Worst case they'll force you to put it back, which again takes no time or money.
Incorrect.
Likely case is they make you pay for their licensed electrician to come in and put it back at whatever rate the local union charges. Even worse is the house burns down and the fire marshal sees your "mod" and declares it your fault causing the landlords insurance company to back out and point at you. But, enough fear mongering
What you have is a nema 10-30 plug. Commonly known as an "old dryer plug". There is no easy way of safely converting it to a nema 6-30 unless someone ran four wires to the box and only hooked up 3. But looking at the vintage of that plug I would consider that unlikely. That outlet has two lives and a neutral. There is no ground. Don't get me going on how someone could come up with a design that has a 110/220 volt appliance in a laundry room that is not grounded ... that's another story.
The "correct" thing would be to upgrade that plug to a "new dryer plug" which is a nema 14-30. That will give you both lives for 220 along with neutral for 120 and ground. You can safely piglead convert that to a nema 6-30. Your landlord can not stop you from performing that upgrade by a licensed electrician in most states. He may even split the cost.
Disclaimer: I am not a licensed electrician and this post does not constitute advice. But please, verify what you have been told since much of what precedes my post is not only wrong, but dangerous. A piglead conversion from a nema 10-30 to a 6-30 would be ungrounded.
incorrect. the old drier plug has a ground and 2 hot leads. Although it is an irrelevant argument because the neutral is bonded to ground at the meter, at the transformer on the pole and most of the time inside the panel. Although the function of them is different, In most cases the only difference between the ground and the neutral is the color.
