Discuss Electric knife: strange wiring: request advice in the PAT Testing Forum area at ElectriciansForums.net

mark641

EF Member
Messages
7
Location
egham
The knife is Russell-Hobbs, ECO1255, model 13892.
I work for a charity which receives (among other
things) electrical goods
which must be tested before we can give them to
recipients. The PAT meter gave weird results: normally
when the device being tested is switched off the meter
says "lo load", but on this knife it did not
do so. I tested further:
when the knife is off, the resistance between live &
neutral is ~~ 1/2 Megohm. So if you leave it plugged
in & switched off, it will
draw a continual leak current 1/2 ma. (that is an
estimate: I dont have a
meter to measure this). So I opened it up &
the supply wires go
into a PCB which I assume is for radio interference
suppression. And this PCB is upstream of the switch.

Please: is the knife supposed to be made this way
or is it defective?
Am I right in my belief that this violates
the Regulations?

thank you RM Damerell
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,342
Location
cheshire/staffordshire
think you'll find it's perfectly OK. some appliances will give low readings due to the RF suppression.
 
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ackbarthestar

Forum Mentor
Messages
2,033
Location
A Zoo near YOU
Most likely a class II item in which case the single pole switching could be in either phase or neutral (seems to be something that our European cousins - until October - have adopted )
 

James the Spark1976

electricity is it real or just magic?
Electrician's Arms
Messages
314
Location
midlands
many electronic , rather than simply electrical, devices have a small continuous draw whilst on standby. you should be careful doing high voltage (insulation) tests on such an appliance. it can damage the components and turn a perfectly safe and functional appliance in to a piece of weee.
 
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M

mark641

EF Member
Messages
7
Location
egham
Thank you who replied. Plug is moulded so I cannot check it,
but while the knife was open I did check correct polarity.
R-Hobbs sent an email: it is faulty.
I will probably rewire to put the PCB downstream of the switch.
 

Wilko

Electrician's Arms
Messages
5,398
Location
Berkshire
Hi - good on you for help out and re using stuff.
In this case though, with a small £20 electrical appliance that Supplier states has a manufacturing defect - I’d just recycle it.
 

Lister1987

Trainee Access
Messages
72
Location
Runcorn
Thank you who replied. Plug is moulded so I cannot check it,
but while the knife was open I did check correct polarity.
R-Hobbs sent an email: it is faulty.
I will probably rewire to put the PCB downstream of the switch.

What did they deem the fault to be and the cause?
 

DPG

Respected Member
Messages
5,216
Location
S Yorkshire
Thank you who replied. Plug is moulded so I cannot check it,
but while the knife was open I did check correct polarity.
R-Hobbs sent an email: it is faulty.
I will probably rewire to put the PCB downstream of the switch.
I'm a big fan of recycling stuff and avoiding chucking stuff away, but I would think carefully before modifying a product, especially if it is to be sold/given to someone else.
 

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