rcf SB 3320 Instrucciones De Uso página 10

NOTE
• In a system with multiple SB 3320 boards on which the FIRE-BREAK function is enabled by a single command, enabling
alarm transmission only on the first and last board of the chain makes it is possible to control correct functioning of the con-
nection between the first and last devices; this also prevents having to silence the alarm on all the boards where the FIRE-
BREAK has been enabled.
DETECTOR GAIN INCREASE
The JP2 jumper on the SB 3320 board is used for increasing the gain of the fault detector circuit by 6 dB. This increase must
be set when the board is being calibrated for using the LINE FAULT and PA FAULT functions and the DL2 LED does not light
up. This could be due, for example, to a total load having a very high impedance (few loudspeakers connected to the line).
POSITION OF "JP2" JUMPER
Short circuit of terminals 1 – 2
Short circuit of terminals 2 - 3
DISABLING THE "LINE FAULT" AND "PA FAULT" FUNCTIONS
Jumpers JP3 (ref. 16 - Fig. 1, page 32) and JP4 (ref. 15 - Fig. 1, page 32) on the SB 3320 board make it possible to disable the
LINE FAULT and PA FAULT functions. Disabling the LINE FAULT function is indispensable when the SB 3320 board is
coupled with an RB 3300 board that controls a backup amplifier, and prevents involuntary activation of the respective
alarm. Each jumper can short-circuit two terminals on the board.
CALIBRATING THE BOARD
Once the board has been correctly installed, it must be calibrated. The calibration differs depending on whether or not the
LINE FAULT function is used. Calibration makes it possible to regulate the test tone which is applied to the amplifier being
controlled and enables the board to detect the respective faults.
CALIBRATION FOR USING THE "LINE FAULT" AND "PA FAULT" FUNCTIONS
The procedure described below is used for calibrating the board in order to use both the LINE FAULT function and the PA
FAULT function. With this calibration, you can regulate the level of the test tone according to the nominal load connected to
the board, which depends on the number of speakers connected, the electrical characteristics of the speakers, the length of
the line, and the type of connections made.
1) Make sure that the LINE FAULT and PA FAULT functions are enabled (see the section DISABLING THE LINE-FAULT AND
PA-FAULT FUNCTIONS).
2) Connect the speakers to the board as described in the section CONNECTIONS, and check to make sure they are operating
correctly.
3) Switch on the amplifier and make sure that the volume control is in a position of normal use.
4) Observe the LEDs DL1, DL2 and DL3, and turn the trimmer RV1 (rif.9 – fig.1, page32) until only LED DL2 lights up (line in
normal conditions).
5) Then turn trimmer RV2 (rif.17 – fig.1, page32) until you find the point in which LED DL2 is on and LED DL1 has just gone
off.
NOTE
• If LED DL1 does not go off, re-check the speaker line, as there is a short circuit.
• If LED DL3 does not go off, try increasing the gain of the circuit that detects board faults, as described in the section
INCREASING THE DETECTOR GAIN. If LED DL3 still does not go off, re-check the speaker line, as the electrical continuity
is interrupted (line open).
5) If necessary repeat the adjustment operations of the trimmers RV1 and RV2 to further refine the calibration, where LED DL2
must be on it stable mode and the limit prior to switch-on od LEDs DL1 and DL3.
NOTE
• Once the board has been calibrated, during normal system operation there may be certain conditions (e.g. background
music transmission) that cause the DL1 and/or DL3 LEDs to light up intermittently. In general, this does not create any prob-
lems, as the LINE FAULT and PA FAULT alarms are activated and transmitted to the CP3100 control unit only when the
alarm conditions persist continuously for at least ten seconds
(standard position)
JUMPER "JP3"
Terminals open
Terminals short-circuited
JUMPER "JP4"
Terminals open
Terminals short-circuited
FUNCTION
Normal gain
Gain increased by 6 dB
FUNCTION
PA FAULT function enabled.
PA FAULT function disabled.
FUNCTION
LINE FAULT function enabled.
LINE FAULT function disabled.
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