I assume you are turning off the main breaker before attaching the Akiko Audio products?
After reading the Akkio description what is a cupboard? Does the pro unit attach to the breaker box or to the outside meter?
"Cylindric Fuse Cartridge Silver has the great advantage of directly supplying power from your meter cupboard to your devices, without having it go through any inferior electromagnetic fuses. This positively influences alldevices in the rendering chain."
"The Harmonizer comes with a meter long connection cable and should be placed besides the meter cupboard.
Preferably connect this green/yellow cable to the same rail on which the earthing for the separate power cable of your audio/video set-up is also connected.
Since the cup board has to be opened for this, this is work for an qualified electrician.
Shorten the connection cable if possible.
Finally, mount the Harmonizer as close as possible to the meter cupboard using two self-tappers or screws."