Technical data, tools and notes for refrigeration and electronics technicians.

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The Cooling Workhorse: Deep Dive into the Danfoss NL7.3FT Compressor mbsmpro
31, Jan 2026
The Cooling Workhorse: Deep Dive into the Danfoss NL7.3FT Compressor

The Danfoss NL7.3FT is a cornerstone of domestic and light commercial refrigeration. Engineered for Low Back Pressure (LBP) applications using R134a refrigerant, this 1/4 HP unit offers reliability and high efficiency. In this guide, we break down the technical displacement, cooling capacity, and provide a comprehensive list of compatible replacements…

Excellent Compressor GS91AZ 1/3 HP R134a 9.1cc mbsmpro
18, Jan 2026
Excellent Compressor GS91AZ 1/3 HP R134a 9.1cc

The Excellent Compressor GS91AZ has established itself as a robust solution for engineers and technicians looking for a durable replacement in various cooling appliances. Designed specifically for Low Back Pressure (LBP) applications, this reciprocating unit balances power and energy savings, making it a staple in the high-performance refrigeration and cooling…

R134a vs. R600a Compressor Conversion mbsmpro
2, Jan 2026
R134a vs. R600a Compressor Conversion

Switching from R134a to R600a requires more than just changing the gas. This guide explains the critical "Displacement Rule"—why R600a compressors need nearly double the cylinder volume of R134a units to produce the same cooling. We cover charge calculation (45% rule), oil compatibility, and safety protocols for the modern artisan.

Mbmpro 2025 12 26 190305
26, Dec 2025
Compressor database chart Relay Olp 

A refrigerator compressor does not run alone; it depends on a start relay and an overload protector (OLP) to start safely and avoid burning out. The wiring diagram of compressor, relay, and OLP shows how power flows from the thermostat, through protection devices, to the motor windings, keeping domestic fridges…