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TACOZone-Switching Relays

TACO Zone Switching Relay: Switching, 3 with Priority Zones, 0 Power Port Slots

The TACO SR503-5 is a zone-switching relay with 3 zones with priority, operating on a 120V AC primary supply. It supports a full-load amperage (FLA) of 20 A at 120V AC. This switching relay is designed for zone…

SKU 3G-OTH-67263

Also listed as: SR5035 · SR503 5

Brand
TACO
Item
Zone Switching Relay: Switching, 3 with Priority Zones, 0 Power Port Slots
Category
Zone-Switching Relays
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Delivery
Same-day or next-business-day delivery within Singapore for in-stock items; 7–14 days for factory-order parts from Europe.
Payment
Invoicing in SGD. PayNow, bank transfer, and corporate PO accepted.
Ships to
Singapore

Technical Specifications

TACO
Manufacturer Part Number
SR503-5
Type
3 with Priority Zones
AC Primary
120V
Number of Zones
3 with Priority
Power Port Slots
0
Current Ratings @ Voltages
FLA: 20 A @ 120V AC

Technical Documents

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TACO Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The TACO SR503-5 is a zone-switching relay with 3 zones with priority, operating on a 120V AC primary supply. It supports a full-load amperage (FLA) of 20 A at 120V AC. This switching relay is designed for zone control in hydronic heating systems.

Frequently Asked Questions

What is the TACO SR503-5 zone switching relay used for?

The TACO SR503-5 is used for zone control in hydronic heating systems. It switches circulator pumps or valves based on thermostat calls, with 3 zones including a priority zone to ensure the primary zone gets heat first.

What are the specifications of the TACO SR503-5?

The TACO SR503-5 is a 3-zone switching relay with priority, operating on 120V AC primary supply. It has a full-load amperage (FLA) of 20 A at 120V AC. The manufacturer part number is SR503-5.

Where to buy the TACO SR503-5 worldwide?

You can source the TACO SR503-5 through 3G Electric, a global industrial equipment distributor. We handle full logistics, customs clearance, and delivery to worldwide destinations. Contact us for availability and lead time.

How to install the TACO SR503-5 zone switching relay?

Install the TACO SR503-5 by mounting it on a wall or panel, connecting the 120V AC primary supply, and wiring each zone's thermostat and circulator. Follow the wiring diagram provided by TACO. Ensure power is off before installation and consult a licensed electrician.

Used in

Common applications for TACO
Hydronic heating systems — TACO 007 series circulator pumps for residential boiler water circulation.
Commercial HVAC — TACO 2400-60-3P inline pump for chilled water loops in large buildings.
Industrial process cooling — TACO 1630EAE10132096 pump for high-flow (110 gpm) cooling applications.
Zone control in radiant floor heating — TACO V075T2G2ZA024Q4A2 zone valve for regulating flow to individual zones.
Pump replacement and maintenance — TACO 007-045RP cartridge assembly for servicing existing 007 series pumps.
Piping connections in hydronic systems — TACO 110-251F-1 flange for joining pumps to pipework.

TACO Products

3G Electric supplies TACO zone-switching relays. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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