multiple zones are active. |
| Intermittent Operation | Loose wiring connections; power fluctuations; failing relay. | Inspect all wiring connections for tightness. Ensure stable power supply. Consider replacing individual zone relays if issues persist for a specific zone. |
Specifications
| Feature | Detail |
|---|---|
| Model Number | SR506-EXP-4 |
| Brand | Taco |
| Number of Zones | 6 (Expandable up to 20) |
| PowerPoints | 3 |
| Mounting Type | Plug In Mount |
| Relay Type | Standard "ice cube" replaceable relays |
| Contact Type | Normally Open |
| Contact Material | Silver |
| Product Dimensions | 11.75 x 3 x 7.5 inches |
| Weight | 3.25 Pounds |
| Certifications | UL Listed |
| Compatibility | Conventional and programmable thermostats |
Warranty and Support
For specific warranty information regarding the Taco SR506-EXP-4 Switching Relay, please refer to the documentation provided with your purchase or contact Taco, Inc. directly. Warranty terms typically cover manufacturing defects for a specified period from the date of purchase.
For technical support, installation assistance, or to inquire about replacement parts, please contact Taco customer service or visit their official website. It is recommended to have your product model number (SR506-EXP-4) and purchase details available when seeking support.
Manufacturer: Taco, Inc.
Website: www.tacocomfort.com
