Schreiber Chillers 15MEDAC email - Manual (Page 25)

CHILLER SYSTEMS:
CHILLED WATER CIRCUIT
All of the bypassed water returns to the reservoir through the evaporators. The return
line water is diverted to both evaporators.
The pump motor is INTERNALLY overload protected. In the case of an overload the
pump will shut off. The controller will show a “CIRCUIT #1 Flow” error. When the alarm
is reset, the pump will restart if the motor has cooled down to the point where the
overload is closed. If the overload is still open, the controller will try to restart the
pump, but will generate another flow error after the pump start up time delay.
Any time the flow error is reset, the compressors will turn on automatically if cooling is
required.
A wye strainer is installed in the return line to prevent the evaporators from fouling. If
there is a noticeable drop in flow, the wye strainer may be full. It can be cleaned by
opening the cleanout valve on the front of the chiller. This must be done while the
pump is running. A small bucket should be place under the valve to catch debris and
water that will l=come out of the valve. The valve only needs to be open for a few
seconds.
Chilled Water Reservoir
The insulated chilled water reservoir inside the chiller is designed to eliminate wide
swings in temperature during changing loads. It also provides a convenient location
from adding water and glycol to the system.
A float in the reservoir tells the controller that the water level is too low. The low lever
alarm still allows the chiller to run, but water must be added immediately. Since the
reservoir is open to the atmosphere, a small amount of water may be lost due to
evaporation. The local weather conditions will dictate how often the reservoir should be
topped off. If water needs to be added more than once a month, there is a possibility of
a leak in the system.
Flow Switch
There is a flow switch on each piping loop to protect the chilled water system. When
the switch is open (no flow) the pump on that loop will not run. If the flow switch is
open, it will also lock out the compressors to keep from freezing the evaporators. On
pump startup, there is a short time delay 15-25 seconds, to allow flow to be established
before generating an error. When running, there is another time delay of 5-10 seconds