Grounding guidelines for IDTECH readers to optimize the ESD protection

Often, people walking on carpet and simply moving around will pick up and carry a static electrical charge with them. This is especially true in low-humidity dry areas. The moment they insert or swipe the card through a magnetic card reader, an Eelectrostatic Ddischarge (ESD) can occur. If the reader has not been properly grounded, the internal electronic components may be severely damaged. 

Step-by-step guide

You can check that your reader is properly grounded using a multi-meter by testing for continuity from the reader’s chassis ground to the earth-ground prong of the 3-prong power plug that goes into the wall outlet. It is not sufficient to rely on the grounding through the USB or COM ports going into the host, ID Tech strongly recommends that the readers be grounded using a grounding wire connected to a grounding pad on the main PCB and to the metal chassis of that cabinet that is in turn grounded to earth ground.

For best ESD protection, consider connecting the reader’s chassis ground to the host or the KIOSK’s metal housing within the shortest possible distance. The wire connects to the reader Chassis Ground Pad to the nearest Host Chassis Ground Pad. This provides a fast discharge path and helps to enhance the reader's ESD immunity.  

The grounding wire can be made with a 24-gauge wire with terminal Rings (TE P/N: 31340; DigiKey P/N: A27149-ND) on both ends for easy connecting. See the attached pictures for the wire with the terminal rings and datasheet for TE: 31340, as well as the pictures showing the grounding pad location on various IDTECH readers. For SecureMOIR, the SPTE series, you can use any one of the 3 metal pads where the 3 screws are on the reader’s PCA; For SpectrumAir, the SPTS series, use the metal pad in the middle of the PCA, for the swipe series, use the lug which connects to the metal wear plate on the bottom of the rail).

TE 31430.pdf