I'm not sure what you mean. Disconnect turntable from the mains or disconnect motor from the ac switch of turntable?
If you mean the later, it is not needed. The wires are long enough for servicing in situ. Another thing I was afraid of, is that someone may replace wires incorrectly or worse break of the pins in the switch box. In all the years I worked on these motors I never removed the cables unless the stator needed changing.
If it is the mains supply, I hope that it's self evident and by removing the turntable from the base/plinth it would require this step already.
I appreciate any suggestion and consider them always as constructive.
Klaus Adlhoch, fmr. Assistant Service Manager,
Noresco -N.Q.I.-Dual of Canada,
Area of expertise: Tech Training and Consumer Service P.R.
Associated with Dual till Thompson era.
Favorite Duals: TG 12a, 1009, 721.