Spirax Sarco BT1050 is a sophisticated boiler blowdown timer designed for the precise control of bottom blowdown valves. By automating the removal of precipitated solids from the boiler bottom, the BT1050 prevents sediment build-up that can lead to significant boiler damage. The unit features three independent timers, allowing for complex scheduling such as distinct weekday and weekend blowdown cycles. It is suitable for installation on DIN rails, chassis plates, or via panel cutouts, providing versatility for various industrial control environments.

Key Features

• Independent Timers: Three separate timer sequences with four user variables: Duration, Start Time, Stop Time, and Repeat Interval.
• Multi-Boiler Management: Up to nine BT1050 units can be linked to prioritize blowdown cycles, preventing simultaneous discharge and overloading of blowdown vessels.
• Advanced Communication: Integrated RS485 Modbus RTU support for network integration and an Infrared (IR) link for local master/slave communication between adjacent units.
• Robust Safety: Built-in alarm relays for valve failure (lift/close failure), unauthorized tampering protection via pass codes, and TUV/UL certifications.

Technical Data

Feature	Specification
Supply Voltage	110 Vac to 240 Vac (50/60 Hz)
Power Consumption	230V/30 mA or 115V/60 mA
Relay Outputs	2 x Single Pole Changeover (SPCO), 3A @ 250 Vac
Ambient Limits	0°C to 55°C; 10% to 90% RH (non-condensing)
Battery Type	Lithium Thionyl Chloride AA (3.6V, 2.4 Ah)
Enclosure Material	ABS polycarbonate plastic (Light grey / Pantone 294 blue)

Front Panel and Operation

The front panel features a clear LCD graphics display divided into four sections showing the current time, timer information, information/date line, and recovery time. The five-button keypad allows for intuitive menu navigation and parameter adjustment.

Installation and Wiring

The BT1050 requires vertical orientation and must be protected from environmental pollutants. For panel mounting, a cutout of approximately 92x92mm is required. Electrical installation should be performed by qualified personnel, following standard EMC and LVD guidelines.

Functional Earth

The earth terminal is a functional earth used as a sink for electrical interference to conform to EMC directives. As the product features double insulation, a protective earth is not required for electrical safety.

Communication Networking

• RS485: Supports 2-wire half-duplex or 4-wire full-duplex Modbus RTU communication.
• Infrared Bus: Facilitates parameter passing between up to seven slave products and a master product, reducing wiring complexity in multi-unit panels.

Maintenance and Fault Finding

The unit is designed for minimal maintenance. A test menu allows for diagnostic checks of the display, inputs (internal temperature, link status, switch status), and outputs (manual valve and alarm relay operation). A field-replaceable lithium battery maintains the clock calendar during power outages.