SBM Electrical Solutions Ltd in Oldham

This company installed an RCD unit for me back in 2007. Everything appeared to be ok until I had an electrician round to fix a lighting fault. He got real confused until he suggested the polarity was crossed and had a look at the RCD unit. Sure enough his assumption was correct so he corrected it for me at no extra cost.
I saw it for myself and I know quite a lot about electrics.