B8Test procedure#

B8.1General#

B8.1.1Temperature Sensors#

Temperature sensors shall have response times that are short in comparison to the thermal variations of the environment they measure.

The temperature sensors used in the test procedure shall be in accordance with Clause 5.2, Category 2, of AS 2853 (Withdrawn).

B8.1.2Test Sites#

A test Site is a location at which a temperature sensor is positioned for the purpose of temperature measurement. There are 2 types of test Sites, namely, Standard Sites and Supplementary Sites. The selection of these Sites for any type of enclosure shall be in accordance with Clause 5.3 of AS 2853 (Withdrawn). Unless specified otherwise, the calculation of the number of standard tests Sites (N) in accordance with AS 2853 (Withdrawn) shall utilise a cabinet grade (G) of 1 and 3 for standard and extended cabinets respectively.

B8.2Default internal load of enclosure#

ITS and Electrical enclosures are intended for housing equipment with varying heat emitting characteristics. The distribution of the heat load in an enclosure shall be as close as possible to the distribution of the load in the intended application. Unless otherwise specified, the default load of telecommunications field cabinets shall be 500 W, distributed as follows:

  1. a)250 W for the top section (the top third of the cabinet)
  2. b)125 W for the middle section (the middle third of the cabinet), and
  3. c)125 W for the bottom section (the bottom third of the cabinet).

The top, middle and bottom sections shall be evenly allocated for the entire height of the cabinet.

B8.3Steady-state thermal performance testing#

Steady State Thermal Performance Testing is used to confirm the cabinet will perform with maximum thermal loading. The general requirements and procedures for the test are as follows:

B8.3.1General requirement#

  • Relative humidity shall be set to 80 ± 3% for standard enclosures, and 60 ± 3% for extended enclosures in accordance to AS 60068.2.78, and
  • Ambient temperature simulation shall be in accordance with AS 6068.2.2 Test Bd.

B8.3.2Procedure#

The ambient temperature in the test chamber shall be maintained at the specified value ± 5% for at least 4 hours in accordance with Clause 7.2. The internal enclosure temperature (TI) shall be stable for the final 2 hours of the test.

B8.4Data acquisition#

Before each test commences, the following checks shall be completed:

  • The correct allocation of the heat load
  • The activation of the temperature control system including the thermostat and fans, and
  • The correct placement of the internal and external temperature sensors.

Data from each temperature sensor shall be captured at intervals of 30 seconds, for the duration of each of the tests.

Source: MRTS201 · pages 56–57 Open PDF at this page Search this document