Long Sun launched out a new UFO high bay THOR series in last Autumn, and it becomes another HOT in such a short time although we are facing the big challenge from going-do market due to the Covid-19. However, there is still doubt from some customers because we adopt non-isolated driver. People usually think it is not good enough and prefer to traditional isolated driver.

An isolated driver is that the driver is electrically isolated from the rest of the circuit which is power on. This means there is a transformer, which make power is transferred from the input end to the output end without a direct electrical connection between primary and secondary coils.

While, for a non-isolated driver, AC end 110V or 220V is connected directly to the electronic circuits, that is to say input and output end is connected directly through the electronic components without transformer, but it doesn't mean it's not a safe product.

Let us take Long Sun THOR series high bay for example.

Compared to isolated driver, there is extra requirement on non-isolated driver,

1. Withstand voltage requirement:

Withstand voltage between aluminum PCB and housing is objected because isolated driver is completely isolated from input and output. Since output terminal and the input terminal are directly electrical connected, it is necessary that the withstand voltage between PCB and housing meet the minimum Class 1 luminaire requirements, 1500Vac withstand voltage input to the housing is required.

2. Lightning shock requirement

In an isolated LED driver the Input (AC side) & Output (LED side) are separated by power transformer which provides galvanic isolation. In a non-isolated LED driver, there is no power transformer. Non-isolated refers that output terminal and the input terminal are directly electrical connected. It require 3000V withstand voltage on the PCB to meet 4KV surge shock.

3. Creepage distance requirements:

The output voltage for isolated driver is low so there is no special requirement for the output creepage distance below 50V. The output voltage for non-isolated driver is relatively high. Generally, 3.2MM is minimum distance when voltage range from 50V to 250V. LongSun’s is more than 3.5mm.

If one product with non-isolated driver meet the requirement listed as above, it’s a safe product. 

Also, for a high bay, Long Sun adopts the following step to guarantee the safety.

• Drivers are approved with UL and TUV certification. Test reports are available.
• The output end will be isolated by the insulated PC lens, which cannot be touched output end, so there will be no potential safety hazard.
• Highbay light are belong to Class 1 lighting line, it must be grounded, if the driver generates leakage to the light, the enclosure will be led to the ground by the ground wire of the lighting, so there is no risk of direct contact with the housing.
• Long Sun will test the housing of each product, about the voltage resistance and grounding resistance to ensure that there will be no electricity leakage of the housing.

In the actual operating environment, high bay light fixtures are installed on the high place, people won’t touch the lighting directly after installation, so there will be no potential safety hazard.

Non-isolated LED driver has higher power efficiency than isolated one because the transformer losses are avoided. The electrical efficiency can reach up to 95% while isolated power supply is 88% only. At the same time, the friendly cost is a very important reason for our choice.

Long Sun sold out thousands of high bay in past three years, and the 6 defective rate indicates that the non-isolated driver solution on LED high bay light is practical and feasible. Visible, we will see the non-isolated driver would be more and more popular in future market.