Connecting The Photocells; Photocell Testing - Nice Mindy A824 Instructions Et Recommandations Pour L'installateur

3) CONNECTING THE PHOTOCELLS:

Normal connection of the photocells foresees a power supply common for all transmitters and receivers and connection of the
contact on the relevant inputs PHOTOCELL and PHOTOCELL1, as shown in Fig. 2A

3.1) PHOTOCELL TESTING:

This particular device deserves a detailed description.
It is the best possible solution, in terms of reliability, for safety devices.
Each time a manoeuvre is activated the relevant safety devices are checked and only if everything is in proper working order,
will the manoeuvre start.
If the result of the test is negative (photocell blinded by the sun, wires short circuiting, etc.) the trouble is found and the
manoeuvre is not performed.
All this is only possible by using the connections given in Fig. 2B if two pairs of photocells are used (PHOTOCELL +
PHOTOCELL1), while if three (PHOTOCELL + PHOTOCELL II + PHOTOCELL1) or
(PHOTOCELL + PHOTOCELL II + PHOTOCELL1 + PHOTOCELL2) please refer to the diagram in Fig. 2C.
PHOTOCELL
PHOTOCELL 1
Fig. 2A
Fig. 2B
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PHOTOCELL
PHOTOCELL 1
When several photocells are installed near each other
they could interfere with one another.
To avoid such a problem, Nice has developed a
system called SYNCHRONISM that works on an
alternating current basis.
The accessories' output on the A824 unit is in direct
current which means that synchronised operation is
not possible. For this reason some specific outputs
have been prepared "Rx A , Rx B, Tx A and Tx B" on
which alternating current has been recreated, thus
rendering possible synchronism on Nice photocells.
To use this system connect the photocells as
indicated in Fig. 2B and cut the jamper of the TX.
PHOTOCELL II
PHOTOCELL 1
PHOTOCELL 2
Fig. 2C
four pairs of photocells are used
PHOTOCELL