American Access Systems ProAccess 200sa - Manual (Page 32)

SK-ACP Installation & Operating Manual
F-1
APPENDIX F
SURGE PROTECTION FOR ACCESS CONTROL SYSTEMS
Access Control equipment is susceptible to damage from lightning, especially when installed outdoors.
Voltage spikes which travel through buried data cables, telephone lines or AC power lines can damage
Access Control equipment indoors, as well.
While nothing can protect equipment from a direct lightning hit, surge protectors can help to minimize the
damage caused by nearby lightning strikes. Surge protectors operate by connecting Transorbs or
Varistors from data lines to ground. Surge protectors have no effect on normal circuit voltages, but can act
quickly to divert large voltage spikes to ground and away from sensitive components.
Secura Key SA-Series Access Control Units are equipped with surge protection on all inputs and outputs.
PC’s, Printers, and Modems are designed for an indoor, office environment and do not have surge
protection. However, by properly installing aftermarket surge protection devices on all inputs and outputs,
these devices can also be protected from lightning damage.
Where to Install Surge Protection
• On the AC line voltage input to the PC.
• On the AC line voltage input to any transformer or DC Power Supply connected to a 28SA-Plus or
Modem.
• On RS-485 data lines connecting a 28SA-Plus Units or to a PC, Printer or Modem, using a
NET-CONV-P converter.
• On RS-232 data lines from SA Units (Readers) to PC’s, Printers or Modems.
• On Telephone lines connected to Modems.
Protect Both Ends of Data Lines
Surge Protectors should be installed at both ends of all Data Lines.
Wire Distance from the Surge Protector
You must locate the protector at least three wire feet away from the device being protected. The
additional wire resistance will dissipate the energy from leading edge of the spike. The wire can be coiled;
a three-foot physical distance is not required.
PREVENTING LIGHTNING DAMAGE