Lab.gruppen C Series 88:4 - Manual (Page 13)

3. Installation
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C Series C 88:4, C 68:4, C 48:4, C 28:4 and C 16:4 Operation Manual rev 2.2.3
3.4 Operating voltage
The label placed to the right of the mains cable on the rear of the amplifier indicates the AC mains
voltage for which the amplifier is wired and approved: 115 V or 230 V. Connect the power cable only to
the AC source type referred to on the label. The warranty will not cover damage caused by connecting
to an incorrect type of AC mains.
Lab.gruppen switch-mode amplifiers use primary switching. Because the mains power is rectified directly in
front of the transformer, the amplifier is insensitive to mains frequency. It may be connected to 50 or 60 Hz
sources, and actually will operate on line frequencies from DC to 400 Hz.
If the power plug mounted at the factory is not appropriate for your country, it can be removed and the proper
connector wired in its place as follows:
BLACK or BROWN LIVE
WHITE or BLUE NEUTRAL
GREEN or GREEN/YELLOW EARTH (GROUND)
If you are not 100% confident of your competence to replace the mains plug, engage qualified personnel
to do the job.
Once a suitable AC supply is connected, the amplifier can be turned on using the front-panel power switch.
The amplifier then goes through a soft-start sequence as it self-checks its circuits. The fans will blow at high
speed before dropping to idle, and the “power” LED will illuminate.
Inrush power is controlled and limited during “soft start”, enabling multiple amplifiers to be powered up simulta-
neously.
3.5 Grounding
There is no ground lift switch or terminal on the C Series amplifiers. The signal ground is always floating, via a
resistor, to chassis and therefore the grounding system is automatic.
In the interests of safety, never disconnect the earth (ground) pin on the AC power cord.
Use balanced input connections to avoid hum and interference.