Cheap Quick Wire Connector Block

I needed some connectors for quick electrical circuits prototyping. I saw this 20Pcs CH2 Quick Wire Connector Terminal Block Spring Connector pack at very low price of €1.37. So I ordered them to see if they are any good for nay use. At least they should be OK for low voltage low current circuits if not anything else.  According to the videos they look useful and easy to use:

Excellway CH2 Quick Wire Connector Terminal Block Spring Connector LED Strip Light Wire Connector

Screwless wire spring clamp terminal block connectors.

Excellway – Quick Wire Connector – Banggood SKU290726

The Specifications looked OK:
Brand: Excellway
Model: CH2
Voltage: <250V
Electricity:<10A
Size: 20.16*17.06*12.23mm/ 0.79′*0.71*0.3 inch (L*W*T)
Insulation material: PE (fire-retardant insulation)
Wire range: -3.5 ~ 0.5mm2
Temperature: -40℃ ~ 150℃
Line pressing  frame material: Rolled steel

Apply for: motor, electrical control, power, household appliances, lighting, machinery and wire joints

I received the connector and everything looked good:

I tested the connector with several different wires, and I can agree that they seem to work pretty well and are easy to use.

But there were few details that make me wonder if they really match the specifications they have. One thing was that the construction was such that there was just a small metal spring and plastic case. It seems that this might not hold the high currents on real life situations, because cable connectors that really handle 10A usually have much more metal in them to carry currents and hold wires.

So I decided to test the connector if they really could keep the promises on specifications. I first decided to test the current handling of connector. So if they say less than 10A current recommended, the I expect connector should be able to handle 10A at least for short times with some heating. So I wired 10A AC current source (connected wires 1.5mm2 solid copper wires) to the connector. The end result was that the connector melted at 10A current in around one minute when I was trying to measure with IR thermometer how hot it gets.

View to bottom: He spring melted through.

Other thing that I noticed… On one side the metal part was pretty well isolated, but on the other side they are visible that can be touched with finger without too much trying. As such those do not feel very safe to be used on mains voltage installations.

Maybe the real current rating is much less than 10A.  Also tested at 5A current. The result was that in few minutes the connector heated up very much. My IR thermometer showed 68 degrees Celsius.

The product page mentioned for less than maximum 1500W load I tried that 1500W load (1500W/230V = 6.5A). At that current the connector melted in few minutes. Sorry Banggood but pressing the cable against end of steel spring and plastics can’t end with a low contact resistance! The resistance causes heating that starts melting plastic, that again increases resistance as contact force is reduced.

The product page said temperature range -40℃ ~ 150℃. I tested the high temperature with temperature controlled soldering iron set to 15o℃ (temperature verified with soldering iron thermometer).  Soldering iron at 150℃ melted the plastic quite easily. According to Wikipedia polyethylene melting point is typically in the range 120 to 180 °C.

Verdict:

According to my tests those connectors do not seem to be suitable or safe for high currents and mains voltage. They are potential fire danger because they are expected to melt before the mains panel fuse blows in on overload or short circuit situation.

For low voltage low current bench testing those could be useful. Currents up to 3A did not seem to cause too much heating, but there was already around 200 mV voltage loss over connector.

The low voltage low currents is no problem, but please don’t use them with high current and mains voltages.

This is a learning that don’t always trust the given specifications or CE mark stamped to product.

 

4 Comments

  1. Tomi Engdahl says:

    The problem on this cheap connector is that there is a thin spring metal pushing the wires against plastic. In a properly designed connectors quick connect spring loaded that can handle higher currents, there is metal spring pushing the wires against thick enough metal conducting part that can handle the current safely without heating too much. Like those connectors:

    Weidmuller Push-In Type Terminal Blocks P-Series
    https://www.youtube.com/watch?v=h5vuqEemq4w

    WAGO 224 Series — The Combined Lightning Connector
    https://www.youtube.com/watch?v=5gFFU2ZB0Ik

    Reply
  2. Tomi Engdahl says:

    Another type of quick connector that can handle high currents:

    wago compact connectors – Ultimate Handyman DIY tips
    https://www.youtube.com/watch?v=_KhBoxgyXgI

    Really like the Wago blocks.

    Wago products are fantastic. They are safe, time saving and endurable item for the electrical industry!

    The ratings on the connector block are just to cover their arses, they dont want people shoving loads of cables in and spurring off the connectors. Those connectors can carry way more than their rating.

    Reply
  3. Tomi Engdahl says:

    By the way it seems that there is no CE mark of the European Union in the product.
    The CE mark stamped to product seem to me to be “China Export” that bears a striking resemblance to the official European marking.

    Warning: don’t get confused between the CE Mark and the China Export Mark
    http://www.ybw.com/vhf-marine-radio-guide/warning-dont-get-confused-between-the-ce-mark-and-the-china-export-mark-4607

    In recent years we’ve all got used to the fact that if a product bears the CE mark, it’s safe. The reason for this assumption is that goods with CE marking demonstrate that they meet relevant and strict EU standards. This marking brings benefit to all in the supply chain and most notably, the consumer.

    Unfortunately, there exists a very similar mark which the majority of consumers and even sellers may see as the CE mark of the European Union but actually is something completely different. This “CE” mark means “China Export” and only means that the product was manufactured in China. It is believed by various organizations that this similarity is not a chance coincidence and that this expresses an aggressive approach to sell into the European market without the right standards.

    Reply
  4. Tomi Engdahl says:

    How to identify a Conformité Européenne mark vs a China Export mark
    https://starfishmedical.com/2017/01/02/conformite-europeenne-mark-vs-a-china-export-mark/

    The Conformité Européenne (CE) Mark

    The CE Mark is required on certain products that are sold in the European Economic Area (EEA). There are a number of compliance categories which cover different products. For most products companies don’t need to seek external inspections to use the mark. For products that require the mark, companies only need to ensure their product meets the applicable standards through testing, provide a declaration, and then place the mark on their product. Certain categories such as medical devices, require testing by an accredited third party called a Notified Body.

    The China Export Mark

    The China Export Mark means that the product was manufactured in China. There is no registration, testing, or auditing required in order to use it. The mark can be used arbitrarily by Chinese manufacturers. Products bearing the China Export mark vary in quality from being acceptable to outright dangerous in their design, and require constant vigilance on the end user’s part to be used safely.

    It is common practice for engineers to fully disassemble and inspect products of suspect quality, especially products which operate from AC mains power such as USB chargers, and battery chargers. Many engineers have personal anecdotes of using poorly performing products that appeared to have a CE mark, which turned out to be a China Export mark. One common shared experience is that of power supplies which become dangerously hot, sometimes to the point of melting their own casings.

    The Differences

    Given the vast difference in the meaning of these symbols, you need to be able to tell them apart.

    Conclusion

    There may be a large variation in quality between a legitimate CE-marked product and a look-alike, and it is important to be aware of what you’re buying. Otherwise, it might hurt. Of course being able to spot the difference between the two marks doesn’t quite save you from counterfeits, as there are vendors which place fake UL, CE, and other markings on their products. Constant vigilance on the part of engineers and supply chain management is needed to ensure you’re using the parts you think you are.

    Reply

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