Waterproof junction boxes are often used in construction sites, mines, ship cabins, outdoor electrical, communication, fire fighting equipment, steel smelting, petrochemical, electronics, electric power, railways, construction sites, mines, mining sites, airports, hotels, ships, large factories, coastal factories, unloading docks, and other equipment. They are one of the electrical wiring materials for electricians. Equipment installation sites are often wet and prone to flooding, often resulting in poor waterproof effects of junction boxes that can lead to instrumentation The problems such as the failure of the remote terminal unit (RTU) have solved the problems faced by the construction unit. So, what are the UL flame retardant ratings for junction boxes?
1. UL94HB: Horizontal combustion
This plastic can burn slowly but cannot self-extinguish. It is the lowest level of UL and is often used when vertical V0, V1, or V2 modes do not work. "If aging and UL testing is not yet complete, it is necessary to bring plastic products to the market, or use other methods to assess if it is not feasible. This method is used for testing. This is a temporary and frequent final evaluation method for plastics.
2. UL94 V0, V1, V2, V5: Vertical combustion
UL flame retardant classification is as follows:
UL94V0 and UL94V5 are plastic "insurance premium" classification methods that allow the sample to quickly self-extinguish after being ignited and the flame removed until there are no burning melt droplets within a certain time interval (that is, burning melt droplets fall on a cotton pad one foot below the test sample and cannot ignite the cotton). The flame length is required to be 3/4 inch, and each flammable test using UL94V0, V1, and V2 requires two combustions.
The L94V1 evaluation method is similar to V0, except that it requires a longer self extinguishing time. This test allows melt to drip onto the cotton pad, but does not ignite the cotton.
UL94V2 is the same as V1, except that it allows burning droplets to ignite cotton a foot below.
UL94 V5 is the most rigorous testing method. He designed the actual life of plastic products in a flame. The experiment requires a flame length of 5 inches, and applies 5 times of combustion to the test sample. During this period, no melting droplets are allowed to fall, no significant distortion is allowed on the test sample, and no holes are allowed to be burned out.