Yeah, it's the rtf arrays that are overflowing, not the psf ones. As the "CHARMM size" only influences the latter, changing it won't help.
What vibhor should have done is look at the FAQ
before posting. Also, the exact same question has been asked and answered countless times on these forums; here are just 3 of the occurrences returned to me by the forum's search function (note that the recurrence of this question despite its presence in the FAQ had already exceeded my annoyance threshold as far back as 2010):
What is the use of a public forum if people don't make use of its accumulated knowledge?! Heck, even just copy-pasting the error message into Google
takes you straight to the right answer, in a fraction of the time it takes to get the same answer through the forums, and without wasting any experts' time. Also see the forum guidelines