PAT Testing IWBs

[Don Allen]

In Perth WA public schools we come across patch field that have an individual tag on each patch lead in the dimmer room, but the tester has only done a visual which is wrong but most schools do not know anything about testing and tagging. Another shortcut some testers do is a visual only for a dimmer rack instead of a full PAT test. We do a full circuit test using a heady duty extension lead, to do a full circuit and the Kyoritsu tester does an earth zero calibration for the test extension lead.

[sleah]

I'd assume that dimmers that are hard wired to the mains (regardless of output patch or hard wired to bars) would be treated the same as any other hard wired device, be it air-con, boiler controls or other building management system as far as testing is concerned?

I suppose the IWB's are slightly unique in that they can be essentially a glorified extension lead if terminated in a patch bay and not hard wired direct to a dimmer and so tested as you would a dom3st1c extension (give or take a couple of adaptors...)?

If IWBs are hard wired to the dimmer, do they then fall under building electrical testing, so similar to a lighting circuit that has wall plate dimmers rather than a simple switch? How do they test lighting circuits with out destroying dom3st1c dimmers?

[Simon Lewis]

How do they test lighting circuits with out destroying dom3st1c dimmers?

 

On Site Guide says to either temporarily disconnect them or join L & N together and test between that and the CPC.

It's probably wise to use a lower voltage too...

 

 

 

[Charlotte_R]

I'd assume that dimmers that are hard wired to the mains (regardless of output patch or hard wired to bars) would be treated the same as any other hard wired device, be it air-con, boiler controls or other building management system as far as testing is concerned?

I suppose the IWB's are slightly unique in that they can be essentially a glorified extension lead if terminated in a patch bay and not hard wired direct to a dimmer and so tested as you would a dom3st1c extension (give or take a couple of adaptors...)?

If IWBs are hard wired to the dimmer, do they then fall under building electrical testing, so similar to a lighting circuit that has wall plate dimmers rather than a simple switch? How do they test lighting circuits with out destroying dom3st1c dimmers?

 

The code of practice has been updated recently, but I would consider dimmers and anything on the load side of them to be part of the "fixed appliances". In fact, this kind of confusion is why the COP has been changed as a lot of things that were hardwired were seen by PAT testers as part of the fixed installation and by electricians as not being part of the fixed installation.

[sunray]

I'd assume that dimmers that are hard wired to the mains (regardless of output patch or hard wired to bars) would be treated the same as any other hard wired device, be it air-con, boiler controls or other building management system as far as testing is concerned?

I suppose the IWB's are slightly unique in that they can be essentially a glorified extension lead if terminated in a patch bay and not hard wired direct to a dimmer and so tested as you would a dom3st1c extension (give or take a couple of adaptors...)?

If IWBs are hard wired to the dimmer, do they then fall under building electrical testing, so similar to a lighting circuit that has wall plate dimmers rather than a simple switch? How do they test lighting circuits with out destroying dom3st1c dimmers?

 

The code of practice has been updated recently, but I would consider dimmers and anything on the load side of them to be part of the "fixed appliances". In fact, this kind of confusion is why the COP has been changed as a lot of things that were hardwired were seen by PAT testers as part of the fixed installation and by electricians as not being part of the fixed installation.

One of the Village Halls I have dealings with has a 'preferred electrician', [personally I think he's rubbish but I've never found anything of his actually wrong] who does all of the electrical work, regular testing, repairs etc but he refuses point blank to have anything to do with the stage lighting past the ring final provided for that use, even though it's only C14 plugs to 13A sockets and the lights/dimmer packs are brought out of storage when required. Edited April 26, 2021 by sunray

[Yorkie]

How do they test lighting circuits with out destroying dom3st1c dimmers?

 

On Site Guide says to either temporarily disconnect them or join L & N together and test between that and the CPC.

It's probably wise to use a lower voltage too...

 

Blummin nuisance. In an ideal world you test the whole of a lighting circuit, which is fine if all that involves is switching on all the lights and taking a few BC/ES/etc lamps out of their fittings. In practice, if you've got a combination of ELV halogen with transformers, fluorescent fittings with ballasts, fittings integrating LEDs and some dimmers it's going to be a long process to do a L-N IR test that goes beyond the switch. For an EICR it becomes a limitation. Same happens with other buildings and installations; I have seen church building EICR's done by companies who touched nothing more than 3m from the floor. Problem comes writing out an Electrical Installation Certificate for a board change; Limitations aren't strictly acceptable

[Simon Lewis]

Blummin nuisance.

 

And on top, you find that every ring circuit has had several outlets with built in USB chargers fitted ;-)