Ricoh Static Shock
Ricoh’s Quality Assurance Center has investigated reports that some users of Ricoh MFPs have experienced an electric shock during use. It has been found that the cause is “Electrical Static Shock” which is harmless to humans.
We want to provide our users with further information on static shocks and the steps that can be taken to minimise its occurrence.
Why do I experience static shocks?
You may experience static shock when you touch a metallic door knob. This static electricity has the same mechanism as a lighting strike. For lightning, static electricity is generated in the clouds and discharged into the ground. This static electricity charged in your body is then distributed to the ground through the metallic door knob. You might feel some pain when the electric current is discharged from the fingers.
Generally, an electric potential difference (voltage) between your body and the door knob at that time is relatively high at several kV (kilovolts). However the discharging current value is very low, several (μA; micro-ampere). This means that unlike electric shocks by lightning, you just feel temporarily slightly uncomfortable.
A number of steps have been taken to ensure that risks are minimised for users if they receive an occasional electric shock by touching a copier and printer. Further to the International standards IEC (https://www.iecee.org), most printers installed in offices are classified as Class I devices and there are grounded metallic parts both inside and outside the machine.
When an electrically charged part of your body touches a machine, static electricity is safely discharged from the body to the grounded metallic parts and you may feel a small shock as a result. This is the same “static electricity” that you feel when touching a door knob or getting in or out of a car and touching certain car parts.
What affects static shock?
The environment you are in and what you’re wearing can affect whether you experience static shock. Your body can easily get electrostatically charged wearing shoes made of materials that do not conduct electricity, or clothes that easily get charged electrostatically.
You may also be more likely to receive a static shock if you are in a dry room where a rug or floor mat is placed, as it is difficult for electricity to discharge.
Is electrostatic discharge (ESD) harmful to the human body?
Electrostatic discharge (ESD) does not cause physical harm to a person, just potentially a minor annoyance.
How can I stop static shocks?
It is difficult to completely eliminate static shocks. However there are some minor adjustments your can take to reduce the occurrence and severity of these:
- Wear clothing made of non-synthetic materials such as polyester and nylon.
- Wear leather-soled shoes.
- Maintain the air humidity in the room to more than 50%. (In general, it is said that air humidity of less than 20% makes it easier to get charged electrostatically.)
- Place a rug made of anti-static electricity materials on the floor.
- Place a floor mat made of anti-static electricity materials on the floor in front of a copier.
- Use a chair which uses conductive materials.
- Avoid using synthetic materials such as polyester and nylon