Ambguity in Refrigeration tonnage of Chiller

My model is YPC-ST-400 meaning its TonsOfRefrigeration (TR) is 400
As can be seen we have total refrigerant (water) amount of 550kg

http://i59.tinypic.com/2h5mmjb.jpg

Using steam tables at (~5celsius) saturated properties of water:

Code:

SATURATED Sat. pressure 0.8718 kPa ~6.5mmHg Sat. temperature 5.0000 C Quality 1.0000 Moisture 0.0000 Enthalpy hf 21.0067 kJ/kg hfg 2489.7275 kJ/kg hg 2510.7342 kJ/kg Internal energy uf 21.0058 kJ/kg ufg 2361.4265 kJ/kg ug 2382.4323 kJ/kg Entropy sf 0.0762 kJ/kg/C sfg 8.9507 kJ/kg/C sg 9.0269 kJ/kg/C Specific volume vf 0.0010 m3/kg vfg 147.1621 m3/kg vg 147.1631 m3/kg

Thus at evaporator per kg water being evaporated @6.5mmHg will remove ~2489.7275kJ
of enthalpy from the chilled water. Assuming that ~60% of 550kg water is continously
circulated to evaporator we can calculate max. amount of enthalpy that is being
removed & then translate it to TR ...1TR=~3.5kW ...1kJ/sec=1kW

TR = 2489.7275kJ/kg x (550x0.6)kg/hr x 1hr/3600sec x 1TR/3.5kW = 65.2TR

Even if I had 100% water circulation to evaporator which is nonsense I cannot get the value 400TR?