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Step 4 – Check Refrigerant Valves
During shipment or installation it is possibe valves
where closed. Verify that all refrigerant valves are
open.
CAUTION: Do not operate the unit with the
compressor, oil line, or liquid line service
valves “CLOSED”. Failure to have these “OPEN”
may cause serious compressor damage.
Step 5 – Verify Freezestat Setting
Make sure the Freezestat is set appropriately for the
operating conditions of the chiller. The Freezestat
setting is in a password protected menu of the
chiller controller. Refer to the Controller Operation
Section for instruction on how to access this menu,
It should be set at 10°F below the minimum chilled
water temperature setting that the chiller will be
operating. Reference Table 21 to be sure the
coolant solution has sufficient freeze protection
(glycol) to handle at least 5°F below the Freezestat
setting. All chillers are shipped from the factory with
the Freezestat set at 38°F. This is done to protect
against a possible freeze-up if no glycol has been
added to the coolant. Once the proper glycol
solution has been added, the Freezestat can be
adjusted to the appropriate setting.
CAUTION: The manufacturer’s warranty does not
cover the evaporator from freezing. It is vital that
the Freezestat is set properly.
Step 6 – Turn On Control Power
Turn on the control power by turning the control
power switch to "On". The panel displays should now
be illuminated. Due to extreme ambient
temperatures that the unit may be exposed to
during shipment, the High Refrigerant Pressure
switch may have tripped. If this is the case,
disconnect the main power and reset the High
Refrigerant Pressure by depressing the manual reset
button located on the switch. Reconnect the main
power and turn the control power on by pressing the
Power button. Clear the alarm condition by pressing
the Alarm Reset button.
Step 7 – Establish Coolant Flow
Standard units are provided with an internal pump
that can be energized by pressing the Start button. If
the unit has been customized and does not have an
internal pump, the external pump should be
energized to establish flow through the chiller.
Note: The compressor will not start as long as the flow switch
is open. A positive flow must be established through the
evaporator before the compressor can operate.
Set water flow using a discharge throttling valve or
flow control valve (by others). The valve should be
the same size as the To Process connection of the
chiller. Standard chillers are designed for
approximately 2.4 gpm/ton of nominal capacity. A
significant increase in flow beyond this in a standard
chiller may result in excessive pressure loss and
negatively impact chiller efficiency and in extreme
cases may cause premature wear or damage of
internal components.
Step 8 – Intial Unit Operation
Entering the desired leaving fuid temperature on the
control panel. Unless otherwise specified, the chiller
is factory set to deliver coolant at 50°F. Adjust to the
desired operating temperature. The chiller should
now be controlling to the selected temperature.
Please note that if there is insufficient load the
compressor may cycle on and off causing swings in
temperature.
WARNING: Under no circumstances should the
High Refrigerant Pressure or the Low Compressor
Pressure switch be deactivated. Failure to heed
this warning can cause serious compressor
damage, severe personal injury or death.
Operate the system for approximately 30 minutes.
Check the liquid line sight glass. The refrigerant flow
past the sight glass should be clear. Bubbles in the
refrigerant indicate either low refrigerant charge or
excessive pressure drop in the liquid line. A shortage
of refrigerant is indicated if operating pressures are
low and subcooling is low. Normal subcooling
ranges are from 10°F to 20°F. If subcooling is not
within this range, check the superheat and adjust if
required. The superheat should be approximately
10°F. Since the unit is factory charged, adding or
removing refrigerant charge should not be
necessary. If the operating pressures, sight glass,
superheat, and subcooling readings indicate a
refrigerant shortage, charge refrigerant 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.
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