Advantage OACS Series, Инструкция по эксплуатации

Страница: 54 / 86

OACS Central Chillers : with MG Series Control Instrument
Page: 54
ADVANTAGE ENGINEERING, INC.
525 East Stop 18 Road Greenwood, Indiana 46142
317-887-0729 Fax: 317-881-1277
Service Department Fax: 317-885-8683
Email: service@AdvantageEngineering.com
5.4 Optional AUTOMATIC WATER MAKE-UP SYSTEM service (Only units in
no freeze climates)
A. The automatic water make-up system consists of a level
switch and a solenoid valve (figure 5.4B). When the tank
level is low the level switch signals the solenoid valve to
open allowing make-up water to re-fill the tank.
B. Level switch maintenance and service.
1. The level switch contacts engage and disengage
the water make-up solenoid valve.
2. Poor water quality can allow debris or a film build-up on the level switch contacts
which can impair operation. Clean the contacts on a regular basis. If cleaning the
contacts does not remedy the problem the level switch must be replaced.
C. Make-up solenoid valve service.
1. The make-up solenoid valve may require service
for a failed coil or more often it will not fully close
because debris from poor make-up water quality is
in the valve mechanism.
2. To replace the coil, disengage power from the unit
following all lock-out tag-out procedures. Remove
the wires from the failed coil and remove the coil
from the valve stem. Install the new coil on the
stem and reconnect the wires.
3. To service the solenoid valve follow the procedure below.
a. Disengage process operations according to the procedure outlined in this
manual. Be certain process fluid pressure is relieved (coolant pressure
gauge reads “0”) and water system flow is shut off.
b. Disengage main power supply. The operator must follow all lockout/
tagout procedures.
c. Remove or open any access cover panel and set aside to gain access to
the make-up solenoid valve.
d. The solenoid valve can be disassemble by removing the 4 retaining
screws.
e. Keeping all electrical connections intact, lift the coil and top solenoid
base assembly and set aside.
f. Note the arrangement of the core spring and core assembly,
diaphragm spring and diaphragm assembly. (See diagram.)
g. Clean all components as required.
Typical water make-up solenoid valve
Typical water make-up level switch