Inverters

Types

• Sine wave inverter — clean output safe for computers, fans, refrigerators and electronics. The standard choice today.
• Square or quasi-square wave inverter — cheaper but suited only to simple loads and can cause noise or heating.
• Solar PCU or hybrid inverter — charges batteries from solar panels as well as the grid, to cut grid use.
• Grid-tie inverter — feeds solar power directly into the building, usually without batteries.
• Inverter-UPS with high capacity — for larger shops, offices and clinics running many computers.

What to check before buying

• Capacity in VA or kVA, based on your connected load and the inverter power factor.
• System voltage (12 V, 24 V, 48 V), which decides how many batteries are connected.
• Waveform quality, overload protection, and the transfer time to battery.
• Battery type supported (tubular, SMF or lithium) and charging current.
• Whether it supports solar input, and the MPPT or PWM charge controller type.
• Warranty, on-site service, installation, AMC and GST invoice. Check that the battery warranty is clear.

Common brands include Luminous, Microtek, Exide, Su-Kam and Livguard.

Who buys them

Shops, small offices, clinics, schools, housing societies, coaching centres, workshops and households.

Frequently asked questions

What size inverter do I need for a small office?

Add the wattage of lights, fans, computers and printers, then choose a rating about 25 to 30 percent higher. Avoid including heavy loads like air conditioners.

Can an inverter run an air conditioner?

Only a large, specially sized system can. Most inverters are meant for lights, fans and electronics.

How long will the backup last?

That depends on battery capacity and load. A bigger battery bank gives longer backup but needs more space and cost.