The codes L55AV and QD59H refer to specific types of refrigerator compressors utilized in household and small-scale commercial cooling systems. Below is a detailed breakdown of the manufacturing materials and technical specifications for each model:
1. L55AV Compressor
The L55AV is a compressor manufactured by Cubigel (currently part of the Huayi Group). It is specifically designed to operate with the legacy R12 refrigerant (or its retrofitted substitutes) and features an approximate capacity of 1/6 HP.
Primary Manufacturing Materials:
Outer Shell (Housing): Constructed from deep-drawn carbon steel, which is coated with a specialized layer to resist rust and harsh environmental conditions.
Electric Motor: Comprised of a core made from silicon steel laminations and windings of high-purity copper. (While some modern “economy” versions may use aluminum, copper remains the standard for original high-performance models).
Pumping Mechanism (Cylinder and Piston): Typically manufactured from corrosion-resistant Cast Iron to ensure durability against friction and extreme heat.
Crankshaft: Made of alloy steel or heat-treated cast iron for structural integrity.
Valves: Fabricated from high-flexibility Spring Steel to withstand thousands of rapid opening and closing cycles.
2. QD59H Compressor
The QD59H is a widely distributed compressor manufactured by Huayi and other global producers. It is designed primarily for R134a refrigerant and maintains a capacity of approximately 1/6 HP.
Manufacturing Materials and Technical Features:
Internal Components: Largely similar to the L55AV, utilizing cast iron for the piston/cylinder assembly and heavy-duty steel for the external shell.
Motor Windings: Predominantly copper to guarantee high energy transmission efficiency and optimized power consumption.
Suspension System: Features internal steel springs designed to absorb operational vibrations and minimize noise levels.
Specialized Materials: Some technical reports for modern QD59H iterations indicate the use of ceramic balls in specific bearing types to reduce friction and extend service life, alongside gaskets made of advanced polymers.
Material Comparison Summary Table
Component
Common Materials (L55AV & QD59H)
Outer Shell
Coated Carbon Steel
Motor Windings
Pure Copper (Rarely Aluminum)
Piston & Cylinder
Cast Iron
Valves
Stainless Steel / Spring Steel
Refrigerant Gas
R12 (L55AV) / R134a (QD59H)
Insulation
Mineral/Synthetic Oil and Paper/Plastic motor insulators
Focus Keyphrase: L55AV and QD59H Refrigerator Compressor Technical Specifications and Performance Comparison
Meta Description: Expert technical guide for L55AV and QD59H compressors. Discover cooling capacity, displacement, 1/6 HP performance, and R12 to R134a conversion insights for HVAC engineers.
Excerpt: The L55AV and QD59H are cornerstone compressors in the domestic refrigeration industry, both rated at 1/6 HP. While the L55AV traditionally operates with R12, the QD59H is the modern R134a standard. This article provides deep technical data, electrical wiring diagrams, and professional comparison tables for field technicians and refrigeration engineers seeking reliable data.
In the demanding field of refrigeration maintenance and engineering, the reliability of a compressor defines the lifespan of the appliance. Today, we analyze two workhorses of the industry: the L55AV and the QD59H. As an engineer who has spent years in the workshop and on-site, I can testify that understanding the subtle metallurgical and chemical differences between these two models is the difference between a successful repair and a repetitive failure.
The Technical Evolution: L55AV and QD59H
The L55AV (often associated with brands like Cubigel, Zem, or Huayi) is a classic reciprocating compressor. Historically, it was the go-to choice for units using R12 refrigerant. On the other hand, the QD59H represents the modern shift, optimized for R134a. Both are classified as LBP (Low Back Pressure) units, typically found in household refrigerators and medium-sized chest freezers.
Technical Specifications Table
Characteristic
L55AV Model
QD59H Model
Horsepower (HP)
1/6 HP
1/6 HP
Displacement
5.44 cm³
5.9 cm³
Refrigerant Type
R12 / R406a
R134a
Cooling Capacity
130W – 145W
160W – 165W
Voltage Range
220-240V / 50Hz
220-240V / 50Hz
Motor Type
RSIR (Relay Start)
RSIR / RSCR
Evaporating Temp
-35°C to -10°C
-35°C to -15°C
Oil Type
Mineral
POE / Synthetic
Engineering Comparison: Displacement vs. Efficiency
When comparing these two, a critical factor for the field worker is the Displacement. The QD59H offers a slightly larger displacement at 5.9 cm³ compared to the 5.44 cm³ of the L55AV. This allows the QD59H to achieve a higher cooling capacity (approx. 160W) while maintaining a standard 1/6 HP footprint.
Value Comparison with Similar Models
Model
HP Rating
Gas Type
Capacity (W)
Efficiency (COP)
L55AV
1/6
R12
145
1.15
QD59H
1/6
R134a
165
1.22
GL60AA
1/6
R134a
155
1.20
FN66Q
1/6
R12
140
1.10
Electrical Schema and Wiring Configuration
For the electric setup, these models generally utilize the RSIR (Resistance Start Induction Run) system. Below is the typical connection logic:
Common (C): Top pin of the compressor triangle.
Start (S): Connected to the PTC starter or electromagnetic relay.
Run (R): Main power line connected directly to the winding.
Note for Technicians: Always verify the resistance between C-S and C-R. The Start winding (C-S) will always show a higher resistance than the Run winding (C-R). If you are replacing an L55AV with a modern QD59H, ensure your Overload Protector (OLP) is matched to the 1.1A to 1.3A running current of the new unit.
Field Worker’s Advice: Professional Installation Tips
System Flushing: If you are replacing an old L55AV (R12) with a QD59H (R134a), you must flush the evaporator and condenser with R141b. R12 systems use mineral oil, which is incompatible with the POE oil found in R134a compressors. Mixing them creates an acidic sludge that will choke your capillary tube.
Vacuum Procedure: Never settle for a “short vacuum.” Because the QD59H uses synthetic oil, it is highly hygroscopic (absorbs moisture). A minimum vacuum of 500 microns is recommended to ensure system longevity.
Filter Drier: Always install a new XH-9 molecular sieve filter drier when switching to R134a.
Benefits of the QD59H over Older Models
Lower Noise Profile: The internal suspension of the QD59H is designed with high-tension springs that reduce “chatter” during start-stop cycles.
Thermal Stability: The windings in the QD59H are often insulated with higher-grade polymers that resist burnout during voltage fluctuations common in 220V grids.
Technical Catalogs and Resources
For engineers requiring the full manufacturer curves and torque data, you can refer to the following official documentation (Ensure you are using a secure browser):
Final Notice: When working on these projects, always verify the LRA (Locked Rotor Amps) on the nameplate. For a 1/6 HP unit like the QD59H, it should typically range between 6A and 8A. If your reading is higher, check for mechanical binding or a faulty start capacitor. Be smart, be an engineer, and prioritize system cleanliness above all else.
Mitsubishi Ashiki MUY-JX22VF electrical technical data interpretation
Category: Air Conditioner
written by www.mbsmpro.com | January 18, 2026
HOW TO READ AC NAMEPLATE SPECIFICATIONS: COMPLETE TECHNICAL GUIDE
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How to read AC nameplate specifications voltage amperage refrigerant type cooling capacity model number tonnage Mitsubishi Ashiki MUY-JX22VF electrical technical data interpretation
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How to Read AC Nameplate Specifications: Complete Decoding Guide for Technicians & Owners
Meta Description (155 characters):
Learn how to read AC nameplate specifications with complete guide. Decode model numbers, voltage, amperage, refrigerant type, tonnage, cooling capacity, technical data.
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Excerpt (First 55 Words):
Master the skill of reading AC nameplate specifications with this comprehensive technical guide. Learn to decode model numbers, interpret voltage and amperage ratings, identify refrigerant types, calculate cooling capacity, determine tonnage, and understand all electrical information displayed on your air conditioning unit nameplate.
COMPREHENSIVE ARTICLE CONTENT:
Understanding the AC Nameplate: Your Unit’s Complete Technical Profile
Introduction
The air conditioner nameplate is far more than a decorative label—it’s a comprehensive technical document containing every critical specification your unit needs to operate safely, efficiently, and effectively. Whether you’re a licensed HVAC technician, building maintenance professional, or curious homeowner, understanding how to read and interpret the information on an AC nameplate is essential for troubleshooting, repairs, maintenance planning, and purchasing decisions.
The Mitsubishi Ashiki MUY-JX22VF nameplate demonstrates a complete example of how manufacturers present technical information. This guide breaks down every element of the AC nameplate, from basic identifiers to complex electrical specifications.
PART 1: NAMEPLATE LOCATION & PHYSICAL CHARACTERISTICS
Where to Find the AC Nameplate
Outdoor Unit Nameplate:
Location
Visual Characteristics
Access Level
Side panel
Usually right-facing side
Easy access, outdoor
Top access panel
Cover may require removal
Moderate access
Compressor side
Bolted directly to unit
Professional access
Condenser frame
Mounted on metal housing
Visual inspection
Indoor Unit Nameplate (if present):
Back panel behind unit
Inside service compartment
Sometimes absent (specs on outdoor unit only)
Physical Nameplate Materials
Material Type
Durability
Readability
Weather Resistance
Aluminum/Metal plate
Excellent
Excellent
Very high
Plastic label
Good
Good
Moderate
Adhesive sticker
Fair
Good initially
Can fade/peel
Engraved metal
Excellent
Excellent
Permanent
PART 2: DECODING THE MODEL NUMBER
Model Number Structure Explained
The model number is the primary identifier. Using Mitsubishi Ashiki MUY-JX22VF as reference:
Cooling Capacity (Tons) = Two-digit capacity number ÷ 12
Example Conversions:
Model Code Number
Divided by 12
Tonnage
BTU/Hour
Kilowatts
09
÷ 12
0.75
9,000
2.6 kW
12
÷ 12
1.0
12,000
3.5 kW
18
÷ 12
1.5
18,000
5.3 kW
22
÷ 12
1.83 (1.9)
22,800
6.6 kW
24
÷ 12
2.0
24,000
7.0 kW
30
÷ 12
2.5
30,000
8.8 kW
36
÷ 12
3.0
36,000
10.5 kW
42
÷ 12
3.5
42,000
12.3 kW
48
÷ 12
4.0
48,000
14.0 kW
60
÷ 12
5.0
60,000
17.6 kW
Series Code Meanings
Series Code
Technology Type
Compressor Style
Energy Efficiency
Cost
JX
DC Inverter (Mitsubishi)
Variable-speed
High (4.0+)
Premium
GE
Standard Inverter
Variable-speed
Moderate (3.5-3.9)
Moderate
JS
Basic Inverter
Fixed-stage
Low (3.0-3.4)
Low-Moderate
Non-letter
Non-inverter
Fixed-speed
Very Low
Lowest
PART 3: ELECTRICAL SPECIFICATIONS
The Voltage Section
Typical nameplate notation:
textVOLTAGE: 230 V
PHASE: 1 (Single Phase)
FREQUENCY: 50 Hz
What this means:
Specification
Value
Importance
Requirement
Voltage (V)
230V ± 10%
Power supply requirement
Must match exactly
Phase
Single phase (1Ph)
Electrical configuration
Determines circuit type
Frequency (Hz)
50 Hz
AC cycle rate
Region-specific (50 Hz = Asia/Europe)
Voltage Tolerance Range
The ±10% rule:
For a 230V rated unit:
Voltage Type
Actual Voltage
Safe Operation
Risk Level
Minimum safe
207V
Yes
Acceptable
Nominal
230V
Yes
Optimal
Maximum safe
253V
Yes
Acceptable
Below minimum
<207V
No
Compressor damage
Above maximum
>253V
No
Component burnout
Real-world implication: A 230V AC unit operates safely between 207-253V. Outside this range triggers protection mechanisms.
Frequency Specification (Hz)
Frequency
Regions
Compressor Speed
Incompatibility
50 Hz
Europe, Asia, Middle East, Africa
3,000 RPM (no load)
Cannot use in 60 Hz regions
60 Hz
North America, South America, Japan
3,600 RPM (no load)
Cannot use in 50 Hz regions
Critical warning: A 50 Hz unit will not work in a 60 Hz supply (and vice versa). Compressor will either fail to start or operate dangerously.
PART 4: AMPERAGE RATINGS EXPLAINED
Types of Amperage on the Nameplate
Three different amperage ratings appear on AC nameplates, each serving different purposes:
Rating Type
Abbreviation
Value (typical 1.9-ton)
Meaning
Used For
Rated Load Amps
RLA
9.0-9.2 A
Manufacturer’s design current
Breaker sizing
Locked Rotor Amps
LRA
28-35 A
Startup current (compressor locked)
Equipment protection
Minimum Circuit Ampacity
MCA
11.0 A
Minimum wire size required
Electrical installation
Understanding RLA (Rated Load Amps)
The most important amperage specification:
RLA Definition: The steady-state current draw when the compressor operates at rated cooling capacity under standard test conditions (outdoor 35°C/95°F, indoor 26.7°C/80°F).
For the Mitsubishi Ashiki MUY-JX22VF:
RLA = 9.0-9.2 Amperes
This is the “normal” running current
Interpretation:
Circuit breaker sized for RLA safety
Unit should draw approximately this current during operation
Higher current indicates problems (low refrigerant, dirty coils)
Lower current indicates reduced capacity
Understanding LRA (Locked Rotor Amps)
The startup specification:
LRA Definition: The maximum current drawn when the compressor motor starts and rotor is initially locked (not yet spinning).
For similar 1.9-ton units:
LRA = 28-35 Amperes (3-4x the RLA)
Why this matters:
The starting current is dramatically higher than running current because:
Motor starting requires breaking initial static friction
No back-EMF initially (back-EMF develops as motor spins)
Resistance is minimal at startup
Brief but intense current spike (typically <1 second)
Electrical design consequence: Circuit breakers and wire must handle brief LRA spikes without nuisance tripping.
Understanding MCA (Minimum Circuit Ampacity)
The electrical installation specification:
MCA Definition: The minimum current-carrying capacity of the supply wire and circuit breaker needed to safely supply the unit.
Typical MCA = 125% of RLA
For RLA of 9.0A:
MCA = 9.0 × 1.25 = 11.25A (rounded to 11.0A)
Installation requirement: An electrician must use:
Wire rated for at least 11 Amperes
Circuit breaker rated for at least 15 Amperes (standard minimum in residential)
Dedicated circuit (not shared with other devices)
Actual Current Draw During Operation
Real-world vs. rated current:
Operating Condition
Expected Current
Explanation
Startup (compressor kick-in)
20-35A (LRA range)
Locked rotor startup spike
Acceleration phase
12-18A
Motor speeding up
Full load operation
8-10A (RLA)
Steady-state cooling
Part-load operation
4-7A
Reduced speed (inverter)
Idle/standby
0.1-0.3A
Minimal draw, electronics only
Inverter advantage: DC inverter units (like MUY-JX22VF) can ramp up gradually, avoiding the harsh LRA spike that damages older equipment and causes electrical stress.
PART 5: REFRIGERANT SPECIFICATIONS
Refrigerant Type Identification
The nameplate clearly identifies the refrigerant chemical used in the unit:
Refrigerant
Notation
Characteristics
Global Warming Potential
R32
HFC (or R32 directly)
Modern, efficient
675 GWP
R410A
HFC Blend
Previous standard
2,088 GWP
R134A
HFC
Older technology
1,430 GWP
R22
HCFC
Phased out (CFC)
1,810 GWP (obsolete)
Reading Refrigerant Charge Information
Typical nameplate notation:
textREFRIGERANT: R32
CHARGE: 0.89 kg
or 1.95 lbs
What each specification means:
Information
Value
Purpose
Importance
Refrigerant type
R32
Identifies chemical
Must match exactly for refill
Charge amount
0.89 kg
Factory-filled quantity
Reference for maintenance
Charge weight
In pounds + ounces
Alternative measurement
Used in some regions
Critical Refrigerant Rules
✅ Always use the exact refrigerant specified on the nameplate
Never mix refrigerants (R32 + R410A = chemical reaction)
Incompatible with old equipment if upgrading refrigerant type
Different pressures/oil requirements per refrigerant
Refrigerant Pressure Standards
Each refrigerant operates at specific pressures. The nameplate may reference:
Pressure Specification
Metric
Meaning
High-side (discharge)
2.8-3.2 MPa
Compressor outlet pressure
Low-side (suction)
0.4-0.6 MPa
Evaporator inlet pressure
Design pressure
4.5 MPa
Maximum safe operating pressure
PART 6: COOLING CAPACITY SPECIFICATIONS
Understanding BTU and Kilowatt Ratings
The nameplate lists cooling capacity in two formats:
Format
Unit
Example (1.9-ton)
Conversion
British Thermal Units
BTU/hr
22,800
Standard US measurement
Kilowatts
kW
6.6-6.8
Metric measurement
Tons of refrigeration
Tons
1.9
Industry standard (1 ton = 12,000 BTU)
Capacity Ranges
Modern AC units don’t operate at a single fixed capacity. The nameplate specifies:
Capacity Range
Value (1.9-ton)
When This Occurs
Minimum capacity
1,600-2,000W (5,500-6,800 BTU)
Part-load, idle operation
Rated capacity
6,600W (22,800 BTU)
Full-load cooling
Maximum capacity
6,700W (22,900 BTU)
Turbo/high-speed mode
Inverter technology explanation: Traditional fixed-speed units run at 100% or 0%. Inverter units (DC) modulate between 10-100% capacity based on room temperature demands.
Cooling Capacity vs. Room Size
The 1.9-ton capacity suits specific square footage:
Room Size
Square Feet
1.9-Ton Adequacy
Notes
Very small
100-150
Oversized
Excessive capacity
Small bedroom
150-190
Optimal
Perfect match
Large bedroom
190-250
Excellent
Maximum efficiency
Small living room
250-300
Marginal
May cycle frequently
Large living room
300+
Undersized
Insufficient cooling
PART 7: PROTECTIVE COMPONENTS & SAFETY RATINGS
Fuse/Breaker Information
The nameplate specifies electrical protection required:
Typical notation:
textFUSE SIZE: 15A
BREAKER SIZE: 20A
MAX BREAKER: 25A
Professional competency in nameplate reading separates expert technicians from novices. Every repair, installation, and maintenance task begins with nameplate verification. This comprehensive guide provides the knowledge framework to read, interpret, and apply all information displayed on your AC unit’s nameplate with confidence and precision.
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