Instruction manual
56 KOMAC00607-09EN 
!
CAUTION 
If all power to the unit is turned off, the compressor heaters will become 
inoperable. Once power is resumed to the unit, the compressor and oil separator 
heaters must be energized a minimum of 12 hours before attempting to start the 
unit. 
Failure to do so can damage the compressors due to excessive accumulation of 
liquid in the compressor. 
Start-up After Temporary Shutdown 
1.  Insure that the compressor and oil separator heaters have been energized for at least 
12 hours prior to starting the unit. 
2.  Start the chilled water pump. 
3.  With System switch Q0 in the "on" position, move pumpdown switches Q1 and Q2 
to the "auto" position. 
4.  Observe the unit operation until the system has stabilized. 
Extended (Seasonal) Shutdown 
1.  Move the Q1 and Q2 (and Q3) switches to the manual pumpdown position. 
2.  After the compressors have pumped down, turn off the chilled water pump. 
3.  Turn off all power to the unit and to the chilled water pump. 
4.  If fluid is left in the evaporator, confirm that the evaporator heaters are operational. 
5.  Move the emergency stop switch S1 to the "off" position. 
6.  Close the compressor discharge valve and the optional compressor suction valve (if 
so equipped) as well as the liquid line shutoff valves. 
7.  Tag all opened compressor disconnect switches to warn against start-up before 
opening the compressor suction valve and liquid line shutoff valves. 
8.  If glycol is not
 used in the system, drain all water from the unit evaporator and 
chilled water piping if the unit is to be shutdown during winter and temperatures 
below -20°F can be expected. The evaporator is equipped with heaters to help 
protect it down to -20°F. Chilled water piping must be protected with field-installed 
protection. Do not leave the vessels or piping open to the atmosphere over the 
shutdown period. 
9.  Do not
 apply power to the evaporator heaters if the system is drained of fluids as 
this can cause the heaters to burn out. 
Start-up After Extended (Seasonal) Shutdown 
1.  With all electrical disconnects locked and tagged out, check all screw or lug-type 
electrical connections to be sure they are tight for good electrical contact. 
!
DANGER 
LOCK AND TAG OUT ALL POWER SOURCES WHEN CHECKING 
CONNECTIONS. ELECTRICAL SHOCK WILL CAUSE SEVERE PERSONAL 
INJURY OR DEATH. 
2.  Check the voltage of the unit power supply and see that it is within the ±10% 
tolerance that is allowed. Voltage unbalance between phases must be within ±3%. 
3.  See that all auxiliary control equipment is operative and that an adequate cooling 
load is available for start-up. 
4.  Check all compressor flange connections for tightness to avoid refrigerant loss. 
Always replace valve seal caps. 
5.  Make sure system switch Q0 is in the "Stop" position and pumpdown switches Q1 
and Q2 are set to "Pumpdown and Stop", throw the main power and control 










