Simplex synchronized clock systems are found in thousands of schools, hospitals, government buildings, and institutional facilities across North America. These systems provide precisely coordinated timekeeping throughout large facilities — ensuring every clock in every room, hallway, and common area displays exactly the same time. When a clock fails or needs replacement, matching the correct replacement model is critical to maintaining system synchronization. This guide covers the Simplex 6310-9231 12-inch round clock and the broader Simplex time system architecture.
How Simplex Synchronized Clock Systems Work
Simplex time systems operate on a master/secondary architecture. A master clock controller — typically a Simplex 6400 or 6600 series master clock — acts as the central timekeeping authority. The master clock receives time signals (from GPS, network NTP, or internal crystal oscillator) and distributes synchronized time pulses to all secondary clocks throughout the facility via dedicated wiring.
Secondary clocks receive these pulses and advance their hands (or update their digital displays) in synchronization. The result is a facility-wide synchronized time display with all clocks matching to within seconds of each other. In schools, this is essential for coordinating class periods. In hospitals, accurate synchronized time affects medication records, patient documentation, and code event timing.
Simplex uses several wiring protocols for distributing time signals, including:
- 58-minute (impulse) systems: Older analog systems where the master clock sends a pulse every minute
- Digital/serial systems: Newer systems using data communication for precise synchronization
- POE (Power over Ethernet) systems: Modern networked clocks receiving time via NTP over the facility network
The Simplex 6310-9231: Specifications and Features
The Simplex 6310-9231 12-inch round replacement synchronized clock is one of the most widely used secondary clock models in Simplex installations. Key specifications include:
- Face diameter: 12 inches
- Style: Round analog with hour and minute hands
- Housing: White thermoplastic, surface mount
- Compatibility: Designed for Simplex 58-minute impulse time systems and compatible digital systems
- Power: Receives power and time signals from the Simplex time system wiring
The 6310-9231 is a direct replacement for aging Simplex round clocks of the same form factor. The mounting footprint, wiring connections, and synchronization protocol are designed for drop-in replacement without panel reprogramming in most installations.
Identifying Your Simplex Clock System Before Ordering
Before ordering replacement clocks, it’s essential to identify which Simplex time system is installed. The key information you need:
- Master clock model number: Found on the master clock panel, typically in a dedicated clock room or mechanical room
- Clock protocol: 58-minute impulse, serial digital, or network/POE
- Clock mounting: Surface mount, flush mount, or wall-guard mount
- Clock size: 12-inch, 15-inch, or other diameter
Mixing clock protocols is a common mistake that results in clocks that won’t synchronize. A digital-protocol replacement won’t work on a 58-minute impulse system, even if the physical mounting matches perfectly.
Replacement Process: Step-by-Step
Replacing a Simplex secondary clock is typically straightforward:
- Disconnect power at the master clock or local disconnect — this prevents the system from sending pulses during replacement
- Remove the failed clock — unscrew the mounting screws and disconnect the two-wire time system leads
- Document the existing wiring connections — photograph before disconnecting
- Connect the replacement clock — polarity matters on some systems; verify with the master clock documentation
- Mount and secure the replacement clock
- Restore power and verify synchronization — most Simplex secondary clocks will self-correct to the master clock within one full cycle after power restoration
Maintaining Simplex Time Systems in Schools and Hospitals
In educational facilities, Simplex clock systems are often tied to bell scheduling systems — the same master clock that synchronizes wall clocks also triggers period bells, PA system announcements, and in some installations, is integrated with the fire alarm panel for evacuation timing. When replacing clocks in school applications, verify the replacement is compatible with any bell relay functionality if the failed clock incorporated that feature.
In hospital applications, synchronized clocks may be subject to specific accreditation requirements (The Joint Commission standards reference accurate time displays in patient care areas). Replacement should be completed promptly and documented.
Finding Simplex Clock Replacement Parts
Simplex time system parts — including secondary clocks, master clock components, and accessories — are available through Life Safety Consultants. Browse the complete Simplex parts catalog for current availability. When ordering, note your master clock model number and the exact clock model being replaced to ensure compatibility. For large-scale clock replacements in school or hospital facilities, contact Life Safety Consultants directly for volume pricing and compatibility consultation.
