Manual

3. Installation

PLM+ SERIES Operation Manual rev 1.0.0

3.3. Cooling

3.3.1. Overview

The PLM+ Series devices use a forced-air cooling system with airow from front to rear, allowing high continuous

power levels without thermal problems. Front-to-rear airow is preferable as air at the front of a rack is cooler than

that at the rear in nearly all situations; never attempt to reverse the airow. The operation of the PLM+’s cooling

system is dependent on front-to-rear airow; it will not function effectively with external airow in the opposite

direction.

Make sure an adequate air supply is provided in front of the PLM+, and that the rear of the PLM+ has sufcient

space to allow air to escape. If the PLM+ is rack-mounted, never operate the unit with any front or rear rack doors

or covers in position. It is recommended to keep the ambient temperature around the PLM+ as cool as possible.

An increased temperature can have a signicant negative impact on the expected lifetime on the components

inside the PLM+.

Note: Fit solid blanks (not ventilation blanks) to unused rack spaces to ensure effective air circulation.

Leaving gaps in between items of equipment degrades the effectiveness of forced-air cooling.

If installing one or more PLM+ Series devices in a rack with other fan-cooled equipment, be sure that all the

other equipment also uses front-to-rear airow for cooling. If this precaution is not observed, there is a risk of

overheating, as units with the reverse airow will be drawing in air which has already been heated by the PLM+s.

3.3.2. Temperature Sensing and Protection

The PLM+ is equipped with a sophisticated temperature sensing system which protects it from any overheating

which may occur as a result of inadequate ventilation.

Note: Always ensure the dust lters behind the detachable front panel are clean to ensure maximum

possible airow.

3.4. Operating Voltage

The label adjacent to the mains (AC) input connector indicates the AC mains voltage for which the device is wired

and approved. Both PLM+ models incorporate a universal power supply operating from 80 to 265 V. Only connect

the mains cable (AC cord) to an AC source of the voltage shown on the label.

The PLM+ uses primary switching, which means the mains power is rectied 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.