SD System Lightning Protection for Irrigation Controllers

Protect your irrigation investment with Signal's lightning protection system, designed specifically for SDS Series Two-Wire Irrigation Controllers. Electrical surges caused by nearby lightning strikes or power anomalies can damage controller electronics and field devices — which is why Signal offers a comprehensive surge protection solution tailored to two-wire systems.

This product includes three module types that work together to protect both the controller and field wiring:

• SD-SP (Surge Protector):
  Standard with every controller, this module is installed at the controller and must be connected to a properly earthed ground stake. It safeguards the main controller and power input from electrical surges.
• SD-SA (Surge Arrestor):
  Optional but highly recommended for extended two-wire networks. Install every 300–400 metres, or approximately every 16 valves, along the two-wire cable. Provides in-field surge suppression to protect decoders, DataCoils™, and other connected devices.
• SD-GR (Grounding Rod Kit):
  A recommended grounding solution for SD-SP and SD-SA installations. Designed to meet the ≤10 Ohm earth resistance requirement for optimal protection.

FEATURES

• Comprehensive Surge Protection – Protects both controller and field components from lightning and power surges
• Required for Warranty Compliance – SD-SP must be installed for system warranty coverage
• SD-SP Included with Controllers – Pre-supplied with all SDS-50 and SDS-100 controllers
• Modular Expansion – Add SD-SA units in-field for extended protection across large sites
• Installation Guidance:
  • Install SD-SP at the controller, as close as possible to the earth stake
  • Use flat braided cable for grounding
  • Install SD-SA units every 300–400 metres or 16 valves
  • Ensure all units are grounded with resistance of 10 Ohms or less
• Use Approved Connectors Only – Waterproof two-wire connectors must be used with SD-SA units

SPECIFICATIONS

• Product Names:
  • SD-SP: Surge Protector for controller grounding
  • SD-SA: Field Surge Arrestor for two-wire cable protection
  • SD-GR: Grounding Rod Kit (minimum 2m length recommended)
• Application: Lightning and surge protection for SDS two-wire systems
• Installation Points:
  • SD-SP: At controller
  • SD-SA: Every 300–400m or 16 valves along two-wire path
• Ground Resistance Requirement: ≤10 Ohms
• Compatible Controllers: SDS-50 and SDS-100
• Connection Method: Approved waterproof two-wire connectors; placed inside valve boxes or access pits