UL 60079-6-2016 pdf download
UL 60079-6-2016 pdf download.Explosive atmospheres – Part 6: Equipment protection by liquid immersion “o”.
3.5 maximum permissible protective liquid level maximum level that the protective liquid can attain in normal service, taking into account the effects of expansion from the worst-case filling condition specified by the manufacturer to the condition of full load at maximum ambient temperature for which the equipment is designed
3.6 minimum permissible protective liquid level minimum level that the protective liquid can attain in normal service taking into account the effects of contraction from the worst-case filling condition to the condition of de-energization at minimum ambient temperature
3.7 disconnector mechanical switching device which provides, in the open position, an isolating distance in accordance with specified requirements
Note I to entry: A deawineclor 15 capable of opening and closing a cuit when either negligible current is broken or made, or when no signircanl change in the voltag, across the terminals of eadi of the poles or me disociviector ocøs. It is also capable of carrying currents under normal circiet conditions and carrying for a specritied tinie Nrenf a under abnormal conditions audi as those of short circuit.
[SOURCE: IEC 60050-441:1984, 441-14-05]
3.8 switchIng device device designed to make or break the current in one or more electric circuits
[SOURCE: IEC 60050-441:1984, 441-14-011
3.9 safety device dev’ce intended for use inside or outside explosive atmospheres but required for or contributing to the safe functioning 01 equipment and protective systems with respect to the risks of explosion
3.10 tap selector device designed to carry, but not to make or break current, used in conjunction with a diverter switch to select tapping connections
[SOURCE: IEC 60050-421 :1990, 421-11-021
4 ConstructIonal requirements
4.1 General
For Type of Protection liquid immersion o, the Ex Equipment or parts of the Ex Equipment are immersed in a protective liquid in such a way that an explosive gas atmosphere, which may be above the liquid or outside the enclosure, cannot be ignited.
The Ex Equipment is constructed to ensure that the necessary amount of protective liquid is present. Dependent on the intended Equipment Protection Level, this is achieved by monitoring device(s), indicator(s) or a level control safety device with automatic switch off.
4.1 DVI DR Modification of Clause 4.1 NOTE to replace with the following:
NOTE In accordance with the requirements for all electrIcal equipment gIven in UL 60079-0 lEG 600704, It Is assumed that the relevant Industrial requIrements have been applIed. The requirements of the UL 60079-0 and Its sub-orts lEG 60079 eerie. ot standards supplement those industrial requirements.
4.2 Levels of protection and requirements of electrical equipment
4.2.1 Level of Protection
Electrical equipment with liquid immersion o” shall be either:
a) Level of Protection “ob’ (EPL Gb or Mb): or
b) Level of Protection “ac’ (EPL Gc).
The requirements of this standard shall apply to all levels of protection unless otherwise stated.
4.2.2 Requirements for Level of Protection “ob”
Electrical Circuits and components, when liquid immersed in accordance with this standard, are considered to be not ignition capable in normal operation and during expected malfunctions, and shall be assigned a Level of Protection ob” (EPL Gb 01 Mb).
A liquid level indication according to 4.7 is required.
Switching devices protected by liquid immersion level of protection ob” shall comply with the following additional requirements:
a) When a sealed enclosure is employed, the enclosure shall comply with the overpressure test in 6.1.1 using four times the prescribed pressure.
b) Electrical equipment containing switching devices operaled In the protective liquid, rated at 2 KVA per contact or less, are permitted without further test. Where the switching device is rated above 2 kVA per contact, neither pressure increases nor excessive decomposition products shall invalidate the type of protection as demonstrated by tests In accordance with 6.1.5.
c) The equipment shall be suitable for a prospective short circuit current of 32 kA unless marked with a lower value.
