Wiring; Power Input; Grounding - Recognition Systems HandKey II Installation And Operation Manual

HandKey II Installation and Operation Manual

Wiring

Four basic circuits typically connect to the Hand Reader:
•

Power Input

• Door Control Inputs and Outputs
• Networking and Communications
• Card Reader Input and Emulation Output
Power Input
The Hand Reader requires 12 to 24 volts DC (600 mA) or 12 to 24 volts AC (7 watts).
Power can be connected either to terminals 1 and 2 on the terminal strip or through
barrel jack J12.
Terminal 1 and the center pin of jack J12 are connected together. Terminal 2 and the
NOTE
sleeve of jack J12 are connected together.
A full-wave bridge rectifier input structure is used in the power supply of the Hand
Reader, making the polarity of terminals 1 and 2 irrelevant. Recognition Systems
recommends using terminal 1 for positive (+) voltage and terminal 2 for common (-)
for consistency. If J12 is used to attach power with the optional Recognition Systems
wall-mount power supply, terminal 1 will reflect +13.8 VDC (unregulated) and
terminal 2 will be power supply common.
Neither terminal 1 or terminal 2 is connected to the Hand Reader ground.
NOTE
It is not necessary to use a regulated external power supply to provide power to the
Hand Reader. AWG 18 wiring is recommended. Suitable wall mount power supplies
are available from Recognition Systems with either 110 VAC or 220 VAC input
ranges.

Grounding

Recognition Systems recommends that all Hand Readers be grounded with a solid,
reliable earth ground connection. This can be accomplished by attaching a separate
wire no smaller than AWG 18 between any of the Hand Reader's terminal strip ground
connections and a good, solid, earth ground source.
Terminal 2 is NOT directly connected to ground within the reader. Do NOT use this pin
NOTE
to establish earth ground. Use any one of the following ground terminals: 8, 10, 12,
14, 18, 20, 22, 24, or 26.
This connection establishes a common ground return point used to protect internal
semiconductor devices from ElectroStatic Discharge (ESD) and from external signal
line transients. It also provides a common signal level reference point between
externally networked Hand Readers. Recognition Systems recommends that the earth
ground source be identified by a qualified electrician familiar with electrical codes as
well as wiring and grounding techniques.
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