Schreiber Chillers ASM010_Rev_C - Manual (Page 2)

S C H R E I B E R E N G I N E E R I N G
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h t t p : / / w w w . t r u e t o n . c o m
A DOVER INDUSTRIES COMPANY
12111 E. PARK STREET CERRITOS, CA 90703
CITY WATER-SWITCH OVER MODULE (ASM010) APPLICATION
GUIDE:
The module is designed to provide an alternative cooling medium to the process equipment in
the case of an alarm failure on the chiller. Two safety devices, high temperature alarm and
pressure switch are installed in the chiller to work companion with the ASM010 module. In the
case of failure of any of these devices, the ASM010 will switches to an alternative source of
cooling medium, providing that the module is set in Auto Mode.
The module required 110vac power input. Four (4) normally closed valves are installed to
provide the switching function. A check valve is installed in the city water supply line. This
prevents the possibility of chilled water drain during operation. The operator can set the module
to operate auto or manual mode. Refer to manual for instruction.
The plumbing connections that provided are 1”FPT. If the chiller is installed on top of the roof
above the ASM010, it is advised to install a check valve on the return chilled water line at the
module. This prevents return chilled water from siphons when switching action takes place in
Auto Mode.
In the case of pump failure, the module will switches to city water when set in auto mode. It will
reset once the pump is repaired. In the case of high temperature alarm, the module will also
switches to city water. Silent the alarm will force the module switch back to chilled water.
Now, the chiller is operating with an alarm and supply high temperature chilled water to the
process. If the alarm needs to be silent, the operator will have to turn off the chiller and set the
module in the manual mode and city water mode. This way, the chiller will stop operation until
the problem is solved. The city water is now supplying to the process equipment.
When water-glycol is utilized for cooling medium, precaution needed to be taken. The end user
must insure that operation of this module will not violate any local plumbing and environmental
codes. When module is automatically switches from chilled water to city water, small amount of
glycol mixture will goes to the drain due the volume of the mixture between the process
equipment and the module. To avoid losing water-glycol, a reserve tank is needed to hold the
mixture. This also applies for switching city water to chilled water. The extra amount of water
will dilute the water glycol, and decrease the heat transfer efficiency. Consult with manufacturer
for more information.