How many instance resets an hour?

I had been going through the Scarlet Monastery gathering silk and enchanting reagents, and after clearing it I'd reset it and start again. After 5 times, I think, it told me I had "entered too many instances recently" and would not let me in.

I just want to confirm - is the instance reset limit 5 per hour, or per half hour, or what? I couldn't find any information on this.

Also, this would apply to not only this character but any of my characters on this account, correct?

If it's 5 per hour, it looks like I may have to go through more than one wing of the Monastery ..

Thanks in advance ..

-Shiluna Bluemoon