Inside the SECOP SCE Hermetic Compressor: A Complete Exploded View and Parts Identification Guide

For technicians, engineers, and procurement specialists in the commercial refrigeration industry, understanding the internal anatomy of a compressor is not just academic—it’s essential for efficient maintenance, accurate troubleshooting, and reliable sourcing of spare parts. The SECOP SCE series hermetic compressor is a cornerstone in many refrigeration systems, known for its durability and performance. This article provides a comprehensive, journalistic breakdown of its internal components using a detailed exploded view, serving as your definitive visual and technical guide.

Decoding the Exploded View: A Systematic Walkthrough

An exploded view diagram is more than just a parts list; it’s a roadmap to the machine’s soul. It shows how individual components interact within the sealed “hermetic” shell, where the motor and compressor are welded shut to protect against refrigerant and moisture. Let’s navigate the key assemblies revealed in the SCE compressor diagram.

1. The Core Compression Assembly

This is the heart of the compressor, where mechanical motion translates into refrigerant compression.

• Piston (11) & Cylinder (Part of Crankcase 15): The piston moves within the cylinder bore, creating the vacuum and pressure cycles.
• Crankshaft (8): Driven by the motor, its rotational motion is converted into the piston’s reciprocating motion via the connecting rod (9) and wrist pin (10).
• Valve System: This critical assembly manages refrigerant flow. The suction valve (17) opens to draw in low-pressure gas. The discharge valve (18), held by its stopper (19), opens to release high-pressure gas into the discharge muffler.

2. The Electrical & Drive Assembly

Nestled beneath the compressor, this assembly powers the entire system.

• Stator (27): The stationary part of the electric motor, containing copper windings, housed inside the stator case (28).
• Rotor (25): Pressed onto the crankshaft (8), it rotates within the stator’s magnetic field.
• Hermetic Terminal (31): The vital electrical pass-through that allows power cables to enter the sealed compressor housing without leaking refrigerant.

3. Structural & Ancillary Components

These parts provide support, balance, and necessary functionalities.

• Compressor Housing (30): The iconic welded steel shell that contains all components.
• Suspension Springs (29): Isolate vibrations, preventing noise and wear from transmitting to the refrigeration cabinet.
• Oil Pump (26): Often a centrifugal type on the crankshaft, it ensures critical lubrication reaches the upper bearing (7) and other moving parts.
• Counterweight (6): Balances the rotating assembly to minimize vibration, secured by a screw (4) and sometimes accompanied by a slinger (5).

Complete SECOP SCE Compressor Parts Reference Table

For quick reference and cross-referencing with part numbers, here is a complete table of the components identified in the exploded view:

Item No.	Part Name	Primary Function
01	Compressor Cover	Protects internal parts, forms suction chamber
02	Suction Connector	Inlet for low-pressure refrigerant gas
03	Discharge Connector	Outlet for high-pressure refrigerant gas
04	Counterweight Screw	Secures the counterweight to the crankshaft
05	Slinger	Assists in oil distribution
06	Counterweight	Balances rotating assembly to reduce vibration
07	Upper Bearing	Supports the top of the rotating crankshaft
08	Crankshaft	Converts motor rotation into piston movement
09	Connecting Rod	Links the crankshaft to the piston
10	Wrist Pin	Pivot point connecting piston and connecting rod
11	Piston	Compresses refrigerant within the cylinder
12	Internal Discharge Tube	Channels compressed gas to the muffler
13	Screw	Fastens various components (e.g., muffler)
14	Discharge Muffler Gasket	Seals the discharge muffler connection
15	Crankcase	Main body housing cylinders and crankshaft
16	Valve Plate Gasket	Seals between crankcase and valve plate
17	Suction Valve	One-way valve for refrigerant intake
18	Discharge Valve	One-way valve for refrigerant outlet
19	Discharge Valve Stopper	Limits discharge valve movement
21	Cylinder Head Gasket	Seals the cylinder head
22	Suction Muffler	Reduces noise from suction gas pulsation
23	Cylinder Head	Covers the cylinder, part of compression chamber
24	Cylinder Head Screw	Secures the cylinder head
25	Rotor	Rotating part of the electric motor
26	Oil Pump	Circulates oil for lubrication
27	Stator	Stationary electromagnetic part of the motor
28	Stator Case	Holds and positions the stator
29	Suspension Spring	Vibration isolation mounting
30	Compressor Housing	Main hermetic (sealed) outer shell
31	Hermetic Terminal	Electrical connection into sealed housing
32	Base Plate	Foundation for internal assembly mounts

Why This Knowledge Matters for Your Business

Whether you’re a technician diagnosing a faulty discharge valve or a sourcing manager looking for a genuine SECOP crankshaft, this visual guide empowers you with precision. Correct part identification:

• Reduces Downtime: Enables faster, accurate diagnosis.
• Ensures Compatibility: Guarantees replacement parts match the exact SCE model specifications.
• Promotes Effective Communication: Allows clear reference between teams, suppliers, and clients.

The Grundfos CR20-06 A-F-A-E-HQQE is a vertical multistage centrifugal pump delivering 21 m³/h at 70.4 m head with a 7.5 kW IE3 motor, designed for demanding water boosting and industrial applications.​​
Its cast‑iron base, stainless‑steel internals and HQQE mechanical seal make it a durable, energy‑efficient solution for process water, HVAC, boiler feed and general pressure boosting systems.​

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Introduction

In modern industry and building services, stable water pressure is no longer a luxury but a basic requirement. The Grundfos CR20-06 A-F-A-E-HQQE has become one of the quiet workhorses in this field, combining compact vertical design with serious performance for installations where downtime is simply not an option.​

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Technical profile of the CR20-06

The pump in the photo is clearly identified on its nameplate as a Grundfos CR20-06 A-F-A-E-HQQE with a 7.50 kW motor operating at 50 Hz and about 2919 rpm.​​
It delivers a nominal flow of 21 m³/h at a rated head of 70.4 m, with a maximum head up to 88.4 m and a maximum operating pressure of 16 bar at liquid temperatures up to 120 °C.​

Main nameplate data

Item	Value
Pump type	CR20-06 A-F-A-E-HQQE
Rated power P2	7.5 kW
Frequency / speed	50 Hz / ≈2919 rpm
Rated flow Q	21 m³/h
Rated head H	70.4 m
Maximum head Hmax	88.4 m
Maximum pressure / temp.	16 bar / 120 °C
Shaft seal code	HQQE (single mechanical seal)
Pump orientation	Vertical, inline
Efficiency (pump)	≈75.6% (MEI ≥ 0.70)

​​

The pump uses a vertical, inline layout with suction and discharge on the same level (DN 50 flanged connections, PN 25 rating), simplifying installation in compact plant rooms and on rigid pipe manifolds.​
Its IE3 motor (size 132SB) offers motor efficiencies above 90% at typical loads, helping operators reduce long‑term energy costs.​

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Construction, materials and seal

The CR20-06 belongs to the widely used CR multistage family, where several impellers are stacked in series to build pressure while maintaining moderate flow.​
In this specific model, the base and pump head are in cast iron, while all wetted parts such as impellers and chambers are stainless steel AISI 304, providing a good balance between robustness and corrosion resistance for clean water duties.​

The HQQE mechanical seal is a single cartridge seal with silicon carbide/silicon carbide faces, EPDM elastomers and a stainless‑steel spring, designed for long service life and easy replacement.​
This configuration suits cold and hot water, mildly aggressive media used in HVAC and process plants, and reduces the risk of dry‑running damage during commissioning or transient operating conditions.​

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Typical applications and operating benefits

With its 21 m³/h at 70.4 m operating point, the CR20-06 is well suited to medium‑pressure boosting in commercial buildings, industrial wash and rinse systems, boiler feed for small to mid‑size boilers, and general process water circulation.​
Installers appreciate the inline design, which often allows direct replacement of older horizontal pumps without major changes to the pipework, while plant operators value the quiet operation and low vibration levels of the multistage design.​

From an energy perspective, the combination of high hydraulic efficiency and IE3 motor makes this model a strong candidate in projects where life‑cycle cost analysis is required or where regulations demand a minimum efficiency index (MEI ≥ 0.70).​
Paired with an external frequency converter, the CR20-06 can be turned into a variable‑speed booster, maintaining constant pressure in domestic water systems, process loops or district cooling circuits while cutting energy consumption during partial‑load operation.​

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Practical selection notes for engineers

When selecting a CR20-06 for a project, engineers typically start from the required duty point on the pump curve and verify that 21 m³/h at around 70 m head fits the system’s pressure losses, static height and safety margin.​
System designers also check NPSH requirements, temperature range from −20 to 120 °C, and maximum ambient temperature up to 60 °C to ensure trouble‑free operation in machinery rooms and outdoor installations.​

Because the pump offers a maximum operating pressure of 16 bar with PN 25 flanges, it can be integrated into higher‑pressure manifolds and ring mains, provided that upstream valves, fittings and vessels share compatible ratings.​
For users planning future upgrades, the CR range gives a modular platform: additional models and variants can be combined in parallel booster sets, or replaced one‑to‑one if system demand increases.

ZB38 5HP R404 MBP correspond à un compresseur scroll Copeland Emerson, modèle ZB38KQE ou ZB38KCE, puissance nominale 5 HP, conçu pour le fluide frigorigène R404A et destiné au service moyenne température (MBP = Medium Back Pressure).​

Caractéristiques typiques:

• Type: Scroll hermétique Copeland série ZB38 (Emerson).​
• Puissance: 5 HP, triphasé 380–400 V (suivant version TFD-551 / -558).​
• Fluide: optimisé pour R404A (souvent aussi compatible R507A, parfois R134a selon la plaque).​
• Application: réfrigération à température moyenne (MBP / MHBP), vitrines réfrigérées, chambres froides positives, etc.​
• Déplacement volumétrique: environ 14,4 m³/h; puissance frigorifique autour de 7–11 kW selon conditions (Te/Tc).​

Signification de ton code:

• ZB38 = série de compresseurs scroll réfrigération Copeland, taille « 38 ».​
• 5HP = puissance moteur nominale.​
• R404 = fluide R404A prévu pour ce modèle.​
• MBP = utilisation en température moyenne (évaporation typique -10 °C à +5 °C pour chambres froides positives, conservateurs…).​

Si tu précises les conditions de travail (Te, Tc, sous-refroidissement, surchauffe), il est possible d’estimer la capacité frigorifique exacte et vérifier si ce compresseur est adapté à ta chambre froide ou ton évaporateur actuel.

In commercial refrigeration, the compressor is more than just a component; it is the engine that decides whether a cold room runs smoothly or becomes a constant source of service calls. The ZB38 5HP R404A MBP scroll compressor is one of those models that technicians encounter again and again in supermarkets, butcheries, bakeries and restaurant cold rooms. Its popularity comes from a balance of capacity, efficiency and robustness that fits the core needs of medium-temperature systems.

What ZB38 5HP R404A MBP Really Means

When technicians talk about “ZB38 5HP R404A MBP”, they are compressing a lot of technical information into a short code.

• ZB38: Indicates a scroll refrigeration compressor series and displacement class, typically around 5 HP in the manufacturer’s lineup.
• 5HP: The nominal motor power, placing it in the range commonly used for medium-sized cold rooms and supermarket display lines.
• R404A: The main refrigerant for which the compressor is optimized, historically a standard in commercial refrigeration despite ongoing phase-down discussions in many markets.
• MBP (Medium Back Pressure): Specifies that the compressor is designed for medium-temperature applications such as positive-temperature cold rooms, fresh products, dairy and beverages, rather than deep-freeze low-temperature duties.

This decoding matters because each part of the designation tells the technician where the compressor can work safely, which refrigerant is acceptable and what kind of evaporating temperatures the system can handle without pushing the compressor beyond its envelope.

Typical Applications in the Field

A 5HP R404A MBP scroll compressor naturally positions itself in the heart of medium-sized commercial installations.

• Cold rooms for fresh meat, fruits and vegetables, where evaporating temperatures often range roughly between −10∘C−10∘C and +5∘C+5∘C, depending on the product and humidity control strategy.
• Supermarket wall cases and island cabinets for dairy, delicatessen and beverages, where multiple evaporators may be connected to a single condensing unit based on the ZB38 platform.
• Food-service equipment in hotels, central kitchens and bakeries, where reliability and quick recovery after door openings are more important than extreme low temperatures.

In these contexts, the ZB38 class compressor offers enough capacity to manage a significant thermal load while remaining compact, which is crucial when equipment must fit on rooftops, balconies or tight machine rooms in dense urban environments.

Why Scroll Technology Dominates This Segment

Scroll compressors like the ZB38 have progressively replaced many traditional reciprocating models in MBP applications.

• Fewer moving parts reduce mechanical noise, vibration and wear, which in practice often means fewer mechanical failures and smoother operation.
• The continuous compression process delivers stable mass flow, improving evaporator performance and temperature control inside cold rooms and cabinets.
• The compact, hermetic construction simplifies installation, reduces the risk of leaks at mechanical joints and helps manufacturers build more compact condensing units.

For technicians, scrolls are often easier to handle: electrical connections are straightforward, and the absence of complex valve mechanisms or external crankcase components shortens installation and troubleshooting time when compared with older piston designs.

Key Operating Parameters Technicians Monitor

Working with a 5HP R404A MBP compressor requires attention to several practical parameters, even if the data sheet is not in hand.

• Evaporating temperature: Usually in the medium range, technicians watch suction pressure to ensure it stays within the recommended envelope, avoiding both overloading and poor oil return.
• Condensing temperature: Condenser cleanliness, ambient temperature and fan control directly impact discharge pressure, compressor current and overall energy consumption.
• Superheat and subcooling: Correct expansion valve setting and a stable liquid line temperature help prevent liquid slugging at start-up and maintain the right mass flow through the evaporator.

In practice, a well-adjusted system keeps the compressor within its design envelope during the hottest days of summer, which is often where installations in Mediterranean climates are pushed to their limits.

Installation and Start-Up Best Practices

Even the most robust compressor can fail prematurely if basic installation guidelines are ignored.

• Cleanliness: Piping must be brazed with nitrogen purging and thoroughly evacuated to remove moisture and contaminants that can degrade oil and valves.
• Oil management: Proper piping design, especially at the suction line and oil traps on vertical risers, ensures oil returns reliably to the compressor shell.
• Electrical checks: Before energizing, technicians confirm supply voltage, phase sequence and proper overload protection, including verification of contactor and breaker sizing.

A disciplined start-up procedure—monitoring pressures, temperatures and compressor current over the first hour—usually reveals whether the system is healthy or if there are hidden issues like undersized condensers or incorrect charge.

Maintenance and Diagnostic Considerations

In daily practice, maintenance teams use a few key indicators to assess the health of a scroll compressor like the ZB38.

• Noise and vibration: Changes in sound signature can announce mechanical damage, liquid return or severe gas under-cooling at the compressor.
• Discharge line temperature: Excessive discharge temperature often points to high condensing pressure, low refrigerant charge or poor suction gas cooling.
• Oil color and level (if visible through an indicator): Darkened or acidic oil is a clear warning that the system has experienced overheating or contamination, and that deeper corrective action is required.

Regular cleaning of condensers, checking fan operation and verifying that defrost cycles are effective in evaporators can significantly extend compressor life by keeping operating conditions within design limits.

Where This Technology Is Heading

Although R404A has long been the standard for MBP commercial applications, environmental regulations are pushing the market toward lower-GWP alternatives and redesigned compressors.
Manufacturers are gradually adapting similar 5HP scroll platforms to new blends with different pressures and glide characteristics, while technicians increasingly need to be familiar with multiple refrigerants and their specific charge and oil requirements.
For users and contractors, this transition highlights the importance of good documentation, training and practical feedback from the field—an area where communities of technicians, independent platforms such as mbsmgroup.tn and projects like mbsm.pro, mbsmgroup and mbsmpro.com can play a useful role in sharing real-world experience and solutions.

Suggested exclusive images for this topic (you can create or photograph them yourself):

• A close-up of a 5HP scroll compressor label showing model code, refrigerant and electrical data.
• A medium-temperature cold room condensing unit with the compressor, condenser and control box visible on a rooftop or service balcony.
• A technician’s hand holding clamp meter and manifold gauges connected to a running MBP R404A condensing unit.
• A clean, well-lit cold room interior with product on shelves, showing air coolers on the ceiling and neat piping.
• A side-by-side photo of a scroll compressor and an older reciprocating unit on a workshop floor, demonstrating the difference in size and design.

 

Determining the cooling capacity of air conditioning and refrigeration compressors is fundamental for professionals in the HVAC industry. One of the key electrical values specified on compressor labels is the LRA (Locked Rotor Amps), which represents the maximum current drawn at motor start. Transforming this into tons of cooling provides a rapid and reliable way to size, diagnose, and upgrade systems.

What is LRA and Why Convert it to Tons?

• Locked Rotor Amps (LRA): The peak current when a compressor starts. It is vital for sizing electrical protection and understanding performance.

• Cooling Ton: Standard unit for cooling capability (1 ton = 12,000 BTU/hr).

The Simple Conversion Formula

For single-phase compressors, the modern, professional formula is:

$$Ton=LRA/36$$

Example:
If the compressor’s LRA is 54:
Ton = 54 / 36 = 1.5 Ton

Always use the division symbol (/) instead of horizontal lines for cleaner, easier-to-read formulas in technical documentation.

Benefits and Use Cases

• Quick Unit Sizing: Helpful when label information is limited or during site evaluations.

• Matching Electrical Loads: Ensures new or replacement units are compatible with existing infrastructure.

• Field Troubleshooting: Arms technicians with a fast check for expected capacity vs. measured electrical consumption.

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Summary:
This guide explains how to convert LRA into cooling tons using a direct and easy-to-use formula (LRA / 36 = Ton). It streamlines sizing, troubleshooting, and matching of commercial HVAC and refrigeration compressors, ensuring professional and efficient results in the field.

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Slug:
convert-lra-to-ton-hvac-modern

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Quick Reference Table: LRA / 36 = Ton

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By using this updated formula and professional writing style, technicians and engineers benefit from fast and transparent conversions that enhance reliability and accuracy in every HVAC task.

Winter Company for Refrigeration offers all refrigeration accessories sourced from top international brands including blue. Located in 6th of October City, Industrial Zone 2, Hamada Street, the company welcomes visits to explore their wide range of products. They can be contacted via phone numbers 01060032262, 01022856319, and 0155 522 6348 for inquiries and support.

Winter specializes in supplying high-quality refrigeration compressors, cooling units, and complete refrigeration packages for industrial and commercial use. Their products meet international standards for reliability and energy efficiency. The company has extensive experience servicing refrigeration systems in Egypt, especially within industrial zones.

Customers can rely on Winter for both product supply and technical maintenance support, making it a prominent choice in refrigeration solutions in the region. For detailed product specifications or tailored solutions, direct contact or visits to the company’s location are recommended, ensuring personalized service and expert advice.

This company is part of a global network that provides industrial refrigeration solutions, including ammonia and CO2-based systems with a focus on environmental protection and efficient cooling technology.winter-kaeltetechnik+2​

In summary, Winter Company offers trusted refrigeration products and services ideal for various refrigeration needs in Egypt’s industrial sectors, backed by internationally certified products and expert technical support.

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4. https://www.winter-company.com/en/contact/
5. https://www.facebook.com/groups/402355509267067/
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Specialists in installation, maintenance, and repair of cooling and freezing rooms, central air conditioning and split systems, control panels of all types, factory chillers of all kinds, and hotel and restaurant equipment. Contact us at 01287772722.

Performance Analysis of the BSA645CR Compressor with Horsepower Calculation

1. Introduction

The BSA645CR is a constant-speed reciprocating compressor designed for refrigeration and air conditioning systems using R134a refrigerant. It is commonly used in residential and light commercial applications due to its compact design, efficiency, and compatibility with standard voltage supplies.

This article provides a detailed overview of the BSA645CR compressor’s technical specifications, explains how to calculate its output horsepower (HP), and discusses its performance characteristics.

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2. Technical Specifications of

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Compressor Specifications:

1. Model Name: LG LBP MB88NA
   • This is the specific model number of the compressor manufactured by LG.
2. Power Consumption: 151 W
   • The compressor consumes 151 watts of electrical power during operation. This indicates the energy efficiency of the unit.
3. Horsepower (HP): 1/5 HP
   • The compressor has a motor rated at 1/5 horsepower , which is equivalent to 0.2 HP . This is a relatively small compressor, typically used in compact refrigeration systems or appliances like mini-fridges or beverage coolers.
4. Refrigerant Type: R600a
   • R600a (isobutane) is an eco-friendly refrigerant with low global warming potential (GWP). It is commonly used in domestic refrigerators and freezers due to its energy efficiency and minimal environmental impact. However, it is flammable, so proper handling is required.
5. Electrical Configuration: 1 Phase, 220V, 50Hz
   • The compressor operates on a single-phase power supply with a voltage of 220 volts and a frequency of 50 hertz . This configuration is typical for residential applications in regions like Europe, Asia, and parts of Africa.

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Applications:

Given the specifications, this compressor is likely designed for use in low-back pressure (LBP) systems. LBP compressors are typically used in:

• Household refrigerators
• Freezers
• Beverage coolers
• Compact cooling appliances

The R600a refrigerant further confirms that this compressor is intended for smaller, energy-efficient cooling systems.

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Key Considerations:

1. Environmental Impact:
   • R600a is a hydrocarbon refrigerant, making it environmentally friendly compared to older refrigerants like R134a or R22. However, it requires careful handling due to its flammability.
2. Voltage Compatibility:
   • Ensure that the power supply matches the compressor’s requirements (220V, 50Hz). Using incompatible voltage can damage the compressor or cause it to malfunction.
3. System Design:
   • Since this is an LBP compressor, it is optimized for systems with lower evaporating temperatures, such as freezers or deep-freeze applications.

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Conclusion:

The LG LBP MB88NA compressor is a compact, energy-efficient unit designed for small-scale refrigeration systems. Its key features include:

• Low power consumption (151W)
• Eco-friendly refrigerant (R600a)
• Compatibility with 220V, 50Hz power supplies
• Suitable for low-back pressure applications