I haven't been able to locate any support information online about your product, other than the email contact for support questions:
If the amp stays in protect mode all of the time, I would suspect a short in the speaker wiring or speaker(s) voice coil(s), or perhaps a faulty ground. If it plays for a short period of time and then goes into protect mode, it is most likely overheating. First check all of the wiring. Test your speakers on a known good amp and make sure there are no places in your wiring where the insulation may have been damaged, causing an intermittent problem.
Many owners have reported that this particular amp has a tendency to overheat. Also, when run in bridged mode, the speaker impedance needs to be at least 4 ohms. It will overheat if the impedance is below 4 ohms.
Hope this helps.