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:
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.
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.