2N 9135130E, Руководство по установке

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2N TELEKOMUNIKACE a.s., www.2n.cz
®
Grounding Terminal Connection – Mandatory
Any person that gets in contact with may carry an electrostatic charge of 2N Helios
®
several thousands of Volts. Drawing one's finger near to the metal panel 2N Helios
®
may result in spark discharge. The purpose of the grounding terminal is to protect the
product against this discharge. The terminal carries the charge from the panel to the
ground directly, not through the
circuits. 2N Helios
®
Where no grounding cable is available, it is possible to connect the grounding terminal
with any of the telephone line terminals*). In some telephone systems one line
terminal is directly connected with the ground, the others carry current to the ground
through overvoltage protection.
Separate Backlight and Electric Lock Supply
Separate power supplies are necessary where the lock requires voltage higher than 12
V. In this case, an additional power supply (12 V) must be used to illuminate the
button backlight – see the figure below. Other reasons for such connection are the
effort to minimise consumption from the back-up supply (which supplies the lock, not
the backlight), or just that two weaker power supplies are available
Note
This connection eliminates direct connection of the line conductor onto the
panel because there is a protective element between the panel and the
grounding terminal.