No, the amount is not limited, however, there is a limitation for the number of times one account can be used to receive a direct deposit. This is seen more with families allowing their children to use their account to receive the direct deposit.
"In an effort to combat fraud and identity theft, new IRS procedures effective January 2015 will limit the number of refunds electronically deposited into a single financial account or pre-paid debit card to three. The fourth and subsequent refunds automatically will convert to a paper refund check and be mailed to the taxpayer." See IRS Direct Deposit Limits
If this is the case you will receive a notice informing you that the account has exceeded the direct deposit limits and that you will receive a paper refund check in approximately four weeks if there are no other issues with the return. You can track your refund at Where’s My Refund?
If by chance there was an issue with the IRS being able to deposit your refund into your bank account, the bank will send them a notice and the funds back which will cause the IRS to issue a refund by check. This check will be mailed to the address on file.
