no class II markings

[hubsy]

No class II markings = class I test.

We have Rascal scanning equipment.

plug in IEC lead.

IEC lead passed test, after replacing 13a fuse with 3a fuse.

Switched mode power supply, 50-250vac input. 12vdc output.
no class II markings, all plastic body, but earth connection via the IEC lead. So Failed.

base station <40v so visual only.

rascal visual only.

We have over 600 of these units.

someone ain't pleased.

 

[Adam W]

I don't know what one of those is, but if there are 600 of them I'd be tempted to contact the manufacturer; it could be that there's a small hole somewhere to stick your probe.

 

[hubsy]

I have a thought of who to stick the probe into,

no seriously, no hole on power supply.

I have the same problem with a genuine power supply for my Dell laptop.

 

[steviebeck]

I would still test it as a class 1 item, is there a DC jack you can run a 200mA earth continuity test on sometimes you will get continuity on the end of the jack.. If not then I would mark it as no accessible earthed parts then IR test it as normal.

I have a dell charger and can definitely get earth continuity off the DC jack so worth trying both types of adaptor to see if this is the case.

 

[steviebeck]

What is the scanning equipment you are on about, what does it do does the scanner dock with the base station to charge?

I personally wouldn't check the base station as it is 12V DC or the scanner as it must be a 12V battery?

 

[hubsy]

as scanner is battery power <40volt is does not require testing.

Base station is powered from SM power supply.

The rascal scans magazines barcodes checking for out of date / returns / ordering.

 

[hubsy]

I would still test it as a class 1 item, is there a DC jack you can run a 200mA earth continuity test on sometimes you will get continuity on the end of the jack.. If not then I would mark it as no accessible earthed parts then IR test it as normal.

I have a dell charger and can definitely get earth continuity off the DC jack so worth trying both types of adaptor to see if this is the case.

Now that is very interesting.

I have just tried the PSU that I have to hand, and yes the Earth pin is connected to the 0volt of the jack plug.

will give it a try.

 

[hubsy]

Right then.
Tried a SMPS.

test: it equip class 1 earth leakage

tested power cord, earth bond lead 0.06ohm

earth bond 100ma 0.1ohm 5sec
insulation skip
sub leakage skip
leakage 230v 3.5ma 5sec
touch skip
polarity skip.


fails because 0.12ohm reading, but subtracting power lead leave 0.06ohm which is a pass.

thinks I will have to increase for combined lead and SMPS setting.

 

[steviebeck]

Hubsy

Looking at the figures you have above technically the power supply would fail on the leakage test. Page 96 of the cop has the leakage values and as the charger would be portable it would fail as over the limit of 0.75mA. What do you all think?

What tester are you using, I would be inclined to try an insulation resistance check if possible?

 

[hubsy]

Seaward europa, the settings are original as set by the manufacture.

its not hand held. Portable? its never moved or unplugged.

I'll need to check what the actual leakage is. possibly set the tester to 0.75ma and see what results I get.

will give feedback tomorrow.

 

[steviebeck]

Hubsy,

I think the europa does a 250V insulation test, I would be inclined to try that to see what the reading is?

It does say in the COP that sometimes due to large capacitors in SMPS's you might get a low reading, maybe try this and see as I would be interested to see the results!

 

[hubsy]

250v insulation test on an IT item, would that not cause damage to the electronics?

 

[steviebeck]

No the reduced voltage IR test is deemed safer for IT equipment and will be fine for your DC power supplies you are currently testing.

 

[hubsy]

thanks for that, I'll run some tests in the morning.

 

[hubsy]

No the reduced voltage IR test is deemed safer for IT equipment and will be fine for your DC power supplies you are currently testing.

reading p92 of COP, it says that a 'hard test' should not be done.
table 15.1
for 3core appliance lead set. (0.1+R)ohm where R is the resistance of the protective conductor of the supply cable.