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Form 201.28-NM1.1
Issue date: 08/06/2021
General requirements
The units have been designed to operate continuously,
provided they are regularly maintained and operated
within the limitations given in this manual. Each unit
should be included in a routine schedule of daily main-
tenance checks by the operator or the customer, backed
up by regular service inspection and maintenance visits
by a suitably qualified Service Engineer.
It is entirely the responsibility of the owner to provide
for these regular maintenance requirements and to en-
ter into a maintenance agreement with a Johnson Con-
trols service organization to protect the operation of the
unit. If damage or a system failure occurs due to incor-
rect maintenance during the warranty period, Johnson
Controls is not liable for costs incurred to return the
unit to satisfactory condition.
This Maintenance section applies to the
basic unit only and may, on individual
contracts, be supplemented by additional
requirements to cover any modifications
or ancillary equipment as applicable.
The "Safety" section of this manual
should be read carefully before attempt-
ing any maintenance operations on the
unit.
Weekly maintenance
The following maintenance checks should be carried
out on a weekly basis by the operator/customer. Note
that the units are not generally user serviceable and
no attempt should be made to rectify faults or prob-
lems found during daily checks unless competent and
equipped to do so. If in any doubt, contact your local
Johnson Controls Service Agent.
Unit status
Press the 'STATUS' key on the keypad and ensure that
no fault messages are displayed.
Refrigerant leaks
Visually check the heat exchangers, compressors, and
pipework for damage and gas leaks.
JOHNSON CONTROLS
SECTION 9 - Maintenance
Operating conditions
Read the operating pressures and temperatures at the
control panel using the display keys and check that
these are within the operating limitations given in the
manual.
Compressor oil level
Compressor oil level will typically run below the bot-
tom of the sight glass. Oil levels will only be visible in
the sight glass after running for periods of 15 minutes
to 30 minutes at full compressor speed. Do not run with
oil levels above the sight glass. Be careful when view-
ing the sight glass not to confuse a full sight glass with
an empty sight glass.
Refrigerant charge
Ensure that there is a level of refrigerant in the evapo-
rator sight glass while running at Full Load for 15 min-
utes to 30 minutes.
Adding charge to a system
A sight glass is located in the evaporator. When opti-
mally charged after running full load, the refrigerant
level should be approximately in the center of the sight
glass. There should be little concern if the level is high
or low in the glass, it should not affect operation.
It is not necessary to weigh charge unless
the entire charge has been lost. The ease
of charging is possible since the micro-
channel coils hold only a small amount
of refrigerant charge. A charging valve,
located between the fixed orifice and the
evaporator, may be used if charge ad-
justment is required. Charge should be
added as liquid while circulating water
through the evaporator. If the complete
charge needs to be added, see Refriger-
ant Removal, Evacuation and Charging a
YVAA Chiller on page 166 in this section.
Use the valve on the liquid line for adding
the full charge and open the valves per
the procedure.
9
165
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