Should not be a problem. However breakers can wear out if they have tripped several times, i.e. each successive trip might be at a slightly lower amperage. The ratings posted for the CS are the maximum they will draw based on the rated voltage. Amps, volts and watts are part of a mathematical equation which is Volts x Amps = Watts.
So if your electric service is providing 110 volts and you have a 15 amp circuit, it can handle 1650 watts. If your electric service is delivering 120 volts then a 15 amp circuit can handle 1800 watts.
Either way, the CS 50 & 55 are 1200 watt units. Now if you have other items taking power off the same circuit, you have to figure in the wattage of those other items.
Hopefully, that answers your question, even though it is a long answer.