At SJ Dynamics, we specialize in delivering UPS systems that protect your equipment and keep your operations running during power failures or fluctuations. A UPS (Uninterruptible Power Supply) provides battery backup power to critical loads such as computers, servers, routers, and medical equipment. When mains electricity fails, the UPS instantly switches to battery power, ensuring continuity and preventing costly downtime.
Types of UPS Systems
Online UPS With online technology, your load is continuously supplied with clean, sinusoidal power. Incoming AC power is converted to DC, stored in the batteries, and then inverted back to AC. This design ensures there is no break in power during an outage ideal for sensitive equipment that requires pure sine wave output.
Offline / Line‑Interactive UPS These designs are more affordable and suitable for smaller loads such as PCs, monitors, TVs, routers, and cameras. They supply AC power directly from the mains and switch to battery backup only when needed. While there is a very short break in power (typically 3ms), most small devices are designed to handle this without issue.
Battery Options
Standard Internal Batteries Entry‑level UPS units include internal batteries designed to provide 10–15 minutes of backup at average load. These are ideal for short interruptions until standby power kicks in.
Long‑Run UPS with External Batteries For extended backup, long‑run UPS systems are built with larger chargers and components to handle external battery banks. Light loads such as routers, switches, and cameras can run for 24 hours or more. For heavier loads, your UPS supplier will size the system based on your VA/W requirements and provide pricing for different runtime options.
When to Consider Other Solutions
While long‑run UPS systems are effective, they are only economically viable up to a point (e.g., 8 hours on a 3kVA load). Beyond that, generators or solar solutions may be more cost‑effective for extended backup.
Why Choose SJ Dynamics?
- Expertise in UPS systems, solar solutions, generators, and batteries
- Level 2 BBBEE company registered with the National Treasury CSD
- Trusted by corporates, parastatals, and government departments across South Africa
When should I choose a UPS instead of solar or a generator?
Choose a UPS when you need instant, clean power and surge protection for a limited time (computers, network gear, cameras, medical devices, point-of-sale systems). For multi-hour or whole-house backup, hybrid solar with batteries or a generator is more practical. Many clients use a UPS for critical loads and pair it with solar or a generator so they are covered for both short outages/surges and longer power cuts, whether caused by local faults or a possible return of load shedding.
What is the difference between online and offline UPS?
An online UPS continuously converts power and supplies pure sine-wave electricity with zero transfer time — ideal for servers, medical equipment and sensitive electronics that cannot tolerate even a brief interruption or dirty power. Offline (or line-interactive) UPS units are more affordable and switch to battery in a few milliseconds; they work well for PCs, monitors, TVs, routers and till points. Both types protect against surges. Most home and small-office users are fine with offline; critical infrastructure needs online.
How long will a UPS keep my equipment running during a power outage or surge?
A standard UPS with internal batteries usually gives 10–15 minutes of clean power — enough to ride through short faults or shut computers down safely. Long-run UPS systems with external battery banks can keep light loads (routers, switches, cameras, small servers) running for many hours. UPS systems also filter voltage surges and spikes that often occur when power is restored after an outage. Beyond about 8 hours on a 3kVA load it is usually more economical to move to solar + batteries or a generator.
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