A pure sine wave UPS produces the same smooth AC waveform as the grid. That is why it can safely run inverter ACs, fridges, computers and medical equipment that a cheaper UPS damages. In Pakistan our pure sine wave UPS units start at ₨93,000 (1,500VA). This guide explains the difference in plain terms and shows which appliances need a pure sine wave UPS.
Pure sine wave vs modified sine wave
| Modified / square wave UPS | Pure sine wave UPS | |
|---|---|---|
| Output shape | Stepped blocks | Smooth curve, like WAPDA supply |
| Fans and motors | Hum, run hotter, slower | Run quietly at normal speed |
| Inverter AC and fridge | May trip or misbehave | Run normally |
| Computers and LED TVs | Power supplies run hotter | No extra stress |
| Medical equipment | Not recommended | Recommended |
| Price | Lower | Higher |
Who should buy pure sine wave
- Clinics and labs: patient monitors, ECG machines, analyzers and ultrasound need clean power. A distorted waveform can cause false readings or damage the power supply.
- Homes with inverter appliances: inverter ACs, inverter fridges and washing machines.
- Offices: computers, servers and network equipment that should not restart during load-shedding.
- Anyone with ceiling fans on UPS: fans stay quiet and their capacitors and windings last longer.
Our pure sine wave range
We supply 1,500VA, 2,000VA, 2,500VA, 3,000VA and 4,000VA models, from ₨93,000 to ₨173,000. To work out the size and the batteries you need, use the two-step method in our UPS price guide.
How to tell if a UPS is really pure sine wave
- The rating plate or manual should say "pure sine wave", not just "sine wave" or "PSW technology".
- Ceiling fans on UPS power should sound the same as on mains power.
- A technician can check the waveform with an oscilloscope. Ask the supplier for a demonstration.
Installation tips
- Keep the UPS and batteries in a ventilated place, away from the kitchen and away from direct sunlight.
- Use battery cables of the correct thickness, and tighten the terminals properly.
- Top up water in flooded batteries every month or two.
- Put a stabilizer before the UPS in areas where the voltage swings a lot.
We deliver and install across Pakistan. Message +92 321 4444595 with your load list for a recommendation. See all sine wave UPS.