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How to apply applicable standards.

Mike Mln

Hi all,

I have a bit of an issue on how to correctly apply some standards.

The job has some heat pumps in a room acting as the secondary side of a heating loop. The standard BS EN 378 Refrigerating systems and heat pumps — Safety and environmental requirements, is what was put to me as a standard to try and meet. Which I have no problem with, reading through, all seems quite reasonable.

When I get to 378-3, section 5.6, it talks about a remote emergency switch, which needs to be outside the room that stops the refrigerating system, it also needs to meet the requirements of emergency switches of EN ISO 13850 and EN 60204-1.

Normally this would be fine, but the only exit to the room that holds the equipment is onto a public access area. 

So that opens it up to a lot of nuisance stops. 

How do people balance following the given standards against use of the system, when a part of the standard can seemingly inhibit the systems usefulness.

This is especially odd in this case as the stop would not serve to avert or reduce hazards to people or damage to machinery, which is what the emergency function is intended for.

The standard doesnt seem to allow for it to be risked assessed out.

I can stand to learn a lot more about standards and how to apply them, but how does everyone else manage when they come across the edge case that would make applying the standard less effective.

Mike.

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  • 0
    Mike Mln said:
    This is especially odd in this case as the stop would not serve to avert or reduce hazards to people or damage to machinery, which is what the emergency function is intended for.

    I'm no expert in such things, but I can imagine that a faulty cooler could catch fire and leak refrigerant averywhere.  I wouldn't want to be the person who has to go into that room to hit the emergency stop button.

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  • 0
    Mike Mln said:
    This is especially odd in this case as the stop would not serve to avert or reduce hazards to people or damage to machinery, which is what the emergency function is intended for.

    I'm no expert in such things, but I can imagine that a faulty cooler could catch fire and leak refrigerant averywhere.  I wouldn't want to be the person who has to go into that room to hit the emergency stop button.

Children
  • 0 in reply to Simon Barker

    Hi Simon,

    I would say that a fire is not an situation where an emergency stop would be effective as by pressing it wouldn't stop the fire (the main hazard in that case). The emergency stop function in the standard suggested reads more like averting hazards by stopping movement based devices (reads like it is intended or based on conveyor systems).

    The reason I think it is ok to omit in this case, is it is an unoccupied room with no through ways, so the only reason to be in there is maintenance of equipment. When maintenance is being done the management system would turn off the system function, then parts that need maintaining would be isolated as required.

    The refrigerant is contained inside of the heat pump enclosure, so if it leaks it isnt spraying across a whole room, it is into its enclosure. If it does leak an emergency stop wont stop it from leaking. The only other risks are from the characteristics of the refrigerant itself, but in this case, it is low toxicity and low flammability and the size of the discharge is low enough to not displace enough O2 to be considered hazardous.

    The heat pump itself also has measures built into its design, to reduce risk.

    I am not against having emergency switches available for the system itself, it is just the one instance where it would be placed in public access, the standard for emergency switches also says to not place in areas where it can be activated unintentionally.

    The standard also calls for another switch just inside the room, which I have no issues with.

    Mike

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