I have a 220 outlet for my air-conditioner. I just got a tanning bed,also 220. The cord on tanning bed is too short to reach the outlet. Is it ok if i make an extension cord to reach the outlet?
Depends what you mean by "make".
If you mean hokey-doke something together out of random bits, then no.
But if you have the skill/experience/attention to detail, that is needed for good workpersonship... and go down to a competent electrical supplier and get some #14/3 SJOOW cordage (noting that cordage numbering does count the ground)... and get a NEMA 6-15R socket and 6-15P plug whose strain relief is compatible with the cord size... and assemble them competently according to instructions... and the strain reliefs work properly on the cable sheath... and you check it in-service for heat where none should be... then yeah. Build away.
It could also be built with 6-20 plug/socket and 12 AWG cordage. However the plug and socket must match, and a 6-20 plug will not fit a 6-15 (Ms. Nope) socket in the wall.
Unless you really know what you're doing, I'd hold off on making an extension cord for your tanning bed. 220 (240) volts is nothing to mess with. The instructions that came with the tanning bed probably say not to use an extension cord and doing so would void the warranty. You can probably get a 220 Volt appliance cord at your home store or an electrical supply company but I wouldn't recommend that. Your best bet would be to have someone that knows what they're doing make a longer cord and terminate it in the tanning bed panel. Any chance of moving the bed closer to the outlet or relocating the outlet closer to the bed? You don't want to be tripping over that cord. Good luck and stay safe out there.
To make a cord you need $9 and $14 cord ends, cord for about $1/ft, or you could by a $25 cord on Amazon.
If the blades on the plug line up with each other search NEMA 6-15 extension cord, if opposing NEMA 6-20.
The instructions from the tanning bed probably says not to use an extension cord, the instructions are part of the UL listing. Could be due to resistance of the cord length, tripping hazard, compliance with the NEC regarding receptacle location for appliance locations or who knows what other reasons they have, if it says so I won't second guess.