Trane Arctic Manhattan Gen II, Installation, Operation And Maintenance Manual

Page: 51 / 88

ARTC-SVX001B-EN 51
N NO OT TIIC CE E
C Co om mp prre esssso orr D Da am ma ag ge e!!
F Fa aiillu urre e tto o ffo ollllo ow w iin nssttrru uccttiio on nss b be ello ow w cco ou ulld d rre essu ulltt iin n
e ex xtte en nssiiv ve e cco om mp prre esssso orr d da am ma ag ge e..
V Ve erriiffy y tth ha att ssu uccttiio on n p prre essssu urre e iiss ssu uffffiicciie en ntt.. S Se eccu urre e
tth he e cciirrccu uiitt o orr m mo od du ulle e o offfflliin ne e u un nttiill sstta attu uss cca an n b be e
e ex xa am miin ne ed d iin n d de etta aiill..
IIm mp po orrtta an ntt:: Extended operation with suction pressures
below 80 psi is a clear sign of insufficient
refrigerant charge, refrigeration
obstruction, or valve closed. This can cause
extensive damage to a compressor.
8. Check the refrigeration liquid line sight glass for
persistent bubbles (“flashing”) .
N No otte e:: Bubbles in the sight glass do not necessarily
indicate loss or lack of refrigerant charge.
Bubbles (commonly know as “flashing”) will
occur whenever the condenser fans cycle until
the expansion valve settles out the refrigerant
flow. Occasional bubbles also form when the
condenser head pressure control valve bypasses
hot gas around the condenser coil in low
ambient operation. If the refrigeration pressures
are in the normal range, the unit is most likely
adequately charged. “Flashing” could also
indicate excessive superheat adjustment of the
thermal expansion valve.
Quarterly
The quarterly maintenance inspection is a
comprehensive event that examines all aspects of the
chiller to identify early problems before they can
damage a chiller and require major repair or
refurbishment:
1. Inspect alarm log, refrigerant operating/static
pressures and temperature set points of each
module independently.
2. Inspect chiller superheat and sub-cooling. System
superheat should be 10 °F to 12 °F (5 °C to 6 °C).
System sub-cooling should be 10+ °F (5 °C)
depending on the ambient conditions.
3. Inspect the approach delta T - entering evaporator
water/glycol mixture temperature and leaving
refrigerant temperature.
4. Inspect strainers. Ensure bypass valve is properly
adjusted to a minimum of 25% open position.
5. Collect chilled water/glycol mixture sample for
professional analysis. Check for cleanliness. Drain
and refill with clean solution if excessive sludge or
dirt is present. Flush the chiller prior to refilling.
6. Inspect water/glycol mixture levels. Add glycol as
required.
7. If equipped, inspect crankcase heaters for proper
operation.
8. Inspect the water piping for signs of leaks at joints
and fittings.
9. Inspect refrigerant piping circuit for signs of oil or
refrigerant leakage. Conduct “sniffer test” to find
refrigerant leaks. Inspect all pressure switch
bellows.
10. Tighten all refrigeration piping connections (e.g.
rotalocks , Schrader valves, caps, and ball valves).
11. Install a manifold and gauge set to observe chiller’s
refrigeration operating pressures.
a. Verify that the pressure controls (low pressure
and high pressure switches) are “cutting in” and
“cutting out” at the appropriate pressures.
b. Verify refrigerant charge by recording the
superheat and sub-cooling temperatures.
c. Observe head pressure for signs of improper
condensing from clogged strainers, or a
modulating expansion valve issue.
12. Check compressor motor amperage draws and
voltage supplies and maintain a record of those
values. Verify that they are within the name plate
rating. Also, check for voltage imbalance. The
chiller’s phase monitor will open if the voltage
imbalance exceeds 4%.
13. Check for chattering, excessive wear or burned
contacts on motor starters. Replace contacts, if in
doubt. It is recommended to replace contactors
every 5-6 years.
Annually
The annual chiller maintenance inspection is critical to
the long-term performance of the chiller. Whether a
chiller has a service life of 15 years or 30 years is
almost entirely dependent upon how consistently and
how diligently the annual maintenance inspection and
tasks are performed. The annual event is a
comprehensive inspection that examines all aspect of
the chiller to identify and repair small problems before
they can become major issues that damage a chiller
and require significant repair or refurbishment.
1. Inspect all electrical connections for damage and
ensure terminals are tight. Inspect all contactors for
pitting and corrosion and replace as necessary. It is
recommended to replace contactors every 5-6
years.
W WA AR RN NIIN NG G
H Ha azza arrd do ou uss V Vo olltta ag ge e!!
F Fa aiillu urre e tto o d diisscco on nn ne ecctt p po ow we err b be effo orre e sse errv viicciin ng g cco ou ulld d
rre essu ulltt iin n d de ea atth h o orr sse erriio ou uss iin njju urry y..
D Diisscco on nn ne ecctt a allll e elle eccttrriicc p po ow we err,, iin nccllu ud diin ng g rre em mo otte e
d diisscco on nn ne eccttss b be effo orre e sse errv viicciin ng g.. F Fo ollllo ow w p prro op pe err
llo occkko ou utt//tta ag go ou utt p prro occe ed du urre ess tto o e en nssu urre e tth he e p po ow we err
cca an n n no ott b be e iin na ad dv ve errtte en nttlly y e en ne errg giizze ed d.. V Ve erriiffy y tth ha att n no o
p po ow we err iiss p prre esse en ntt w wiitth h a a v vo ollttm me ette err..
M Ma aiin ntte en na an ncce e P Prro occe ed du urre ess