contactum rcd

[sellers]

My local wholesalers had started stocking contactum gear. Over the past 2 weeks I've had 2 2way boards off them with rcd main switch and both timed the rcd is upping the loop by around 0.5ohms. The circuits are well within the max zs and I know rcds can do this but 0.5ohms seems a lot!

 

[batty]

Have had that with some older BS4293 Rcd's not with modern ones though. I don't think Contactum switchgear is the same quality it used to be.

 

[ProDave]

I would avoid contactum. See my thread where I found out the hard way, that a comtactum 2 pole RCBO will self destruct in a puff of smoke if you feed the supply in to the bottom of the rcbo.

 

[batty]

I still use there switches and sockets only downfall with sockets now the screws are not backed off so a bit of extra time needed to install them.

 

[springcrocus]

My local wholesalers had started stocking contactum gear. Over the past 2 weeks I've had 2 2way boards off them with rcd main switch and both timed the rcd is upping the loop by around 0.5ohms. The circuits are well within the max zs and I know rcds can do this but 0.5ohms seems a lot!

About a year ago I started a thread about the difference between normal and no-trip Zs readings but it didn't garner much interest so let the thread die. At the time, I was using Contactum CUs and they returned much higher Zs readings on the no-trip test than by bypassing and doing a standard test.

Not sure if this is what you're refering to, but I have stopped using Contactum now because of this anomoly. It makes you wonder whether they have (relative) high-resistance contacts or the it's a function of the balance coil. Although I see the same effect with other makes of RCD, the readings are not so widely different as Contactum.