4
2.3) Electrical connections
To safeguard the operator and avoid damaging the components while you are wiring or plugging in the various cards:
under no circumstances may the unit be electrically powered.
• Power the control unit using a 3x1.5 mm
2
cable; should the distance between the unit and the earth connection exceed 30m, install an
earth plate near the unit.
• Use wires with a minimum cross-section of 0.25 mm
2
to connect extra-low voltage safety circuits.
Use shielded wires if the length exceeds 30m and only connect the earth braid to the control unit side.
• Do not make connections to cables in buried boxes even if they are completely watertight.
• If the inputs of the Normally Closed (NC) contacts are not used, they should be jumped with the “24V common” terminal except for the
photocell inputs if the phototest function is enabled. For further information please see the “PHOTOTEST” paragraph.
• If there is more than one (NC) contact on the same input, they must be connected in SERIES.
• If the inputs of the Normally Open (NA) contacts are not used they should be left free.
• If there is more than one (NA) contact on the same input, they must be connected in PARALLEL.
• The contacts must be mechanical and potential-free; no stage connections are allowed, such as those defined as "PNP", "NPN", "Open
Collector", etc.
• The constant resistance STOP input transmits an OK signal to the control unit if a circuit with a resistance of 8.2k
Ω
(e.g. a sensitive edge)
is connected between terminals 21-22.
!
2.2) Typical system layout
In order to explain certain terms and aspects of automatic gate and overhead garage doors systems, we will now illustrate a typical sys-
tem layout.
1.
Pair of photocells (PHOTO)
2.
Flashing light
3.
Key-operated selector switch
4.
Sensitive edge
5.
Control unit A100f
In particular, please note that:
• All the photocells produced by NICE feature a SYNCHRONISATION SYSTEM that eliminates the problem of interference between two pairs
of photocells (please consult the photocell instructions for further details).
• The “PHOTO” pair of photocells have no effect when the gate is opening, while they reverse movement when the gate is closing.
1
2
FOTO
3
1
2
FOTO
4
3
4
5
5
SLIDING GATE
OVERHEAD GARAGE DOOR
2a
2b
