Computer PAT Testing Question

[disinfo]

When a computer is PAT tested, should it fail (on visual inspection) because a floppy / CD drive bezel is missing allowing access to the ELV components?

 

[plugwash]

I'm not a pat test expert but it seems strange to fail it on those grounds when the majority of computers have external ports with touchable pins on anway.

 

[disinfo]

Yes, I was thinking the same. Would like to have a look in the IEE code of practice to see if this issue is mentioned.

Anyone know for definite?

 

[ericmark]

If one was to test a computer to the letter of the regulations most would fail because the

Isolation sign

• ericmark
• 12 Mar 2009
• 10

sign is often covered up during the build. One has to use some common sense and if only SELV items can be touched then one would normally pass it even where it does not strictly speaking comply.

 

[disinfo]

What does the symbol mean please ericmark?

 

[timtheenchanter]

I would pass it, if we were going strictly by regs, then it would fail with or without the bezel because it doesnt require a tool to remove it.

 

[Grizzly]

What does the symbol mean please ericmark?

It's the symbol for a safety isolating transformer, one that would be used to supply SELV to Class III equipment.

Eric is a bit off-base on this one, as the power supply in most PCs would not be a safety isolating transformer, as the earth connection is carried over to the ELV side of things, so one would be hunting fruitlessly for the above symbol most of the time.

 

[JohnD]

memory a bit ropey here...

doen't SELV have to have no earth connections, but ELV can?

 

[Spark123]

SELV is Separated Extra Low Voltage - it has no connection with earth.
PELV is Protective Extra Low Voltage - this is similar in most respects to SELV but the supply is tied to earth.
FELV is Functional Extra Low Voltage - this doesn't necessarily isolate the supply from the mains.

 

[ericmark]

What does the symbol mean please ericmark?

It means the transformer isolates and so the output does not need an earth. i.e. complying with BS EN 61558-1 and BS EN 61558-2-23

See 559.11.3.1 although that is to do with lighting all isolation transformers should be marked with it. Some do have other equivalent markings but often you find because of the way the power supply mounts in the case of the PC the markings on the power supply are obscured. Sometimes a spare label comes with power supply which should be fixed to computer case but often these are not stuck on.

Of course not sticking on a label does not make it dangerous but it does make in non compliant.

I have had the same with the

sign where you know it is double insulated but the sign is missing. And with grinders the speed has been rubbed off with use. One has to consider how pedantic the safety officer is and decide if you pass or not.

 

[kkynaston]

I have quite a few machines with bezels missing at work (slowly being replaced ) and 1 tester passed them, the other needed persuading.

He said that the user could touch exposed live parts and I argued otherwise

 

[Steve]

He said that the user could touch exposed live parts and I argued otherwise

I can imagine you now, fumbling around inside the case through a cd drive shaped hole

"look, im not dead!"

 

[seasickstevie]

... then it would fail with or without the bezel because it doesnt require a tool to remove it.

That would surely apply also to all CUs with plastic MCB replacement push-on blanks.

(Sorry if I'm going off on a tangent here)

 

[disinfo]

That would surely apply also to all CUs with plastic MCB replacement push-on blanks.

(Sorry if I'm going off on a tangent here)

Is a CU a portable appliance?

 

[seasickstevie]

Good point.

Like I said - going off tangent.