How To Disconnect A Solar Panel Under Load (Important Steps!)

Can you disconnect a solar panel while it is being loaded or used? You can, but you risk electrocution and significant damage to the connector.

There are times when you must disconnect solar panels, but never when they are creating electricity. 

When Can You Disconnect Solar Panels When They are Under Load? 

The answer is never. To do so would mean a significant risk of damaging the connector, solar panel, array, and yourself.

There are times when you must disconnect a solar panel, such as when it needs maintenance, but never when there is electricity passing through it.

Even shutting off the DC electricity can still leave you at risk. 

To be specific, you cannot turn off a solar panel. It will continue to create a reaction in the sun, even if not connected to the array.

That means solar panels create dangerous situations from many angles. 

In this article, we go over why you should never disconnect a solar panel while it is under load and what the dangers are if you have to disconnect a solar panel. Specifically, we touch on.

Connecting solar panels arrays - solar panels from behind with wires

What Are The Different Types of Electricity in Solar Arrays?

Solar arrays produce Direct Current (DC) so long as there is a circuit. As sunlight strikes the panel, it causes an elemental reaction.

A solar array would destroy most of the electronics in a home or business without an inverter. Most homes run on AC electricity.

The inverter’s job is to invert DC to AC so that the electricity produced by the array is usable in the house.

Some exceptions exist, such as appliances that work on DC or AC electricity. 

See also: Solar Panels Maintenance: Essential Tips for Optimizing Efficiency and Longevity

What Does an Inverter Do?

To change DC to AC, they use an inverter. Installers use a solar inverter attached to the array and the house.

Microinverters attach to the panel, String inverters attach to a line of panels, and hybrid inverters attach to the home, grid, and array.

The inverter inverts DC electricity to AC (Alternating Current) before the electricity flows to the house. If your solar array has a battery backup, solar batteries work with DC. 

What Are The Unseen Dangers of Solar Panel Maintenance?

To work on a solar panel, it must disconnect from the array. You cannot shut off a solar panel, but you can shut off the flower of energy.

While sunlight hits the panel, it will make a reaction. If the panel is under load and you disconnect it, the power from the array can arc.

When electricity arcs, it forms a ground, which can damage the panel’s connection, send electricity racing through you or across the entire array. 

DC and AC Energy – The differences

The Energy from the panel is DC, but if the panel is not disconnected, the inverter can feed AC electricity back through the line.

If your home connects to the grid, even more energy can feedback through the connections.

The situation can be lethal for anyone working on the array and quite damaging to the array. 

What Does Electricity Do to the Human Body?

When electrocution occurs, very hot electricity races from the point of contact through the body.

It travels along the blood vessels to the heart and out the grounding point, usually a leg or foot.

As it travels through the arteries and blood vessels, it burns them.

When it reaches the heart, which is also electronic, it causes the heart to stop beating.

Cardiac Arrest is Common

Most people who experience electrocution die of cardiac arrest. Even if help is available, it is difficult to get the blood to move because of the severe damage to the arteries and blood vessels.

If you survive, you face a long road to recovery.

Specific organs in the body have an electrical charge; those include the heart, brain, and nervous system. An electrical jolt or shock can damage each of these.  

Solar fuses on a wall

What Does Arcing Electricity Do to an Array?

As mentioned, electricity is hot. When arcing occurs, it melts wiring, metal, and damages other components.

If the arcing is isolated to just the panel, you will likely need to replace the panel.

If the panel has a microinverter, it will also need replacing. 

Damages the Panel or Inverter

If a string of panels connects to a string inverter, you risk damage to all the panels and the inverter.

Replacement can run several thousands of dollars, and you lose power from the entire string of panels.

In addition, damage to panels or inverters means reduced capacity from the array. 

Damage to the Entire Array

A severe arcing can damage the entire array and its components. When arcing lasts for a minute or more, the risk to the array is significant.

Melted wires, damaged solar batteries, damaged components such as inverters are all possible losses when arcing occurs.

Such a situation means no power production until the array repairs are complete. 

Is There Ever A Time When It Is Safe To Disconnect A Solar Panel Under Load?

No. The risk of arcing will always be present regardless of the situation. The disconnection of a solar panel should only occur when the panel is not under load.

The risk to human life and the array is far too significant. 

What Are The Reasons A Solar Panel Should Be Disconnected? 

There are a few reasons a solar panel needs disconnecting. The first reason is for maintenance. Sometimes a solar panel drops energy production.

For example, if the panel is part of a string, the lower power production per panel becomes the most energy the string can produce.

When that happens, a drop in energy for the array occurs. Maintenance would help increase and equalize power across all panels in the series. 

Eliminate Shading 

Another reason for disconnecting a panel is when it requires moving.

As mentioned above, if the energy production of one panel in a string drops, the energy production for the entire string drops.

Shading is an issue that may affect only one panel. By moving the panel to another location on the array, you lose the shading, and the energy production rises. 

Repairs to the Roof 

Disconnecting panels would occur if the roof on which they sit required repairs.

For example, broken or damaged roofing tiles from wind or weather would explain why you disconnect a panel.

Panel or Solar Component Replacement 

The last big reason a panel may need disconnecting is replacing the panel. Panels have lifespans; while some last for 25 years, others do not.

Within that category would replace components, such as microinverters or power optimizers, which sit under the panel. 

While there are situations where a solar panel would require disconnection from the array, that action should never occur when the panel is under load. 

Sources

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Elliot has 20+ years of experience in renewable technology, from conservation to efficient living. His passion is to help others achieve independent off-grid living.

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