Grounding - Lab.gruppen PLM series Operation Manual

5. Installation
The PLM uses primary switching, which means the mains power is rectified on the primary side of the
transformer. This makes the power supply insensitive to mains frequency variation, and it will operate
normally on line frequencies from 45 to 75 Hz.
If the mains plug (AC plug) fitted to the mains cable (AC cord) is not appropriate for your country, it can be
removed and a locally-sourced one fitted instead, observing the color coding in the table below:
PowerCon Pin
L
N
Table 5.5: AC plug configuration
If you are not 100% confident of your competence to replace the mains plug (AC plug), the task should
be carried out by qualified personnel.
Once a suitable AC supply is connected, the PLM can be turned on using the front panel power switch.
When the unit is switched on, the PLM goes through a soft-start sequence as it performs a diagnostic
routine on the internal circuitry. The fans will run at high speed for a short period before dropping to idle
speed, and the power symbol in the power switch will change from red (Standby mode) to green (active).
In-rush current is controlled and limited during the
soft-start sequence, enabling multiple PLMs on the
same AC mains circuit to be powered up simultane-
ously.

5.6 Grounding

Analog inputs feature Iso-Float
coupled isolation with the advantages of clean, direct-coupled inputs.
The audio converters are galvanically isolated, and not connected to the main ground. High-speed transform-
ers and opto-isolators create a barrier between the PLM and the outside electrical environment.
The Iso-Float feature is activated by default, but
may be disabled via the supplied Lake Controller
software, or via the PLM's front panel menu system.
In the interests of safety, NEVER disconnect the earth (ground) pin on the mains cable (AC power cord).
Use correctly-shielded balanced audio input connections to minimise hum and interference. Refer to section
10.2.1 for more information.
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PLM Series Operation Manual rev 1.1.3
230 V Version 115 V Version
Brown Black
Blue White
Green/Yellow Green
ground isolation, a technology which combines the benefits of transformer-
™