How can I fix my Bosch angle grinder GWS 21-230H i cut te electric lead?

Be sure to reconnect the wires of identical colours. You should have a black (neutral), white or red (live) and a naked or green (ground) wires.
Remove the outside sleeve for about 4 to 6 cm on each sides.
Remove the insulation over about an 2~3 cm on both sides of the cut. Twist the wires together for a little more than 1 cm with some wire going past the twisted part. Double back that extra, still twisting it around the already twisted part. This is to ensure a beter physical link.
Cover the repair with some electric tape or heat shrink sleeve. Do it for each individual wires.
Once all wires are individualy reconnected and taped, use more tape to wrap the whole repair. You may also use heat shrink sleeve here. Next, as a finishing touch, you can use some hockey stick fabric tape to cover the electric tape. It's adesive is more durable and it help protect and secure the repair.

Maybe, in the process of cuting it, it got violently yanked. In this case, the contact in the grider can have been broken. Check that and fix if needed.

If that don't work, there is some problem with the plug, or there are some hiden breakage in the wire.
Get a new 3 conductors wire. It must be rated to at least 1.5 times that amperage rating of your grinder. If the new wire is over 3 m long, overrate it by at least 2 times.
Overrating the wire ensure that you can have the full power. It also prevent overheating the wire, reducing fire hasard.
If you need a new electric plug, it should also be overrated.
Overrating the electric plug ensure that it won't get to hot under heavy use.

Electro
October 2013