Smart Board Projectors

[moose]

Can anybody please help me as im one who does try to do the job correctly, but im unable to find the correct answers anywhere.

The issue is this, i have tested a number of Smart board Projectors and the readings are example of 4.

1 - 3.4mA
2 - 3.6mA
3 - 3.2mA
4 - 3.6mA

very close to the common 3.5mA, i would fail two of these projectors, but im thinking there is a get out clause maybe, like its about 5mA or upto max 10mA for projector or maybe rely on RCD protection been hard wired as well

number 2 is plugged in to a socket above the ceiling and 4 is hard wired to a Spur.

Could you direct me to some figures not say so please as gaffas need answers not jack said hehe.

Thanks guys for you time here..

 

[Pete999]

Daft question, but it is earth leakage you are talking about?

 

[moose]

Thats not a daft question as i didnt put it in m8 , but yes it is, the leakage is the problem i have.

 

[telectrix]

you can't fail them. all this type of equipmwnt has a small leakage. just like computers. that's why you should only wire a limited number to each RCD/RCBO.

 

[moose]

Well I can if I dont get the right answer to be honest, as testing the projector as an item comes in at 3.6mA which is a fail for an appliance, can you explain your answer better telectrix.

I know about Ring circuits and making clean earth to help etc. RCD ratio(mA stuff lol) for circuits but im looking how not to fail the projectors as an item doing PAT testing..

 

[dazza1981]

Tels point is you cant have to many items that have a leakage to earth i.e projectors and computers on 1 circuit as the accumulative leakage could take it over the 30 m/a threshold

 

[Pete999]

Well I can if I dont get the right answer to be honest, as testing the projector as an item comes in at 3.6mA which is a fail for an appliance, can you explain your answer better telectrix.

I know about Ring circuits and making clean earth to help etc. RCD ratio(mA stuff lol) for circuits but im looking how not to fail the projectors as an item doing PAT testing..

Have you read the BGB Reg 543.7.1.101? Have you tried using an earth leakage clamp meter on the equipment you are testing? your PA Tester may be giving you a duff reading

 

[moose]

The one item tested was a projector removed from the circuit and gave me a leakage of 3.6mA, using a PAT tester.

 

[dazza1981]

How old are these projectors???
Surely all 4 of them are not up the ****ter !!!
I know you said you would fail 2 of them but the others are pretty much the same.
I wouldnt mind betting if you tested them several times you would get different readings and the other 2 would possibly fail aswell.
Anyway pop a pass sticker on and go to sleep !!!:sifone:

 

[Pete999]

If it's over 3.5 ma and below 10ma then it should be on it's own circuit

 

[moose]

Thats the funny bit quite new thats why i was wondering if they have a designed leakage but was not sure, and if anyone had the same issue with the projectors, ive asked a few friends they get about 2.6mA for their readings from memory.

as for own circuit well ive never seen that so far from any ive seen nore been told by architect, while designing a class room etc.

Thanks for your great push questions and trys so far guys.

will get on tomorrow see if you solve my silly dillema.

 

[Pete999]

Thats the funny bit quite new thats why i was wondering if they have a designed leakage but was not sure, and if anyone had the same issue with the projectors, ive asked a few friends they get about 2.6mA for their readings from memory.

as for own circuit well ive never seen that so far from any ive seen nore been told by architect, while designing a class room etc.

Thanks for your great push questions and trys so far guys.

will get on tomorrow see if you solve my silly dillema.

May be they don't design the classrooms with Smart Boards as the main factor, the Regs do state the requirements as I have already posted

 

[davesparks]

It's all well and good quoting regs about how things should be installed, but it appears to be irrelevant to the question.

The OP has asked about appliance earth leakage when carrying out a portable appliance test.

 

[Pete999]

Can anybody please help me as im one who does try to do the job correctly, but im unable to find the correct answers anywhere.

The issue is this, i have tested a number of Smart board Projectors and the readings are example of 4.

1 - 3.4mA
2 - 3.6mA
3 - 3.2mA
4 - 3.6mA

very close to the common 3.5mA, i would fail two of these projectors, but im thinking there is a get out clause maybe, like its about 5mA or upto max 10mA for projector or maybe rely on RCD protection been hard wired as well

number 2 is plugged in to a socket above the ceiling and 4 is hard wired to a Spur.

Could you direct me to some figures not say so please as gaffas need answers not jack said hehe.

Thanks guys for you time here..

May be getting into trouble here, but why do you say 3.5ma is the cut off point for failure?

 

[Richard Burns]

May be getting into trouble here, but why do you say 3.5ma is the cut off point for failure?

According to the code of practice for class I equipment that is not heating (0.75mA/kW, max 5mA) or portable (0.75mA) then the maximum touch current should be 3.5mA or less.

 

[davesparks]

He's asking about leakage not touch current, unless I'm mistaken they are different.

 

[Richard Burns]

Since leakage to earth is not really covered in in service testing and he is using a PAT tester I would assume he is measuring the protective conductor current or touch current in accordance with the COP. which is the current that does leak to earthed parts.

In answer to the original question, there is not really any "get out clause". I would just say make sure you are testing correctly and see if you get different values, it is a bit of a pass fail situation for in service testing. But 3.5mA does seem a bit high for a smart board projector, they may be just a cheap power supply.

 

[davesparks]

I could have sworn our Portable appliance tester measured leakage current aswell as touch currents.

 

[moose]

Thanks for the great response to my main question, so the conclusion we all seem to agree is the projectors for the smart boards maybe, failing due to the readings given.

3.5 is a fail for class I equipment and no exceptions (not counting Heaters 3.5/5mA).

I like the idea of a bad power supply, this guides me to a reason, the tests where constant, as I tested 3 times and the readings did not change on three accounts.

Tester was a Martindale 2100.

Thanks again for the good advice..