mark.g
I concur with Grizzly over this.
Also a small portable power supply such as a phone charger is unlikely to be a voltage divider, the transformer rectifier solution is more likely, it may also be a switched mode power supply these days.
Also note that they are not a safety isolated device, there is the possibility under certain failure modes for the input voltage to appear at the output terminals.
That is they are NOT, SELV, or PELV devices.
They should be tested.
IF that is the procedure that you wish to implement.
Remembering that the IET CoP gives further guidance, as do various HSE and ESC guidance as has already been suggested.
redken,
Please see my comments below,
All,
Be very careful however, to take Grizzly's basically correct statement including large hard wired items for granted. Items such as wall heaters, built in appliances, large stationary appliances such as fridges, can be considered under a PAT regime quite easily. However, to undertake a full test on a wall mounted electric heater will necessitate dismantling and disconnection of aspects of the fixed wiring installation those undertaking such disconnections and reconnections should be competent to do so. A PAT course would not give you this level of competence. Safe isolation would be required as live working in this scenario would not be excusable.
All the PAT in the world will not protect you if there are defects in the fixed wiring installation. If the portable appliance relies on the “earth” conductor in the fixed installation for its protective measures, if this is not present or inadequate then there is still a serious hazard even if the appliance has just passed its PAT and has developed an internal fault just after, or if the fixed heater disconnected and reconnected by the PAT person did not have its circuit protective conductor (earth) correctly reinstated after test.
One must be careful of machinery built to BS EN 60204-1 standards, basically the machine equivalent of BS7671 (IEE Wiring regs).
Applying the IET CoP to such equipment by unqualified personnel leaves a lot to desired, believe me I have seen it many times! Inspection and testing on large fixed machinery such as machine tools etc. is best left to professionals, PAT companies should be extensively interrogated in their competence to undertake any such work.
rnighting,
Whilst I see and understand your points, I fail to see the place for flash testing at 1k5V or 3kV during in service inspection and testing.
This is specifically excluded as a requirement in the current IET CoP for in service I&T.
Many PAT machines for several years now have had a low current earth bond test (around 100mA) which can be utilised to confirm the continuity of the earth bond, whilst minimising the current flow through the “appliance” which also could cause damage to equipment, remembering that a “normal” earth bond test provides up to around 25A for up to around 20s.
As I understand the engineering behind this, as I have studied it, it is to highlight any possible high resistance or otherwise weak junctions in the earthing of the appliance.
This is similar to the high current test that can be applied to metallic wiring containment systems such as conduit and trunking to confirm their earthing integrity is it not?
Paul.