The North Penn School District is warning parents about a potential telephone scam involving school lunch accounts. The caller tells parents their child has a low balance and asks them to make a credit card deposit over the phone.  A North Penn website notice says the district will never call anyone asking for a telephone deposit.  Parents can pay with cash or a check at their child’s school or use Visa or MasterCard on the internet through mySchoolBucks.com, a secure transaction gateway.  There are no reports of any North Penn parents being victimized, and the school district is simply passing along a warning from the Pennsylvania Education Department.