Why a refrigerator needs a separate machine โ€“ and when it can not do without it

A refrigerator in a garage or workshop is not just a household appliance, but critical equipment. It depends on the safety of products, medicines, and sometimes expensive chemical reagents (if you store, for example, auto cosmetics or consumables for painting). But connecting it through a common socket with lighting or tools is a gross mistake. Here's why:

First of all, surge when starting the compressor (starting current 3-5 times higher than nominal) can knock out a common machine, turning off the entire room. Secondly, long-term refrigerator on the same line with a welding machine or a powerful vacuum cleaner leads to overheating of the wiring. If the garage is not heated in winter, low-grade increase the load on the compressor โ€“ and without the right machine, the risk of fire grows exponentially.

A separate circuit breaker solves these problems: it protects the system. refrigerator It is not overloaded without affecting the rest of the electrician. But what kind of machine is it? Here everything depends on the power of the device, the type of network (220V or 380V) and operating conditions. Next, we will analyze each criterion in detail - with calculations, schemes and examples for different scenarios.

๐Ÿ“Š Where do you have a refrigerator?
In the garage.
In the house/apartment
In the dacha
In the workshop.
Another option

Criterion 1: The nominal current of the machine - how to calculate the power of the refrigerator

The basic parameter is numericalThis should be higher than the maximum current consumed by the refrigerator. The formula is simple:

I nom (A) = P (W) / (U (B) ร— cosฯ†)

Where:

  • ๐Ÿ”น P - the power of the refrigerator (indicated on the sticker at the back or in the passport). For most household models, this 100-250 Wfor industrial (e.g. industrial) Lieberr or Snaige- before 500-800 W.
  • ๐Ÿ”น U - the voltage of the network: 220B for single phase, 380B for three-phase.
  • ๐Ÿ”น cosฯ† - power factor (usually) 0.8โ€“0.9 for refrigerators.

Example of calculation for a refrigerator ATLANT XM 4021-000 (power) 140 W., cosฯ† = 0.85):

I nom = 140 / (220 ร— 0.85) โ‰ˆ 0.75 A

But it's current. When starting the compressor, the current briefly increases by 3-5 times (start current). Therefore, the machine must withstand:

I pusk = 0.75 x 5 = 3.75 A

The nearest standard denomination of the machine is 6A.. However, for reliability (taking into account possible voltage surges in garage networks), it is better to take 10A.. For industrial refrigerators (Snaige UF 380power 600 watts) will be required already 16..

๐Ÿ’ก

If the refrigerator is only indicated annuality (e.g., 300 kWh/yearDivide it by 8,760 hours per year to get the average wattage.

Criterion 2: Type of machine - B, C or D?

Automatic switches are divided into types by time-current (How long do they last before they are fired) For refrigerators, suitable:

Type of machine Response range What kind of refrigerators? Pluses Cons
B 3โ€“5 ร— I_nom Domestic (power up to) 300 watts) It works quickly with KZ, protects against jumps. May falsely trigger when starting the compressor
C 5โ€“10 ร— I_nom Any (optimum choice) Universal, rarely knocks out at launch Less sensitive to short circuits
D 10โ€“20 ร— I_nom Industrial (power from the 500 watts) It can withstand high initiation currents. It does not protect against small overloads.

For most cases (including garage refrigerators) it is optimal. type-C. It reliably protects against short circuits, but does not work with normal start-up of the compressor. Type B is suitable only for low-power models (for example, for the use of Birusa 54), and type D for industrial installations with three-phase connection.

โš ๏ธ Attention: If there is already a machine in the garage D You put a refrigerator on the general line, and you add a refrigerator. Don't connect him to this line.. The risk of overheating of the wiring with simultaneous operation of the refrigerator and, for example, a welding inverter increases significantly.

Criterion 3: Single-phase or three-phase automatic?

Most refrigerators are operated by 220B (single-phase network), but industrial models (e.g., Lieberr LKv 500 or Snaige UF 380may require 380B (three-phase network). How to determine which machine is needed:

  • ๐Ÿ”Œ Look at this. refrigerator-fork: if 3 pins (phase, zero, earth) - single-phase (220B) if 5 pins are three-phase (380B).
  • ๐Ÿ“„ Look for the inscriptions on your passport: 220โ€“240V or 380โ€“400V.
  • โšก Check it out. enter-machine in the garage: if it is three-phase (4 wires: 3 phases + zero), you can connect the refrigerator to the main station. 380B.

For single-phase refrigerators, use monopole (The second is preferable, since it breaks both phase and zero). For three-phase, tripole (if there's a neutral). Example of a three-phase refrigerator connection scheme:



L1 โ†’ Automatic (Pole 1) โ†’ Refrigerator (Phase A)


L2 โ†’ Automatic (Pole 2) โ†’ Refrigerator (Phase B)


L3 โ†’ Automatic (Pole 3) โ†’ Refrigerator (Phase C)


N โ†’ Automatic (Pole 4, if any) โ†’ Refrigerator (Neutral)


Grounding (bypassing the machine!)
โš ๏ธ Attention: If there is no grounding in the garage (PE), and the refrigerator is three-phase. Don't plug it in. without a grounding circuit. This violates the PUE (P.1.7.39) and is life-threatening. Use a leaky RCD. 30 m..

Criterion 4: Brand and series of machines - what to choose for the garage

There are hundreds of models of machines on the market, but only proven series from reliable brands are suitable for garage conditions (dust, humidity, temperature changes). Here's the short rating:

Brand Series Nominations (A) Pluses Cons
ABB S200 6โ€“63 Impact-resistant body, resistance to corrosion More expensive than analogues by 30-50%
Schneider Electric Acti9 iC60 6โ€“125 Accurate time-current characteristic, suitable for low temperatures Fakes are common
Legrand TX3 6โ€“63 Compact size, easy installation Plastic is less durable than ABB
IEK BA47-29 6โ€“63 Budget option, widely available The quality of the assembly is worse than European brands

For a garage or workshop is optimal ABB S200 or Schneider Acti9 - they're holding up. temperature from -40ยฐC to +70ยฐC and are protected from dust (IP20 and above. If the budget is limited, take it. Legrand TX3Check the certificates (many fakes). From IEK It is better to refuse if the refrigerator is expensive or stores critical products.

Check the marking (the brand logo and denomination should be)

Make sure that contacts are not sluggish

Compare weight โ€“ fakes are 20โ€“30% lighter

Ask for a certificate of conformity GOST R 50345-2010->

Criterion 5: Switching to the machine?

Device for protective disconnection (art.CCD) is not a mandatory but highly desirable element of the scheme. It protects you from leakagewhich may arise from:

  • ๐Ÿ”Œ Damage to the insulation of the wire (for example, the cable was worn from the vibration of the compressor).
  • ๐Ÿ’ง Getting moisture in the socket or on the body of the refrigerator.
  • โšก Failures of TENS (in models with function) No Frost).

For the refrigerator, an ultrasound with parameters is suitable:

  • ๐Ÿ”น Leak current: 30 m. (It is safe for humans, but it will not be false).
  • ๐Ÿ”น Nominal current: a step above the machine (for example, if the machine 10A.- We'll take the RCD. 16.).
  • ๐Ÿ”น Type: AC (for conventional refrigerators) or A (If there is an electronic control).

Connection diagram:



The Automatic Phase โ†’ UZD โ†’ Refrigerator


Zero to the Refrigerator


Refrigerator (bypassing the machine and RCD)
โš ๏ธ Attention: If there is no grounding in the garage, the RCD becomes mandatory. Without it, when the current leaks to the body, the refrigerator will remain under voltage, which is deadly dangerous.
What happens if you don't put an ultrasound?

In case of a leakage of current (for example, due to a damaged wire), the refrigerator case may be energized. If you touch it and a grounded object (for example, a metal workbench), a current will pass through the body, which can lead to fibrillation of the heart. The RCD will shut down power in 0.03 seconds, saving a life.

Connection schemes: 3 options for different conditions

The choice of circuit depends on where the refrigerator is installed and what electrical infrastructure is already in the room. Let's look at three cases:

Scheme 1: Separate line from the shield (optimum for the garage)

The ideal option is to hold out. single-cable from the introductory panel to the refrigerator. Use this:

  • ๐Ÿ”น Cable: VVGng LS 3ร—1.5 mm2 (for power up to) 3.5 kW).
  • ๐Ÿ”น Automatic: Type C 10A (for a household refrigerator).
  • ๐Ÿ”น UZ: 16A, 30mA, Type A.

Scheme:



Introductory machine โ†’ Counter โ†’ Automatic machine 10A โ†’ UZO 16A / 30mA โ†’ Socket for the refrigerator

Scheme 2: Connection to a common line (if a separate line cannot be held)

If a separate line is not possible, connect the refrigerator to the existentBut with the rules in mind:

  • ๐Ÿ”น Replace the common machine with a more powerful one (if the line is designed for the 16.And the fridge pulls 10A.- Leave the room.
  • ๐Ÿ”น Install. localization only on the refrigerator socket (for example, ABB Basic 55 socket).
  • ๐Ÿ”น Do not connect to this line tools with high initiation current (welding apparatus, compressor).

Scheme 3: Three-phase connection (for industrial refrigerators)

For models on 380B (e.g., Snaige UF 380) use:

  • ๐Ÿ”น Cable: VVGng-LS 5ร—2.5 mm2 (5 lived: 3 phases + zero + earth).
  • ๐Ÿ”น Automatic: tripole 16A type C.
  • ๐Ÿ”น UZ: four-pole 25A, 30mA, type A.

Scheme:



L1 โ†’ Automatic (Pole 1) โ†’ RCD (Pole 1) โ†’ Refrigerator (Phase A)


L2 โ†’ Automatic (Pole 2) โ†’ RCD (Pole 2) โ†’ Refrigerator (Phase B)


L3 โ†’ Automatic (Pole 3) โ†’ RCD (Pole 3) โ†’ Refrigerator (Phase C)


N โ†’ RCD (Pole 4) โ†’ Refrigerator (Neutral)


PE โ†’ Grounding
๐Ÿ’ก

For three-phase refrigerators, check them out. phasement before the connection. Improper phase alternation (e.g. A-B-C instead of A-C-B) can cause the compressor to fail.

Frequent Mistakes and How to Avoid Them

Even experienced electricians sometimes make mistakes when connecting refrigerators. Here are the most common:

  1. ๐Ÿ”Œ Using a machine without RCD in the garage without grounding. Risk: Electric shock from leakage. Decision: Set an RCD or make a local grounding (a circuit of metal rods).
  2. โšก Connecting the refrigerator to the line with the welding machine. Risk: overload and fire. DecisionSelect a separate line or use a machine with high-cut (Type D).
  3. ๐Ÿ”„ Improper phase alternation with three-phase connection. Risk: Compressor failure. Decision: Check the phasing indicator M417 or multimeter.
  4. ๐Ÿ“‰ Ignoring the initiation currents. Risk: The machine knocks out at launch. Decision: Take a machine with a margin (for example, 16. instead 10A.).

Another typical problem. phony-positive. If it knocks out for no apparent reason, check:

  • ๐Ÿ”น Insulation condition of the cable (microcracks are possible).
  • ๐Ÿ”น Correctness of connecting zero (it must pass through the RCD).
  • ๐Ÿ”น Presence jolt-filter In the refrigerator (they can create leaks).
๐Ÿ’ก

If the RCD works when you turn on the refrigerator, try replacing it with type-A (It is less sensitive to the electric currents of electronic boards.)

FAQ: Answers to Frequent Questions

Can I connect the refrigerator through an extension cord?

Technically, but only temporarily and subject to the rules:

  • ๐Ÿ”น The extension cord should be with grounding and a wire-crossing 1.5 mm2.
  • ๐Ÿ”น The length of the cable is no more 5 meters (otherwise, a drop in tension).
  • ๐Ÿ”น Do not connect other devices to the extension.

For permanent use lay out a separate line.

What machine to put in the refrigerator ATLANT MXM 1705 (power 120 watts)

Calculation:

I nom = 120 / (220 ร— 0.85) โ‰ˆ 0.64 A

I pusk = 0.64 ร— 5 โ‰ˆ 3.2 A

The optimal machine: 6A type C. UZ: 10A, 30mA, type A.

Should I put a difautomat instead of a machine + RCD?

Difautomatic (automatic + RCD in one case) is convenient, but has disadvantages:

  • โœ… Pros: compact, easier installation.
  • โŒ Cons: more expensive, when triggered it is unclear what caused (KZ or leak).

Better for the garage. split-up (Automatic + ultrasound), as it is easier to diagnose.

What to do if the machine knocks out when the refrigerator starts?

Causes and solutions:

  1. The machine is weak.Replace with a larger denomination (e.g., with a 6A. on 10A.).
  2. Start current is too high: Use the machine type-D Or a smooth starter.
  3. The compressor is defective.Check the starting relay (may stick).
Can I connect the refrigerator to the line with the machine? 25A.if it is designed to 10A.?

Technically, but undesirablely. Problems:

  • ๐Ÿ”น Automatic. 25A. will not protect the refrigerator cable from overheating (if, for example, it is shortened inside the device).
  • ๐Ÿ”น With KZ in the refrigerator, the wiring will burn, and the machine will not work.

Solution: Install sub-machine 10A. Just in front of the fridge.