RCD UPSIDE DOWN ?

If the RCD is marked “top” or “bottom” then it should in view be installed as directed. Otherwise I doubt that it matters. The up versus down convention for off has altered over the years.

The general standard for this is BS EN 60447 Basic and safety principles for man-machine interface, marking and identification — Actuating principles. According to this standard, the direction “UP” means “start machine” or “close electrical circuit”, and “DOWN” means “stop machine" or “open electrical circuit” (Normative Annex A, Tables A.1 and A.2) 

Note, however, that it is a basic safety standard for use by standards committees, and is probably more aligned with considerations for machinery, and where an innate haptic meaning may be more appropriate.

In general, there is no convention specifically mandated in standards for electrical protective devices and isolators, because it is recognised that devices may be installed in different orientations if this is not precluded by the manufacturer. For example, product standards for these kinds devices have the following requirements:

• BS EN 60898, BS EN 61008 and BS EN 61009 simply require the open position and closed positions to be clearly indicated by ‘O' and ‘I’ respectively. Of course this is not required for mcb's, RCDs or RCBO's that use a push-button “set/reset” type arrangement.
   
• BS EN 60947-1 says that whilst generally the operation of actuators should conform to IEC 60447 (BS EN 60447), where devices may be used in special applications or alternative mounting positions they should be clearly marked such there is no doubt as to the ‘I’ and ‘O’ positions, and the direction of operation.

We certainly ignore BS EN 60447 with general-purpose light switches and many “domestic” controls. One suggestion I've heard offered for this is perhaps  it's easier to “fumble” a light switch switch into the “on” position in the dark, if “down” is “on”.

All consumer units etc were downside up until a few years back. the changeover in convention tricked a few. Even now you find some installations that contain consumer units with both conventions

These conventions change, sometimes for good reasons.

Railway signals used to be horizontal for stop and down for go until some linkage failed and a signal dropped when it should have been up. Net result catastrophe and the new convention became up for go with fail-safe rather than fail-danger.

Light switches can of course be mounted either way and in some other countries (e.g. USA) it is up for on and down for off.

Two (or more) way switching breaks the mould.

But AFAIK, switched sockets (which are not ordinarily found elsewhere) have always been up for off and down for on.

RCD terminals are more likely to be marked in and out than top and bottom. 

Railway signals used to be horizontal for stop and down for go until some linkage failed and a signal dropped when it should have been up. 

Nah, both lower quadrant (down for go) and upper quadrant (up for go) semaphore signals fail safe (i.e. to horizontal stop/red/danger) when a cable snaps (they have weights on the arm itself to ensure that). The difference was more regional - the old Western region (and a few other places) stuck with lower quadrant until replaced with fangled electric light ones.

  - Andy.

 The Gas Safety (Installation and Use) Regulations 1998 (legislation.gov.uk) are specific for emergency control valve handles, down for off, its the Law ;)

Emergency controls

9.—(1) No person shall for the first time enable gas to be supplied for use in any premises unless there is provided an appropriately sited emergency control to which there is adequate access.

(2) Any person installing an emergency control shall ensure that—

(a)any key, lever or hand-wheel of the control is securely attached to the operating spindle of the control;

(b)any such key or lever is attached so that—

(i)the key or lever is parallel to the axis of the pipe in which the control is installed when the control is in the open position; and

(ii)where the key or lever is not attached so as to move only horizontally, gas cannot pass beyond the control when the key or lever has been moved as far as possible downwards;

…

If “O” = Off, and “1" = On, it doesn't really matter which way the R.C.D is positioned, except if its ability to function correctly is affected.

Block signalling seems to be a good idea.

Z.

AJJewsbury: 
Nah, both lower quadrant (down for go) and upper quadrant (up for go) semaphore signals fail safe (i.e. to horizontal stop/red/danger) when a cable snaps (they have weights on the arm itself to ensure that). The difference was more regional - the old Western region (and a few other places) stuck with lower quadrant until replaced with fangled electric light ones.

Yes, well, there is more than one way to skin a cat. The fact remains that some way had to be found to make signals fail safe.

garywwess: 
 

Hi All,  hmm,  i have a shiny box with a plug on it..  so far so good ..except the RCD is mounted upside down, i would have thought that generically speaking ALL switches for isolation or reset would have been “lift to reset” & trip down for off but cant find anything that backs this up.. but, the wording is also upside down on this one and on another where the wording is correctly oriented it clearly states up for ON when it is obviously the other way round (proved live).. 

any reference material you can point me too..

gary

Hi Gary, on the second one, does it say up for "on" on the enclosure or on the RCD? What is this enclosure with a plug on it? Pics would be nice.