Circuit breakers and fuses
Disconnect circuits under overload or short circuit before conductors overheat or are damaged.
Service 05 · Safety & Security
Electrical Safety and Integrated Security Systems
Safety and security in buildings rely on electricity in two ways: the electrical installation must protect people and property from its own hazards, and security equipment needs a dependable electrical infrastructure to function when it matters.
Foundation
Building safety and electrical infrastructure
Electrical faults are a recognised cause of fires and injuries. The installation itself is the first line of defence: correctly rated protective devices, effective earthing, sound insulation and appropriate enclosures prevent most hazards from developing. Security and life-safety systems — access control, surveillance, intruder alarms and emergency lighting — then build on that foundation.
Treating these as one subject helps avoid common gaps, such as a security system supplied from a general socket circuit that can be switched off accidentally, or surveillance cabling run alongside power cables without regard for interference.
Protection devices
Electrical protection devices
Each device addresses a specific hazard. Together they form a layered protection strategy that the applicable regulations define in detail.
Residual current devices
Detect current leaking to earth — through a person or damaged insulation — and disconnect rapidly to reduce the risk of shock and fire.
Surge protective devices
Limit transient overvoltages from lightning or switching events that can damage sensitive electronics, including security and IT equipment.
Earthing and bonding
Provide a low-impedance path for fault current and keep exposed metalwork at a safe potential so protective devices can work as intended.
Security infrastructure
The electrical layers behind security systems
Security equipment is only as dependable as the power and cabling that serve it.
Access control technology
Card readers, keypads and biometric units connect to door controllers that release electric locks or magnetic holds. Lock type determines fail-safe or fail-secure behaviour on loss of power, which must be coordinated with fire escape requirements. Controllers need protected supplies and, typically, battery backup.
Security system wiring infrastructure
Data, signal and low-voltage cabling should be routed in dedicated containment and segregated from power circuits to limit interference and accidental damage. Clear labelling of cables and patch points simplifies future changes and fault finding.
Surveillance system connectivity
Network cameras are commonly powered and connected over the same cable using Power over Ethernet. Switch capacity, cable lengths, outdoor enclosures and surge protection at external cameras all need attention. Recorders and network equipment should be housed in secure, ventilated locations.
System integration considerations
Access control, surveillance, intruder alarms and fire detection increasingly share networks and interfaces. Integration — such as releasing doors on fire alarm or linking cameras to access events — must be planned so that one system's failure does not compromise another's safety function.
Continuity
Power reliability for security equipment
Security systems are often most needed during abnormal conditions, including power disturbances. Dedicated, clearly labelled circuits reduce the chance of accidental disconnection. Uninterruptible power supplies and battery-backed power units keep controllers, recorders and cameras running through short outages.
Backup capacity should be sized for the required autonomy, and batteries have a finite life, so they must be tested and replaced on schedule. Surge protection at the distribution board and at exposed external equipment helps protect sensitive electronics.
Supply checklistREF S-05
- Circuit
- Dedicated and labelled, not shared with general loads
- Backup
- UPS or battery units sized for required autonomy
- Surge
- Protection at board and exposed outdoor equipment
- PoE budget
- Switch power capacity matched to connected devices
- Locks
- Fail-safe / fail-secure agreed with escape requirements
Autonomy and lock behaviour requirements vary by building type and local regulation.
M
Inspection and maintenance
Protective devices, backup batteries, door hardware and cameras all degrade over time. Periodic testing of RCDs, checks of surge protector status, battery load tests and verification of door release functions keep systems trustworthy. The general approach is described on the Electrical Maintenance page.
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Risk reduction and electrical safety
Risk is reduced by understanding where hazards arise — overloaded circuits, deteriorated insulation, inadequate earthing, unprotected outdoor equipment — and addressing them systematically. Documentation of what is installed, and how it is supplied, allows faults to be resolved quickly and safely.
Reviewing electrical safety or security infrastructure?
Let us know which systems are involved, the type of building and whether you are planning new equipment or assessing an existing setup.