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The Sierra Radio Systems SIR-471 is a 20A DC power relay partial kit for the Sierra Station Controller range.
It is designed to switch DC power on and off to a connected load, making it useful for remotely controlling station accessories, DC-powered equipment, relay-driven systems, and other power circuits from a Sierra Station Controller installation.
The SIR-471 is normally connected to the open-collector relay control outputs on the SIR-321 General Purpose GPIO Module, allowing DC loads to be switched from the Station Controller dashboard or wider automation system.
This is a partial kit. The main relay board is supplied assembled, but the user must solder and install the Powerpole connectors, then assemble the mounting plate and DIN rail clips.
Key Features
- 20A DC power relay partial kit
- Designed for Sierra Station Controller systems
- Used to turn DC power on or off to a connected load
- Relay rated for 30A
- PCB traces conservatively rated to 20A
- 12V DC SPST power relay design
- Normally controlled from the open-collector outputs on the SIR-321 GPIO module
- Pull-to-ground relay control input
- External connections for 12V power input
- Voltage measurement points for voltage in and voltage out
- LED indicator shows relay state
- Includes mounting plate, DIN rail clips, and hardware
- Powerpole connector installation required
- Suitable for remote station, repeater site, and shack automation projects
Typical Uses
- Remotely switching DC-powered station accessories
- Turning equipment on or off from a Station Controller dashboard
- Remote HF station power control
- Repeater site power switching
- Shack automation projects
- Switching auxiliary DC loads
- DIN rail mounted station control panels
- Adding higher-current DC switching to an SIR-321 GPIO module installation
Station Controller System Role
The SIR-471 adds higher-current DC power switching to a Sierra Station Controller installation.
It is typically controlled by the SIR-321 General Purpose GPIO Module, using one of the GPIO module’s open-collector relay control outputs. This allows a relatively small control output to operate a larger DC power relay for switching equipment or accessories.
The SIR-471 does not communicate directly on the Sierra DCN network. Instead, it is used as a controlled accessory connected to a compatible GPIO or relay control output.
Assembly Note
This product is supplied as a partial kit.
The relay board is supplied with the power relay, LED indicator, and 8-pin connector already installed. The user must solder in the Powerpole connectors and assemble the mounting plate and DIN rail clips before installation.
Connections and Functions
| Function | Details |
|---|---|
| Relay type | 12V DC SPST power relay |
| Relay rating | 30A |
| Board trace rating | 20A |
| Control input | Pull-to-ground relay control |
| DC power connections | 12V power input and switched output |
| Monitoring points | Voltage in and voltage out measurement points |
| Status indication | LED relay state indicator |
| Typical controller | SIR-321 GPIO module open-collector output |
| Mounting | Mounting plate and DIN rail clips supplied |
Specifications
| Specification | Details |
| Brand | Sierra Radio Systems |
| Model | SIR-471 |
| Product type | 20A DC power relay partial kit |
| Relay type | SPST DC power relay |
| Relay voltage | 12V DC |
| Relay rating | 30A |
| Conservative board rating | 20A |
| Control method | Pull-to-ground relay control |
| Typical control module | SIR-321 General Purpose GPIO Module |
| Connectors | Powerpole connectors, user installed |
| Status indicator | Relay state LED |
| Assembly required | Yes, soldering and assembly required |
Important Note
This listing is for the SIR-471 20A DC Power Relay Partial Kit only.
SIR-321 GPIO module, SIR-310 host adapter, installation kit, DCN hub, power supply, DC load, wiring, fuses, station equipment, and other accessories are not included unless stated otherwise.
This is a partial kit and requires soldering and assembly before use. The user must install the Powerpole connectors, mounting plate, and DIN rail clips.
Please ensure that the connected load, wiring, fuse protection, power source, and installation are suitable for the voltage and current being switched.
Shipping & Delivery
We offer UK and international delivery services, including next working day and selected weekend options for eligible orders. Available services, prices and estimated delivery times are displayed at checkout.
Delivery Information
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Exceptions
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Additional return conditions may apply to equipment modified at the customer's request, including wideband transmit or receive modifications.
ML&S may charge a reasonable fee to reverse physical modifications and restore the equipment to its original factory specification. Any such charge will be agreed in advance and deducted from your refund.
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Faulty or Incorrectly Supplied Goods
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Refunds will be issued to the original payment method. Any prepaid return postage charges or lawful deductions for diminished value will be itemised.
Warranty Terms & Conditions
New Equipment Warranty
Minimum 2-Year Warranty
All new products supplied by ML&S carry a minimum two-year warranty against manufacturing defects, excluding batteries, which are covered by separate warranty terms.
Some manufacturers provide extended warranties, such as the three-year warranty available on eligible Yaesu equipment. Any additional coverage is subject to the manufacturer's terms and conditions.
Our workshop may assess and repair faulty equipment on site or refer it to the manufacturer or an authorised service centre where necessary.
Warranty exclusions may include batteries, normal wear and tear, accidental damage, misuse and unauthorised modifications, as specified in the applicable warranty terms.
All warranties are provided in addition to your statutory consumer rights against ML&S, which are not limited by the warranty period.
International Returns & Warranty
Unless otherwise stated, ML&S warranty servicing is carried out in the UK. International customers must contact us before returning goods to confirm shipping and customs requirements.
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