Taco Instruction Sheet
SR506 Switching Relay
Supersedes: 102-085 December 1, 1999
Plant ID# 9300-834
Effective: October 15, 2005
Cold Start Boiler Application
Diagram showing wiring for a cold start boiler application with a Taco SR506 Switching Relay. It illustrates connections for thermostats, circulators, power input, and an isolated end switch.
Warning: Wiring instructions must be followed to prevent injury or death. Incorrect wiring may result in a secondary power source activating the boiler.
Operation: When a thermostat calls for heat, the appropriate circulator energizes, and the isolated end switch starts the boiler.
Priority Operation: Zone 6, when set to priority and actuated, will stop other zones until satisfied. If not set to priority, all zones operate independently.
Jumper Placement: Place jumper between terminals ZC and ZR. Connect the isolated end switch to the boiler's aquastat control.
Power Input: Connect 120 VAC to terminals N (Neutral) and H (Hot).
Tankless Coil Boiler Application
Diagram showing wiring for a tankless coil boiler application with a Taco SR506 Switching Relay. It illustrates connections for thermostats, circulators, power input, and an isolated end switch.
Operation: When a thermostat calls for heat, the boiler and circulator energize if the boiler temperature is above the set low limit.
Priority Operation: Zone 6, when set to priority and actuated, will stop other zones until satisfied. If not set to priority, all zones operate independently.
Jumper Placement: Move jumper between ZC and ZR to end switch X and ZC. Connect ZC to the aquastat control's ZC terminal. Connect end switch X to the aquastat control's ZR terminal. Ensure polarity consistency.
Power Input: Connect 120 VAC to terminals N (Neutral) and H (Hot).
The Taco Connection
Taco Zone Valves, Priority Zoning Circulators, Thermostats, and "00" family circulators integrate with Taco Zone Controls for optimal system performance and simplified installation and service.
External Diagnostics
Externally visible lights indicate functionality. A green light signifies power. When a thermostat calls for heat, the circulator and red indicator light energize.
Specifications
| Product Number | Number of Zones | Transformer Voltage | Maximum Combined Load | Dimensions of Enclosure (Width x Height x Depth) | |
|---|---|---|---|---|---|
| SR506 | 6 with Priority | 120 VAC Input | 20 amps | 11 3/4" | 7 1/2" x 3" |
All Switching Relays are DPST type, with a thermostat current of 0.18A, and a single-phase motor rating per zone of 1/3 hp (7.2A) @ 120 VAC.
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 Approved
- 24 volt Power Input or Output Terminal
- Extended 3 Year Warranty
- Made in the USA
Warning: Wiring connections must comply with all applicable electrical codes and instructions. Use copper wire only. Failure to do so may result in personal injury, death, or property damage. Recommended wire gauges: 10-18 AWG for 120 VAC (9 in-lbs torque max), 12-22 AWG for thermostat connections (9 in-lbs torque max), and 12-22 AWG for 24 VAC (5 in-lbs torque max).
