130 RTAC-SVX01J-EN
Unit Start-Up Procedures
Daily Unit Start-Up
The time line for sequence of operation is shown in
Figure 43, p. 132 and Figure 44, p. 134 and depicts the
nominal delays and sequences that a chiller would
experience during a typical operational cycle.The time
line begins with a power up of the main power to the
chiller.The sequence assumes a 2 circuit, 2 compressor air-
cooled RTAC chiller with no diagnostics or malfunctioning
components. External events such as the operator placing
the chiller in Auto or Stop, chilled water flow through the
evaporator, and application of load to the chilled water
loop causing loop water temperature increases are
depicted and the chillers responses to those events are
shown, with appropriate delays noted.The effects of
diagnostics, and other external interlocks other than
evaporator water flow proving, are not considered.The
response of the EasyView Display is also depicted on the
time line.
Note: Unless the CH530 TechView and building
automation system are controlling the chilled
water pump, the manual unit start sequence is as
follows. Operator actions are noted.
General
If the pre-start checkout, has been completed, the unit is
ready to start.
1. Press the STOP key on the CH530.
2. As necessary, adjust the setpoint values in the CH530
menus usingTechView.
3. Close the fused-disconnect switch for the chilled water
pump. Energize the pump(s) to start water circulation.
4. Check the service valves on the discharge line, suction
line, oil line and liquid line for each circuit.These valves
must be open (backseated) before starting the
compressors.
5. Press the AUTO key. If the chiller control calls for
cooling and all safety interlocks are closed, the unit will
start.The compressor(s) will load and unload in
response to the leaving chilled water temperature.
6. Verify that the chilled water pump runs for at least one
minute after the chiller is commanded to stop (for
normal chilled water systems).
Once the system has been operating for approximately 30
minutes and has become stabilized, complete the
remaining start-up procedures, as follows:
1. Check the evaporator refrigerant pressure and the
condenser refrigerant pressure under Refrigerant
Report on the CH530TechView.The pressures are
referenced to sea level (14.6960 psia).
2. Check the EXV sight glasses after sufficient time has
elapsed to stabilize the chiller.The refrigerant flow past
the sight glasses should be clear. Bubbles in the
refrigerant indicate either low refrigerant charge or
excessive pressure drop in the liquid line or a stuck
open expansion valve. A restriction in the line can
sometimes be identified by a noticeable temperature
differential between the two sides of the restriction.
Frost will often form on the line at this point. Proper
refrigerant charges are shown in the General
Information Section.
Important: A clear sight glass alone does not mean that
the system is properly charged. Also check
system subcooling, liquid level control and
unit operating pressures.
3. Measure the system subcooling.
4. A shortage of refrigerant is indicated if operating
pressures are low and subcooling is also low. If the
operating pressures, sight glass, superheat and
subcooling readings indicate a refrigerant shortage,
gas-charge refrigerant into each circuit, as required.
With the unit running, add refrigerant vapor by
connecting the charging line to the suction service
valve and charging through the backseat port until
operating conditions become normal.
Seasonal Unit Start-Up Procedure
1. Close all valves and re-install the drain plugs in the
evaporator.
NOTICE:
Compressor Damage!
Ensure that the compressor and oil separator heaters
have been operating for a minimum of 24 hours before
starting. Failure to do so could result in equipment
damage.
NOTICE:
Compressor Damage!
Catastrophic damage to the compressor will occur if
the oil line shut off valve or the isolation valves are left
closed on unit start-up
NOTICE:
Equipment Damage!
If both suction and discharge pressures are low but sub-
cooling is normal, a problem other than refrigerant
shortage exists. Do not add refrigerant, as this could
result in overcharging the circuit.
Use only refrigerants specified on the unit nameplate
(HFC 134a) and Trane OIL00048. Failure to do so may
cause compressor damage and improper unit operation.
To Next Page
Loading...
Need help?
General
