Dynacord DPA 4140, DPA 4120 owner manual 3.2Battery operation 24V DC, Input

If the appliance is correctly connected and mains is present the green STANDBY indicator (4) will light. To remotely start the amplifier when it is being operated on the mains, it is necessary to interconnect the contacts 3 - POWER REMOTE and 2 - GROUND STANDBY on the pin terminal strip REMOTE CONTROL (16) (see also paragraph 5.6).

The main power switch POWER (9) on the rear of the appliance is meant for service and maintenance purposes. This allows bridging the mains switching relay, which provides the possibility to operate the amplifier without remote start.

Note	The main power switch POWER (9) on the appliance's rear is only meant for maintenance.
	Remotely switching off the device is not possible when the POWER switch is engaged.

Both amplifiers, the DPA 4120 and the DPA 4140, employ power-on switching delays of approximately 3 sec. After this time, the green READY indicator lights and the READY fault message relay picks up when no error is being detected (see also paragraph 6.2).

3.2Battery operation 24V DC

The amplifiers, DPA 4120 and DPA 4140, use the mains or alternatively an external 24V battery as power source. Switching to battery is performed via integrated relays.

The battery has to be connected on the rear of the amplifiers (20) using insulated 6.3x0.8 mm AMP flat plug connectors. The amplifiers are protected against polarity-mismatch. Each, the positive and negative conductors are internally protected by fuses, located on the printed board assembly 85270 (DPA 4120) respectively 85268 (DPA 4140) (see also paragraph 11, figure 10 and 11).

The cable used for battery connection has to be at least 1.5 mm2 in diameter (DPA 4120) respectively 2.5 mm2 (DPA 4140). Using these diameters, the cable length for the one way distance should not exceed 4.0 m (max. voltage drop <1V).

Caution The DPA 4120 and DPA 4140 are to be operated only using ungrounded batteries or batteries with grounded negative pole. Operation with grounded positive pole is not permissible.

4.INPUT

The electronically balanced INPUT (14) providing a sensitivity of 775mV = 0dBu is meant for the connection of control amplifiers. In case it is intended to supply several power amplifiers with identical input signals, these signals can be taken from the THRU connector (15) (see also figure 1 and 2).

The input is prepared to be retrofitted with a input transformer. In case a floating input is needed, it is necessary to install the optional extension NRS 90208 (see also paragraph 8.3).

On the general input module NRS 90225 the input level is set with the level control (13). For the remote control module NRS 90222 the input level is determined by the setting of the internal electronic level control of the PROMATRIX manager DPM 4000 (please also refer to the PROMATRIX handbook).

figure 1 connections of the input sockets

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