HP Cut OUt device

[Peter_1]

What are the European regulations for installing a HP cut-out on a small hermetic compressor (1 HP) with max 2,3 kg refrigerant in the system?
Is it obligated to install one and what does the regulation say about the manual or automatic reset?

[Argus]

Peter,

There are more than two questions here.....

I presume that you are concerned with a typical small split system, the type that are mass produced and intended for the domestic A/C market or small commercial cabinet systems?

The main two legislative instruments that come to mind are both CE marking issue, therefore part of the new approach legislation in the EU:

1. Low Voltage Directive. (LVD)
2. Pressure Equipment Directive (PED)

However there?s more to it than that.

The LVD deals with mechanical hazard and can also satisfy the Essential Safety Requirements of the Machinery Safety Directive where the hazards are mainly electrical in nature.

The PED deals with equipment that is demonstrated as over Category 1 in the Schedules.
It is probable that a unit of the type that you describe would be below Category 1 of the PED, so not included.

However the PED is served by EN 378 that is harmonised to the directive. Have a look at Part 2, Para 7.4.2.4:

The steady state condition they describe is one where it is assumed that all the fans are inoperative and the developed pressure is lower than the maximum allowable pressure ? rather like a domestic fridge.

There is an international standard (not applicable in Europe, but was widely used elsewhere in the world) , ISO 5149 that describes an ?Intrinsic Pressure test? where all the fans are disconnected and the system subjected to the pressure developed at the design ambient condition. (I?m not certain that this standard is still current, though). This is most applicable to small split air con and window wall types - these are never fitted with HP switches.

As far as the second part is concerned, it is not obligatory for equipment outside the scope of the PED as far as I can see from the current standards, it depends on the type of system. Many of us who work on larger equipment tend to expect them.

Hope this helps ? come back to me if you need some more info, it's a surprisingly complex area of conformity.


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