The phrase "a different set of instructions" is correct and usable in written English.
You can use it when referring to alternative guidelines or directions that differ from what has been previously provided.
Example: "If the first method doesn't work, please refer to a different set of instructions that I have attached."
Alternatives: "an alternative set of guidelines" or "another series of directions."
"I'm getting a different set of instructions every half-hour," complained Ana Murillo, a supermarket manager.
Mr. Annan, the United Nations secretary general, said in Brussels today that any force must have a different set of instructions from the current, toothless United Nations peacekeeping force, which is still in the southern Lebanon.
Take those ribosomes and give them a mixture of sugars, amino acids, adenosine triphosphate (the molecular compound that breaks down to provide energy for all biological functions) and new DNA with a different set of instructions on what to make and voila!
This instrument can deposit Ppy and different Abs on different electrodes; and, using a different set of instructions and reagents, it can run an ECD immunoassay to determine Ag concentration in one or more samples.
Each connector has a different set of instructions.
If you are writing according to a style manual that differs from the material presented above or for an instructor who wants you to follow a different set of instructions, follow the style manual or instructor's preferences.
Wait until you are all the way outside, if you are superstitious (which is an unhealthy way to live, but that's for another essay about a different set of operating instructions).
Each group was provided with a different set of written instructions on what they were supposed to do as each phrase was read aloud.
And we're for sure going to see this happen again at the Constitutional Convention — where, as we'll see, you end up with a lot of different instructions about what's supposed to be happening there, and people sort of have to figure out what direction to go based on interpreting each different set of instructions.
Students were divided into two groups of three classes each; the two groups received instruction on a different set of expressions.
"Subsequently, a different set of memory ordering rules are defined by the instruction-set architecture.
