Working Conditions; Scheduled Maintenance - York YGWH 115 Installation, Commissioning & Operation

Form 6S6I-B01C-EOMA-EN (0318)
Evaporator tubes
The standard evaporator tubes used in YGWH Chillers
are internally enhanced copper tubes.
If the equipment is located in an unheated
area that is susceptible to freezing, the
water must be drained from the evaporator
to prevent tube damage from freezing.
Maintain evaporator water or brine flow rates
through the evaporator tubes that the chiller was
designed for. Refer to the engineering data on the sales
order form for the correct flow rates. Generally, the water
or brine that is circulated through the evaporator is part
of closed loop circuit that is treated with chemicals to
prevent the formation of scale and debris.
Evaporator
It is difficult to determine by a particular test whether
possible lack of performance of water evaporator is
due to fouled tubes alone or due to a combination of
troubles. Trouble which may be due to fouled tubes is
indicated when, over a period time, the cooling capacity
decreases and the split (temperature difference
between the water leaving the evaporator and the
refrigerant temperature in the evaporator) increases. A
gradual drop off in cooling capacity can also be caused
by a gradual leak of refrigerant from the system or by a
combination of fouled tubes and shortage of refrigerant
charge. An excessive quantity of oil in the evaporator
can also contribute to erratic performance.
If cleaning of the evaporator tubes is required, follow
the condenser cleaning procedure.

Working conditions

Read the working pressures and temperatures from the
OptiView™ LT panel pages. Confirm that these values
are within the working limits.
7-4

Scheduled Maintenance

All maintenance operations should be carried out on a
regular basis by a suitably qualified Service Engineer,
It should be noted that the interval necessary between
each 'minor' and 'major' service can vary depending on,
for instance, application, site conditions and expected
operating schedule. Normally a minor 'service' should
be carried out every three to six months and a 'major'
service once a year. It is recommended that your local
York Service Centre is contacted for recommendations
for individual sites.
EN