Creating a drawing or schematic diagram of a refrigeration unit is a task that may be required both by students of technical universities and by repairmen of household appliances. A well-designed visualization helps you understand the operating principle of the device, diagnose faults, or design your own unique unit. Unlike an artistic drawing, a technical diagram requires strict adherence to standards and a logical sequence of elements.
You need to clearly distinguish between an artistic sketch, which shows the appearance, and circuit diagram, which shows internal connections. Errors at the design stage can lead to a misunderstanding of the operation of the compressor or thermostat, which in real operation can lead to equipment breakdown. Therefore, the approach must be systematic and attentive to details.
In this article we will analyze the main stages of creating a drawing, consider the necessary tools and symbols. You will learn how to correctly place elements on a sheet and connect them with lines according to ESKD standards. Attention to standards is a key factor for success in technical drawing.
Preparation of the workplace and selection of toolsBefore you start drawing, you need to organize the work space and prepare a set of tools. To create a high-quality diagram, you will need thick A4 or A3 paper, a ruler, a set of pencils of different hardnesses and an eraser. If you plan to create a digital version, you will need specialized programs such as AutoCAD or Visio, but first it is better to master the manual method.
The choice of pencil plays a critical role: for drawing center lines and auxiliary markings, use a hard lead (marking H or T), and for the main contours - soft (B or M). This will make it easy to correct errors in the early stages without leaving deep grooves on the paper. The cleanliness of the lines directly affects the readability of the future document.
⚠️ Attention: Do not use ballpoint pens for drafts, as they cannot be erased without damaging the structure of the paper, which will make the diagram sloppy and difficult to read.
It is also important to ensure good lighting of the workplace. The light should fall from the left and front so that the hand does not cast a shadow on the drawing. Workplace ergonomics Reduces fatigue and increases the accuracy of movements when drawing small parts, such as relay contacts or thermostat contacts.
Design analysis and selection of circuit typeBefore drawing the first line, you need to understand what kind of diagram you are drawing. There are different types of display: structural, functional, fundamental electrical and installation. To understand the operation of a refrigerator, you most often need a circuit diagramwhich shows the full composition of the elements and the connections between them.
Start with an analysis of the physical device. The refrigerator consists of a compressor, condenser, evaporator, capillary tube and control system. In the electrical diagram, we are primarily interested in the motor-compressor, start-up relay, thermostat and lighting lamp. Understanding the physical logic of operation refrigeration circuit will help to correctly position the elements on paper.
When choosing the type of diagram, focus on the purpose of your drawing. If you need to show the path of the refrigerant, a hydraulic diagram is drawn, where the compressor and heat exchangers are represented by symbols. If the goal is electrical repair, then the focus shifts to power circuits, motor windings and temperature sensors. The schematic diagram does not reflect the actual arrangement of parts in the case, but shows only logical connections.
Conventional graphic symbols of elementsThe basis of any technical drawing is the use of standardized symbols. In Russia and the CIS countries, GOST 2.700-2011 is in force, which regulates conventional graphic symbols in electrical circuits. Without knowledge of these symbols, your drawing will only be understandable to you, but not to a specialist.
The central element of the diagram is the compressor electric motor. In the drawings it is indicated by a circle with a letter M inside, often supplemented with winding symbols. Starting and protective relays are represented by specific contacts that open or close under certain conditions. The thermostat (thermostat) looks like a switch with a sensitive element.
- 🔌 Socket and plug —connection points to the 220V network, indicated by a semicircle with contacts.
- 💡 Light lamp —a circle with intersecting diagonals inside, often connected to the door limit switch.
- 🌡️ Thermoregulator —contact with a temperature sensitivity symbol, opens the circuit when the set temperature is reached.
- ⚡ Starting relay - a coil or contact that provides short-term connection to the starting winding of the engine.
The table below will help systematize the basic symbols that you will encounter when drawing a diagram of a modern refrigerator.
| Element | Designation on the diagram | Function |
|---|---|---|
| Compressor | Circle with M | Refrigerant compression |
| Thermostat | NC contact | Temperature control |
| Fuse | Rectangle with line | Overload protection |
| Lamp | Circle with a cross | Camera lighting |
Building an electrical circuit diagramThe drawing process begins with drawing the power supply. Draw two vertical or horizontal parallel lines indicating phase and zero. Lines will diverge from them to all energy consumers. This is the foundation on which you will “build up” the rest of the device’s operation logic.
Next, sequentially connect the control elements into the circuit. The first is usually the thermostat, which breaks or closes the common power circuit of the compressor and lamp (if there is no separate door switch). After the thermostat, the circuit bifurcates: one branch goes to the lighting lamp (through the door switch), the other to the compressor through the start relay.
☑️ Stages of constructing a circuit
When connecting elements, use straight lines, avoiding unnecessary bends. Wire connection points are indicated by a bold dot. If the lines simply intersect without connection, the point is not placed. Schematic readability It is more important to save space on the sheet, so arrange the elements evenly.
⚠️ Attention: When drawing a grounding circuit, make sure that the compressor housing and metal parts of the refrigerator have a direct connection to the grounding circuit, this is critical for safety.
Features of the image of the refrigeration circuitIf your task includes not only electrics, but also the physical circuit of freon movement, the approach changes. It is important to show a closed loop here. Start with the compressor, from it there is a discharge tube to the condenser (coil on the back wall), then a filter drier, a capillary tube and finally evaporator inside the chamber.
For the tubes, use solid lines, and for the coils - wavy or spiral areas. It is important to show the direction of refrigerant flow with arrows. Unlike an electrical diagram, there are no standard GOST symbols for each part, so a realistic or simplified technical representation of the components is often used.
Secrets of the image of a capillary tube
A capillary tube on diagrams is often depicted as a very thin line, sometimes with a gap or a special narrowing symbol, to emphasize its throttling function pressure.
Pay special attention to the filter drier. In diagrams it is often designated as a cylinder embedded in the line between the capacitor and the capillary tube. Understanding where the change in the aggregate state of freon occurs (evaporation and condensation) will help you correctly label the zones in the drawing.
Digitalization and modern drawing toolsIn the modern world, manual drawing is becoming a thing of the past, giving way to CAD systems. Programs like Microsoft Visio, CorelDRAW or specialized electronic editors (for example, sPlan or EasyEDA) allow you to create diagrams faster and more accurately. They have built-in libraries of ready-made symbols, which eliminates errors in proportions.
When working in digital format, use layers. Place the body outline on one layer, the electrical circuit on the second, and the signatures and dimensions on the third. This will allow you to hide or change individual parts of the drawing without the risk of damaging the entire composition. Save your work in vector formats (SVG, DXF) so that when scaling the clarity of the lines is not lost.
Typical mistakes when drawing up diagramsEven experienced engineers sometimes make mistakes that can confuse those who read the drawing. One of the most common mistakes is a violation of the logic of serial and parallel connections. For example, the lighting lamp in a refrigerator should only light when the door is open, regardless of the operation of the compressor, so it is connected in parallel to the main circuit, but through its own switch.
Another common problem is the lack of designations of ratings or types of elements. Just drawing a square is not enough; you need to sign what it is, for example TDM-1 or indicate the resistance of the windings. Without a text reference, the diagram loses its engineering value and becomes just a picture.
⚠️ Attention: Do not confuse normally open and normally closed relay contacts. In a state of rest (without current), the contacts of the starting relay are open, and the contacts of the thermostat are closed (if it is warm in the chamber).
Checking and verification of the drawingAfter completing work on the circuit, it is necessary to thoroughly check it. Use the “trace method” with your finger or cursor from the power input to each consumer and back to zero. Make sure that there are no breaks where they should not be, or short circuits. Logical integrity is the main quality criterion.
Compare your drawing with factory documentation for similar models of refrigerators, for example, Atlant or Indesit. This will help identify missing items, such as a thermal motor protection relay or a fuse in the thermostat circuit. A good circuit should be self-sufficient to understand the principle of operation.
How to check the circuit for errors?
Take a red pencil and circle the phase wire, blue - neutral. Make sure that no element is left unconnected to both poles in operating mode.
In conclusion, it is worth noting that the skill of reading and drawing diagrams comes with practice. Start with simple single-compressor models, then move on to No Frost systems with their complex defrost circuits and fans. Constantly improving your drawing skills will allow you to better understand the structure of household appliances.
Do you need to know the exact dimensions of parts to draw a diagram?
No, the electrical circuit diagram does not require adherence to scale. Only the logical connection between elements is important. Dimensions are needed only for the wiring diagram or housing drawing.
What file format is best to choose to save a digital diagram?
For further editing it is better to use source program formats (for example, .vsdx for Visio). PDF is ideal for publishing or printing, since it saves the layout on any device.
Is it possible to draw a diagram of a refrigerator in a graphic editor like Photoshop?
Technically it is possible, but not recommended. Raster editors do not have binding functions and component libraries, which will make the process long and the result unclear when scaling.
Where can I find official GOST symbols?
Current standards can be found in documents of the GOST 2.700–2.799 (ESKD) series. They are available in electronic libraries of regulatory documents or specialized technical literature.