1 Hardening SAFR SCAN from Electrostatic Shock

1.1 Introduction

Under some environments, SAFR SCAN can be subjected to electrostatic shock. While this is not something observed commonly in the field, there are certain environments where the physical or climatic environment results in higher frequency of electrostatic shocks.

Fortunately, SAFR SCAN devices are sufficiently robust that they are not permanently damaged by these electrostatic shocks but in some cases these events can result in device freezing. To mitigate this, SAFR SCAN has implemented proactive monitoring that enables it to recover quickly from these failures.

1.2 Grounding SAFR SCAN

To prevent elector-static shock freezing or restarting SCAN devices, it is important that SAFR SCAN device is properly grounded.

To accomplish this, connect PIN 5 on terminal block T1 to a ground so that if any static gets into the device, it has a place to discharge.

The chassis itself is connected to chassis internally which is tied to this ground connector on the board. By grounding PIN 5, you are grounding the SAFR SCAN chassis.

1.3 Grounding SAFR SCAN Housing

In some early SCAN units, outer aluminum housing did make appropriate electrical contact to the ground connector due to suboptimal paint application. This can make SCAN unit more easily susceptible by electro-static shock.

To correct this issue, a screw must be removed from the back of the unit and paint removed from the housing under the screw head. This will allow conductivity from the frame housing to the internal chassis which will then route through to the ground supplied on PIN 5 as described above.

This fix can be applied in the field and should only take a few minutes for each SAFR SCAN device. The device must be removed from the wall and unplugged during this operation.

Please follow the procedure below for applying this fix.

1.3.1 Procedure for grounding the SAFR SCAN housing

Tools Needed:

  • Sharp knife (to separate the vinyl backing from housing)
  • 1/16 in Hex Wrench or T6 Torx
  • Drill bit or a narrow tipped knife

Note: Units shipped after January 2024 do not have the paint application issue and do not require above procedure. Procedure

  1. Remove the vinyl backing from the back side of the SAFR SCAN housing. See diagram below.
    • Be careful not to cut or tear the vinyl backing as you perform this procedure. Keep the vinyl backing to reapply after the procedure.
    • It may help to use a sharp knife to being to separate the vinyl from the housing.
    • Once you have separated a corner, the rest should peel off. As you peel, take caution not to tear or bend the vinyl

A person cutting a knife

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  1. Use a 1/16 in. hex wrench or T6 Torx to remove 2 of the screws from the back of the unit.
    • Screws can be very tight and difficult to remove.
    • Use caution not to strip the screw by inserting the 1/6 in hex firmly into the screw
    • Do not use an incorrect size tool or changes of stripping the screw are high
    • If you do strip a screw, leave it secured and try an alternate screw
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  2. Using a drill bit that fits the tapered countersunk drill hole or a sharp knife to remove the paint from the surface and allow the screw head to make contact directly with the metal. Take care to remove sufficient amount of paint so that bare metal contact is established.

This should preferably be done with the unit facing upright, so the debris fall down away from the hole.

Screw hole before paint removal:

Screw hole after the paint removal:

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  1. When done, replace and tighten the machine screws and put the vinyl cover back on the back.

Grounding of the unit is only effective once this procedure is applied. Procedure even without unit grounding significantly improves device resilience to the electro-static shock.

The grounding of the device via the grounding PIN 5 from T1 connector will improve resilience even further and is expected installation guideline.

Following this procedure, with PIN 5 connected to a proper ground, SCAN device tested impervious to 15KV shocks applied to the chassis.

1.4 Earth Ground

Questions or comments about the documentation? Email us at safr-doc-feedback@realnetworks.com .

Its important to connect SAFR SCAN PIN 5 to a proper ground. In most cases, using the access control ground is sufficient. If SAFR SCAN is not being connected to an access control panel, an alternative earth ground should be employed. Simply attaching SAFR SCAN to a conductive material is not sufficient. A proper ground is one that provides a conductive path all the way to earth ground such the building electrical ground.