Recently, CCTV carried out spot checks on some plug in boards on the market:

1, line diameter detection

The line diameter refers to the cross-sectional area of the single wire in the inserted wire. The larger the wire diameter, the higher the electrical power that can be carried. This is the core index of the plug board.

The following red circle is the wire in the conductor:

According to the requirements of the new national standard, the line diameter must be above 1 square millimeters. Too thin line diameter will cause fever and high temperature in use because of high load power, which may cause spontaneous combustion.

By testing, only 1 batches of 15 batches of products purchased from the market meet the requirements. A cheap plug-in board, nominal diameter of 0.75 square millimeters, the actual detection line diameter is only 0.14 square millimeters.

In the experiment, the unqualified plug-in board inserted 4 simultaneous electrical appliances (up to 6 devices). After more than 10 minutes of electrifying, the cable part began to melt, emitting thick smoke, insulation skin cracking, and the temperature soared to 200 degrees Celsius. In this case, if you come into contact with curtains, carpets and other inflammable materials, it is very likely to have a fire.

2. Flame retardancy test of materials

The flame retardancy of materials includes two aspects: one is to use 650 degree centigrade hot wire as the heat source contact panel for 3 seconds, which requires no ignition or 30 seconds after ignition. The new national standard adds second tests, requiring that the contact plate should be exposed for 30 seconds, and it can not be ignited or extinguished after 30 seconds.

Only 5 batches of samples can meet the requirements.

Most products can be detected by hot wire, but they can not be detected by open flame.

The two type of simulation is two different risk scenarios. One is whether the overheating of electrical faults affects the plug board. One is whether the ignition of electrical appliances or other items will affect the plug board. Obviously, open flame detection has higher requirements for flame retardancy of products.

3. Leakage protection detection

The leakage protection detection of the plug board is divided into two aspects. One is whether the leakage protection device of the plug-in board is effective; and the two is whether the design of the plug-in board is effective or not to avoid accidental electric shock.

The leakage protection device of the plug board itself is mainly grounded wire. When touching the leakage electric appliance, the earth wire can lead the electric current to the ground, so as to prevent people from getting electric shock.

In the detection, some cheap plug-in board itself is two plugs, there is no grounding line; others are three plugs, but the grounding wire has only outer apron, there is no metal wire, it is just a display, it has no practical effect.

The design of plug-in board should avoid several problems.

1, the edge is too narrow, so that the electrical two plugs have an opportunity to insert a hole, a bare, causing leakage.

2. The inner live plug is close to the panel, and the plug does not need to be inserted completely.

3, there is no socket protection door, users, especially children, take sharp metal objects (such as pins, keys, etc.) easily inserted into the socket, resulting in electric shock.

The following red circle is part of the protective door:

There is no qualified sample for this test.

The main problem of cheap products is the ground wire Jerry building; other products are mainly because there is no installation of protective door.

The new national standard of plug line board was released in October 2015 and will be enforced in April 2017. Products that do not meet the requirements of the new national standard will not be listed for sale. Before that, consumers will have to identify themselves and choose quality products.

(source: CCTV13 weekly quality report)