Hi Choirboy,
2400Watts is exactly 20 amps.
the DP-DMX20L can only handle 15 amps or if you change the power cord to a 12gauge cord, then it can do the full 20 amps.
I would recommend the following.
CYBER PACK - 20 AMPS 2400WATTS ETL APROVED
DP-640B - 40 AMPS 4800 WATTS UL APROVED.
Best regards,