1. What is the Refrigerator PSU Calculation?

The refrigerator PSU calculation determines the appropriate power supply unit wattage needed to safely power a refrigerator, accounting for startup surges and providing a safety margin.

2. How Does the Calculator Work?

The calculator uses the refrigerator PSU formula:

Where:

• \( P_{total} \) — Required PSU wattage (W)
• \( P_{refrigerator} \) — Refrigerator's rated wattage (W)
• \( 1.2 \text{ to } 1.3 \) — Safety factor (20-30% margin)

Explanation: The safety factor accounts for startup surges (compressor kick-in) and provides headroom for reliable operation.

3. Importance of Proper PSU Sizing

Details: Undersized PSUs can cause voltage drops, compressor failures, or frequent tripping. Oversized PSUs waste energy and money. The 20-30% margin balances safety and efficiency.

4. Using the Calculator

Tips: Enter the refrigerator's rated wattage (found on nameplate or manual) and select safety factor (1.2 for typical use, 1.3 for older units or unstable power).

5. Frequently Asked Questions (FAQ)

Q1: Why is a safety factor needed?
A: Refrigerators have high startup currents (3-5× running current) when the compressor kicks in. The safety margin prevents overload.

Q2: What if I don't know my refrigerator's wattage?
A: Check the nameplate or manual. As estimate: small fridges ≈100W, medium ≈150W, large ≈200W, commercial ≈300W+.

Q3: Can I use this for other appliances?
A: This is specific to refrigerators. Other appliances may need different safety factors (e.g., motors often need 1.5×).

Q4: Should I consider inverter efficiency?
A: If using an inverter, add 10-15% to account for conversion losses (e.g., use 1.3-1.45× total factor).

Q5: What about battery backup systems?
A: For battery systems, also consider runtime requirements and depth of discharge when sizing batteries.