the refrigerant charg ing valve, (Figure 7 and Figure 8) or to the pumpout charging connec t ion.
First evacuate the ni tro gen holding charge from t he vessels. Charge the r ef rigerant as a gas
until the system pressure exceeds 35 psig (141 kPa). After the machine is beyond this pressure
the refrigerant shou ld be charged as a liquid unt il all of the recommended refrigerant charge has
been added.
Trimming Refrigerant Charge
The 17/19EX is shipped with the correct charg e for the design duty of the machine. Trimmin g
the charge can be best acc om pl ished when design load is av a ilable. To trim, chec k the
temperature differen ce between leaving chil led water temperatu r e and cooler refrigerant
temperature at full loa d design conditions. If nec es s a ry, add or remove refri ger a nt to bring the
temperature diff erence to desig n conditions o r a minimum dif ferential.