Plug-in circuit breakers

Hi All,
I'm new to this forum. I've got an electronics background, but I'm not a licensed sparkie.. I bought a house a few years ago that didn't have a shed. Now I've built a shed and need to get an electrician to wire it up for me. The cable distance is just under 40m.

Looking at my house power board, I've got three phases coming in. Each passes through a 60Amp fuse before going to the meter. Then through a 3 way switch labelled 36A. From there the three phases are split across power, light, off-peak hot water and stove. There is a three phase RCD installed, but only in a single phase mode on the power circuits. All the fuses are ceramic old style with wire. I'm wondering about doing the following:
a. Have the ceramic fuses replaced with modern CB's or replace them with "plug-in CB's". You can get them in various sizes.
b. Do a full three phase run to the shed power board, or do a single phase run to the shed power board using a three phase cable (that would allow me to expand to three phases without having to redraw the cable if I ever need).
The RCD that is installed is a Clipsal 4EL40/4/30 old style. It was installed in June 2003. I'm wondering if I can have the light circuits connected up via it as well. Or would I be better of replacing it completely and have a new one installed for all three phases before they split out.

Any thoughts or advise..
Viking

Viking.

Electrician did mine.

Not 3 phase, but,
I have a circuit breaker in house fuse box.
This has FAT circuit, going to the shed.

I have a separate fusebox in the shed that splits the one circuit in the house fusebox into 3 circuits in the shed.
The fusebox in the shed has a separate breaker with RCD for each circuit.
My 3 circuits are lights, normal power points, 15Amp powerpoint.

Not the answer, but it will give you something to think about.

lpg_falcon.

Viking
Firstly how do you know the mains Fuses are 60 amp
(seems a bit high to me for 3 phase domestic)

Besides that
IMO get a sparkie in to replace the switchboard and put individual RCDs on individual light and power circuits

This way if you get a fault on a circuit you will only lose that circuit.
The way you have it now is you will lose all power.
(I'm not a fan of one RCD protecting many circuits for that reason)

When the sparkie replaces the switchboard he will upgrade your earth if needed thats got to be a good thing.

Also imo definitely put 3 phase on to your shed while you can.
You see 3 phase machinery for sale sometimes at a reasonable price