Checking the ground fault surveillance function

Checking the ground fault surveillance function:

When the NRS 90224 is installed and the power amplifier is switched on, the green READY indicator (7) has to light. Utilizing an external switch to connect one pole of the 100V-loudspeaker network via a 47 k ohms resistor for approximately 5 seconds to ground potential, the corresponding red GROUND FAULT indicator (6) has to light and the READY fault message relay of the INPUT MODULE NRS 90225 drops while the green READY indicator (7) stays lit. After releasing the button, the indication and the fault message are maintained. The TEST button (3) has to be used to reset the ground fault surveillance function. For further details on checking the function with the REMOTE MODULE NRS 90222 being included in your installation, please refer to the PROMATRIX handbook.

9.19"-case and 19“-rack-shelf system installation

Note	Operation of the power amplifiers DPA 4120 and DPA 4140 with enclosure cover plates detached is
	strictly prohibited.

When mounting the power amplifiers within rack-cases or rack-shelf systems make sure to provide sufficient airflow. The space between the rear panel of the amplifier and the inner wall of the rack-case has to be at least 60 mm x 330

mm.A free space of at least 100 mm above the rack-shelf system is needed to provide sufficient air circulation. Since it is possible that during operation the temperature inside the rack system increases by 10° C, the maximum allowable ambient temperatures of the rest of the incorporated modules and appliances within a specific rack-shelf or rack-case have to be taken into careful consideration.

Note	To ensure trouble-free operation of the appliance, the maximum permissible ambient temperature of
	+40°C is not to be exceeded.

10.Ground lift switch CIRCUIT ⊥ TO CHASSIS SWITCH

The ground lift switch CIRCUIT ⊥ TO CHASSIS SWITCH (19) provides the possibility to separate the signal ground from the enclosure (ground potential). This is mainly meant to eliminate noise-problems which are introduced through ground-loops, without jeopardizing the security. In case several appliances within a single rack-case or rack-shelf are furnished with ground lift switches, it is recommended to set all devices but one to "ungrounded“. Set one appliance to "grounded". When set to "ungrounded", the impedance between signal ground and enclosure is : 100 k ohms // 100 nF. It is needed to maintain EMV protection.

11.Fuses

11.1 Fuses in the DPA 4120

location	Pos.	purpose	value	dimensions	standard
fuse socket (11)	F601	mains fuse 230V~ AC	T2A	5x20 mm	IEC 127-2-3
fuse socket (11)	F601	mains fuse 115V~ AC	T4A	5x20 mm	IEC 127-2-3
printed board assembly	F602	mains fuse 100V - 250V	T1A	Ø 8.5xRM 5.08mm	IEC 127-3/4
86243
printed board assembly	F502	battery fuse 24V DC	15A	flat fuse	DIN 72581-3
85270
printed board assembly	F503	battery fuse 24V DC	15A	flat fuse	DIN 72581-3
85270
11.2 Fuses in the DPA 4140
location	Pos.	purpose	value	dimensions	standard
fuse socket (11)	F601	mains fuse 230V~ AC	T4A	5x20 mm	IEC 127-2-3
fuse socket (11)	F601	mains fuse 115V~ AC	T8A	5x20 mm	IEC 127-2-3
printed board assembly	F602	mains fuse 100V - 250V	T1A	Ø 8.5xRM 5.08mm	IEC 127-3/4
86243
printed board assembly	F502	battery fuse 24V DC	25A	flat fuse	DIN 72581-3
85268
printed board assembly	F503	battery fuse 24V DC	25A	flat fuse	DIN 72581-3
85268

DPA 4120, DPA 4140 specifications

The Dynacord DPA 4120 and DPA 4140 are powerful amplifier solutions designed for professional audio applications. These models are ideal for live sound reinforcement, permanent installations, and various audio distribution requirements.

Both DPA 4120 and DPA 4140 are part of the Dynacord DPA series, which is renowned for delivering high-quality sound and reliability in demanding environments. The DPA 4120 provides a robust 1200 watts of power per channel at 4 ohms, while the DPA 4140 ups the ante with an impressive 1400 watts per channel at the same impedance, making them suitable for driving a wide range of speaker systems.

One of the standout features of both amplifiers is the incorporation of advanced DSP (Digital Signal Processing) technology. This technology offers precise control over sound performance, allowing users to tailor settings to meet specific venue acoustics or personal preferences. The DSP includes functions such as equalization, crossover adjustments, delay, and limiting, ensuring optimal sound delivery in any setting.

Durability is another hallmark of the Dynacord DPA series. The amplifiers feature a rugged, lightweight design, ideally suited for touring and rental companies. The internal architecture includes a sophisticated cooling system that allows for extended operation under high-demand conditions without overheating.

Both models are equipped with a range of connectivity options, including XLR inputs and Speakon outputs, facilitating seamless integration with various audio systems. The amplifiers support both analog and digital input sources, ensuring compatibility with modern audio setups.

In terms of sound quality, the DPA 4120 and DPA 4140 are engineered with low distortion levels and high efficiency, achieving high-performance audio output while maintaining clarity and detail across all frequencies. The amplifiers also feature a robust power supply that delivers consistent performance, even during peak use scenarios.

User-friendly controls and monitoring options are also inherent in the design of these amplifiers. An intuitive front panel interface allows for easy adjustment of settings, while LED indicators provide real-time feedback on performance and operational status.

In summary, the Dynacord DPA 4120 and DPA 4140 offer exceptional power, sound quality, and advanced features, making them excellent choices for audio professionals seeking reliable and powerful amplification solutions. Their combination of performance, durability, and versatility serves to meet the needs of various professional audio applications, solidifying their place in the competitive landscape of audio amplifiers.