item with a metal case and no earth wire in the plug

[deimos2020]

Performing the PAT inspection on some science equipment and I have found some items that were passed by the previous company that performed it however it failed the earth bond test and has a metal case its a air pump. upon closer inspection, I found that they only have two core wires and have had an English 3-pin plug added after receipt at the company. the box says it has to be earthed before use and there is a labeled screw on the outside for an earth point to be attached.

my question is "is there any way for these to pass a PAT Inspection and should they have been passed previously

thanks for your help

 

[Paul L]

They probably tested it on the Class 2 setting on their tester which would technically pass but if it definitely requires an earth but has been wired in 2 core cable this must have been altered at a later stage. Seems odd that this would be done but maybe they were having problems with it and decided to make it work somehow.
If it needs that earth connection i would take it out of service until it gets the proper connections put on it.

 

[DPG]

Unfortunately a lot of people doing PAT (or ISITEE as it should be known) don't fully understand the tests they are doing. And as we know, just because the tester says PASS doesn't mean the right tests have been done, or the correct results obtained.

I think I've mentioned before about watching someone testing figure 8 mains leads. PASS, PASS, PASS.......

 

[deimos2020]

They probably tested it on the Class 2 setting on their tester which would technically pass but if it definitely requires an earth but has been wired in 2 core cable this must have been altered at a later stage. Seems odd that this would be done but maybe they were having problems with it and decided to make it work somehow.
If it needs that earth connection i would take it out of service until it gets the proper connections put on it.

thanks that's what I thought.
I think the device is designed to have an external earth so it always had a 2-core cable you were just expected to wire it into the earth when it was set up.

 

[littlespark]

You can get metal cases items that are class II…. Just look at some of the decorative light fittings on the market.

However, if there’s a label saying “this must be earthed” then the question is, why was it rewired with only a 2 core lead?

 

[DPG]

You can get metal cases items that are class II…. Just look at some of the decorative light fittings on the market.

However, if there’s a label saying “this must be earthed” then the question is, why was it rewired with only a 2 core lead?

I've seen this before on some scientific equipment. Possibly because it may be connected to a different earth point to avoid hum loops etc (similar to some audio equipment).

I'd be tempted to fasten an earth wire to the mains cable and connect it up so that it can't be missed out in future use.

 

[pirate]

Connect an earth as suggested by @DPG
Test again and see what the result is...
Some lab gear is supplied "bare" for wiring locally