How to Prevent Static Electricity When Using a Vacuum Cleaner in Dry Winter#
This explains how to prevent static electricity when using a vacuum cleaner in dry winter conditions.
Problem: I’m Afraid to Use the Vacuum Cleaner in Winter Because of Static Electricity#
It’s currently a dry and cold February winter in Korea. My previous vacuum cleaner broke, so I bought a new cordless one. At some point while using this vacuum cleaner, I started to feel a sudden, sharp electric tingling at the handle. Even wearing thick gloves while cleaning, the tingling sensation from the electricity continued. As this kept happening, it got to the point where I became afraid to use the vacuum cleaner.
What Could Be the Cause?#
At first, I suspected that there might be a manufacturing defect causing leakage near the handle of the vacuum cleaner. So I checked the battery’s output voltage and found it was 24 V — not high enough to cause severe tingling on the human body.
Curious if others were experiencing similar symptoms, I searched online. There were many cases of similar experiences, and it seemed common enough that the service center had registered it as an FAQ.
The cause turned out to be static electricity. The manufacturer’s FAQ explained that this symptom can occur when vacuuming over thick mattresses. And the service center reportedly does not offer any particular remedy. This phenomenon seems to have been happening for several years, and I was disappointed to see that it still hasn’t been fixed. Other manufacturers have the same issue too.
How to Prevent Static Electricity#
With no other choice, I decided to attach a grounding wire myself. I had some leftover electrical wire at home, so I cut it to an appropriate length.
I stripped about 3 cm of insulation from one end of the wire and taped the exposed metal wire to the vacuum cleaner’s handle. It’s important to make sure the metal wire is in tight contact with the vacuum cleaner.
That way, the static electricity flows through the wire instead of through the human body. Then I stripped about 5 cm of insulation from the other end of the wire. The metal wire on this side must touch the floor being cleaned.
To make sure it makes good contact with the floor, I attached several small nuts to add weight. With this, the grounding wire installation on the vacuum cleaner is complete.
Has the Static Electricity Disappeared After Attaching the Grounding Wire?#
I tested using the vacuum cleaner on the mattress to see if the static was eliminated. Oh! Fortunately, the static electricity completely disappeared.
The wire is a bit bothersome, but it’s better than feeling the sharp static shocks. The static phenomenon will likely go away once midwinter passes and humidity rises, but since this vacuum cleaner is also designed to be used on mattresses, the manufacturer needs to address this issue.
The Engineering Principle Behind Grounding Wires for Static Prevention#
Let’s look at the principle of how grounding wires prevent static electricity.
The reason static electricity is felt from the vacuum cleaner on the human body is that high voltage / micro current flows from the vacuum cleaner through the body to the floor, like the green path in the diagram below.
When a grounding wire is attached to the vacuum cleaner, current can flow not only through the human body but also through the grounding wire. As shown in the diagram above, there are now two paths (green and yellow) for current to flow from the vacuum cleaner to the floor. With the grounding wire attached, most of the current flows through the grounding wire instead of the human body. Let’s look at why this happens.
The amount of current flow is determined by voltage and resistance.
- As a formula, it’s
Current = Voltage / Resistance. - The unit for resistance is the ohm (Ω).
Human body resistance is thousands to millions of ohms, while wire resistance is less than 1 ohm. This means there is a difference in resistance of thousands to millions of times. Because of this resistance difference, the static electricity generated by the vacuum cleaner is hardly transmitted to the human body and is mostly transmitted to the grounding wire.
It can be easily calculated using the current divider rule. Let’s assume the following environment.
- Static charge: 100
- Body resistance: 1,000,000 Ω
- Grounding wire resistance: 1 Ω
Charge flowing through the grounding wire = 100 * 1,000,000 / (1 + 1,000,000) = 99.9999 Charge flowing through the human body = 100 * 1 / (1 + 1,000,000) = 0.0001
As shown, more than 99.99% of the static electricity is transmitted to the grounding wire and hardly any to the human body. By this principle, a grounding wire can prevent static electricity.