PAT FAIL HELP - 19" Rack Mounted Surge Protected Power Strip

Ulaephon · Apr 17, 2024

Hi All,

My colleague and I are currently doing PAT/ISITEE Testing, and we've hit a snag with a bit of equipment - we've got 19" Racks for our equipment that each have a Surge Protected Extension Lead mounted into them, they're Class I, and we test them on 250V. Earth Cont. and IEC Cont. are both fine, but Insulation Resistance is reading below the minimum 1Mohm that a Class I appliance should have, they're reading 0.52Mohm.

We're unsure whether they Pass or Fail as we know that Surge Protected leads would fail a typical test, and we've tested them at lower voltage, but we don't know what to do with them.

If anyone could lend any insight to what they would do, would be greatly appreciated.

newfutile · Apr 18, 2024

SPD would usually pass at 250v dc but not at 500 v ,it could be the spd itself . i would contact the manufacturer for advice and expected readings

Ulaephon · Apr 18, 2024

newfutile said:
SPD would usually pass at 250v dc but not at 500 v ,it could be the spd itself . i would contact the manufacturer for advice and expected readings

They were bought off Amazon, unsure what manufacturer;

We've also had a couple that have tested above the 1Mohm mark, and we've spoken with our GM and we'll see how many total have failed as to what we do moving forwards - we have agreed to take them out of use and may replace them or look at other options

UKMeterman · Apr 18, 2024

There is an other issue wit useing 19" racks on 13A plugs, the earth leakage of all the kit addeds up. If you have an earth condutor break then all that kit becomes live and give someone a nasty shock. Put the surge protection at the distribution board, use some decent ABB or similar surge kit. As for the sockets have a look at Olson and consider a 16A commando socket.

davesparks · Apr 19, 2024

UKMeterman said:
Put the surge protection at the distribution board, use some decent ABB or similar surge kit.

You have no control over what is installed in the buildings the racks get taken to so whatever protection is required needs to be in the rack.

UKMeterman said:
As for the sockets have a look at Olson and consider a 16A commando socket.

That's ok as long as every where you take it has 16A outlets, otherwise it will just be plugged in via a 13-16 adaptor.

UKMeterman · Apr 19, 2024

davesparks said:
You have no control over what is installed in the buildings the racks get taken to so whatever protection is required needs to be in the rack.

That's ok as long as every where you take it has 16A outlets, otherwise it will just be plugged in via a 13-16 adaptor.

Have a look at electrical.------.org/wiring-matters/years/2022/93-november-2022/high-protective-conductor-currents-in-electrical-installations/ the current in the protective conductor could be 3.5mA for each class 1 appliance.
I stand by my comment about surge protection, cheap surge protection is a fire hazard.

replace the ---- with the iet no space

davesparks · Apr 19, 2024

UKMeterman said:
Have a look at electrical.------.org/wiring-matters/years/2022/93-november-2022/high-protective-conductor-currents-in-electrical-installations/ the current in the protective conductor could be 3.5mA for each class 1 appliance.
I stand by my comment about surge protection, cheap surge protection is a fire hazard.

replace the ---- with the iet no space

Yes, but unless you are permanently installing the rack somewhere you have little control over what supply is going to be available or how it is protected.

Yes cheap surge protection could be dangerous, but that doesn't mean surge protection can't be installed in a rack, just that it should be of a good quality.

mainline · Apr 19, 2024

UKMeterman said:
There is an other issue wit useing 19" racks on 13A plugs, the earth leakage of all the kit addeds up. If you have an earth condutor break then all that kit becomes live and give someone a nasty shock. Put the surge protection at the distribution board, use some decent ABB or similar surge kit. As for the sockets have a look at Olson and consider a 16A commando socket.

How would using a commando instead of a 13amp plug make any difference when there's a loss of the cpc, You're still going to have the same accumulated earth leakage.